Nov 8, 2022 | News releases, Research findings
Childhood Trauma
Mental Health
Physical Health
Above: The logos for the Healthy Nevada Project, DRI, and Renown Health.
Childhood Traumas Strongly Impact Both Mental and Physical Health
Adult risk for obesity, chronic pain, migraines, and mental disorders increases in proportion to the number and types of traumas experienced in childhood
The social environments we grow up in are critical when determining our wellbeing and health later in life. Most Americans (67%) report experiencing at least one traumatic event in childhood, and a new study shows that these experiences have significant impacts on our health risks as adults. Physical illnesses such as obesity and chronic pain are affected, but mental disorders show the most significant association, including post-traumatic stress disorder (PTSD), bipolar disorder, substance abuse, and depression.
Scientists from DRI and the University of Nevada, Reno, led the study, published on Oct. 6 in the journal Frontiers in Psychiatry. More than 16,000 people from the Reno area volunteered for the research as part of the Healthy Nevada Project, one of the most visible genomic studies in the United States powered by Renown Health. Participants answered questions about their social environments before age 18, including experiences with emotional, physical, or sexual mistreatment, neglect, and substance abuse in the household. The researchers combined this information with anonymized medical records to build on existing research about how childhood traumas affect health outcomes.
“The study provides insight as to how social determinants of health may influence adult health disorders,” said Robert Read, M.S., a researcher at the Center for Genomic Medicine at DRI and one of the study’s lead authors.
Nearly two-thirds (66%) of participants recalled at least one type of trauma, and almost one-quarter (24%) reported experiencing more than four. Women and people of African American and Latinx descent reported a higher prevalence of traumatic experiences than men and those with European ancestry, but people in low-income households were the most impacted.
Thirteen mental illnesses showed the most statistically significant associations, including mood disorders, depression, PTSD, anxiety disorders, eating disorders, schizophrenia, and substance abuse. For every reported type of abuse experienced in childhood, a participant’s risk for PTSD increased 47%. Each cumulative trauma also increased one’s risk for making a suicide attempt by 33%.
The researchers note that although the study is rooted in Nevada — which has high rates of adults with mental illness and poor access to care — it provides a window into deeply rooted public health issues across the nation.
“Combatting the prevalence of childhood traumas is a complex problem,” said Karen Schlauch, Ph.D., a bioinformatics researcher at DRI and one of the study’s lead authors. “Personal experiences with neglect and abuse are more challenging to address, but many of the underlying issues can be tackled at the community level, like food insecurity and poverty.”
Beyond improving our understanding of how early social environments influence our health, Schlauch says that the next target for research is understanding how childhood traumas may be linked with specific traits like impulsivity — a prominent trait in Nevada’s gambling communities.
“In order to address the devastating impacts of early-life adversity on local population health and inequities, we must focus on the dominant social and behavioral mechanisms affecting Nevadans,” said Stephanie Koning, Ph.D., an assistant professor at the School of Public Health at the University of Nevada, Reno, and study co-author. “Beyond how population needs drive our research, we are partnering with community-based organizations to promote evidence-based interventions across individual, community, and state levels.”
As the study team expands their analysis of the health impacts of early-life adversity, they are exploring how to use the Healthy Nevada Project database to inform community-based interventions. They’ve partnered with community institutional partners — including the Stacie Mathewson Behavioral Health & Addiction Institute and Northern Nevada HOPES — for research and advocacy focused on promoting healthy childhood social environments and well-being throughout an individual’s life.
More information:
The full text of the study, Using phenome-wide association studies and the SF-12 quality of life metric to identify profound consequences of adverse childhood experiences on adult mental and physical health in a Northern Nevadan population, is available from Frontiers in Psychiatry: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9583677/.
This project was funded by the Stacie Mathewson Behavioral Health and Addiction Institute, Renown Health, and the Renown Health Foundation. Study authors included Karen Schlauch (DRI), Robert Read (DRI), Stephanie Koning (UNR), Iva Neveux (DRI), and Joseph Grzymski (DRI/Renown Health).
For more information on the Healthy Nevada Project®, please visit: https://healthynv.org/.
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About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
About Renown
Renown Health is the region’s largest, locally governed, not-for-profit integrated healthcare network serving Nevada, Lake Tahoe and northeast California. With a diverse workforce of more than 7,000 employees, Renown has fostered a longstanding culture of excellence, determination and innovation. The organization comprises a trauma center, two acute care hospitals, a children’s hospital, a rehabilitation hospital, a medical group and urgent care network, and the region’s largest, locally owned not-for-profit insurance company, Hometown Health. Renown is currently enrolling participants in the world’s largest community-based genetic population health study, the Healthy Nevada Project®. For more information, visit renown.org.
About the University of Nevada, Reno
The University of Nevada, Reno, is a public research university that is committed to the promise of a future powered by knowledge. Nevada’s land-grant university founded in 1874, the University serves 21,000 students. The University is a comprehensive, doctoral university, classified as an R1 institution with very high research activity by the Carnegie Classification of Institutions of Higher Education. Additionally, it has attained the prestigious “Carnegie Engaged” classification, reflecting its student and institutional impact on civic engagement and service, fostered by extensive community and statewide collaborations. More than $800 million in advanced labs, residence halls and facilities has been invested on campus since 2009. It is home to the University of Nevada, Reno School of Medicine and Wolf Pack Athletics, maintains a statewide outreach mission and presence through programs such as the University of Nevada, Reno Extension, Nevada Bureau of Mines and Geology, Small Business Development Center, Nevada Seismological Laboratory, and is part of the Nevada System of Higher Education. Through a commitment to world-improving research, student success and outreach benefiting the communities and businesses of Nevada, the University has impact across the state and around the world. For more information, visit www.unr.edu.
Mar 9, 2022 | News releases, Research findings
Childhood Trauma
Genetics
Obesity
Above: The logos for the Healthy Nevada Project, DRI, and Renown Health.
Childhood trauma and genetics linked to increased obesity risk
New study from the Healthy Nevada Project® shows strong influence of genes and environment on human health
Reno, Nev. (March 9, 2022) –New research from the Healthy Nevada Project® found associations between genetics, obesity, and childhood trauma, linking social health determinants, genetics, and disease. The study, which was published this week in Frontiers in Genetics, found that participants with specific genetic traits and who experience childhood traumas are more likely to suffer from adult obesity.
In 2016, DRI and Renown Health launched the Healthy Nevada Project®, the nation’s first community-based, population health study, which now has more than 60,000 participants. The project is a collaboration with personal genomics company, Helix, and combines genetic, environmental, social, and clinical data to address individual and community health needs with the goal of improving health across the state and the nation.
The new study focuses on Adverse Childhood Experiences (ACEs), which are traumatic and unsafe events that children endure by the age of 18. Over 16,000 participants in the Healthy Nevada Project® answered a mental health survey, and more than 65 percent of these individuals self-reported at least one ACE occurrence. These 16,000 participants were cross-referenced with their genetic makeup, and clinical Body Mass Index (BMI) measures.
According to the research team’s findings, study participants who had experienced one or more types of ACE were 1.5 times more likely to become obese adults. Participants who experienced four or more ACEs were more than twice as likely to become severely obese.
“Our analysis showed a steady increase in BMI for each ACE a person experienced, which indicates a very strong and significant association between the number of adverse childhood experiences and adult obesity,” said lead author Karen Schlauch, Ph.D., of DRI. “More importantly, participants’ BMI reacted even more strongly to the occurrence of ACEs when paired with certain mutations in several genes, one of which is strongly associated with schizophrenia.”
“We know that genetics affect disease in the Healthy Nevada Project® [https://pubmed.ncbi.nlm.nih.gov/31888951/], and now we are recognizing that ACEs also affect disease,” said Healthy Nevada Project® Principal Investigator Joseph Grzymski, Ph.D., of DRI and Renown Health. “Our new study shows that the combination of genes and environmental factors like ACEs, as well as many social determinants of health, can lead to more serious health outcomes than either variable alone. More broadly, this new work emphasizes how important it is for population genetic studies to consider the impact of social determinants on health outcomes.”
The study team believes that it is important for clinical caregivers to understand the strong impact that negative childhood experiences such as ACEs can have on both child and adult health. The researchers hope the information from this study will encourage doctors and nurses to conduct simple screenings for ACEs and consider a patient’s social environment and history in combination with genetics when developing treatment plans for better patient health.
According to the 2019 Youth Behavior Risk Survey (YRBS), 25.6 percent of Washoe County teenagers are overweight or obese. Obesity is a serious health concern for children and adolescents. According to the Centers for Disease Control and Prevention, obese children and adolescents are more likely to become obese as adults.
“Obese and overweight children and adolescents are at risk for multiple health problems during their youth, which are likely to be more severe as adults,” said Max J. Coppes, MD, PhD, MBA, FAAP, Nell J Redfield Chair of Pediatrics at the University of Nevada Reno School of Medicine, Physician in Chief of Renown Children’s Hospital. “Obese and overweight youth are more likely to have risk factors associated with cardiovascular diseases, such as high blood pressure, high cholesterol, and type 2 diabetes. Losing weight, in addition to a healthy diet, helps to prevent and control multiple chronic diseases and improves quality of life for a lifetime.”
“We’d like to thank all of the Healthy Nevada Project® participants who provided information to make our work possible,” said Robert Read, M.S., of DRI. “Our research illustrates that it’s not just genetics that cause disease, but that our environment and life experiences interact with our genes to impact our health in ways that we are only beginning to understand.”
Many thanks to Renown Health, the Stacie Mathewson Behavioral Health and Addiction Institute, and the Center for Genomic Medicine at DRI for supporting this significant work. Renown is currently enrolling participants in the world’s largest community-based genetic population health study, the Healthy Nevada Project®. For more information, visit renown.org.
More information:
The full text of the study, The Impact of ACEs on BMI: An Investigation of the Genotype-Environment Effects of BMI, is available from Frontiers in Genetics: https://www.frontiersin.org/articles/10.3389/fgene.2022.816660/full
This project was funded by the Stacie Mathewson Behavioral Health and Addiction Institute, Renown Health, and the Renown Health Foundation. Study authors included Karen Schlauch (DRI), Robert Read (DRI), Iva Neveux (DRI), Bruce Lipp (DRI), Anthony Slonim (Renown Health), and Joseph Grzymski (DRI/Renown Health).
For more information on the Healthy Nevada Project®, please visit: https://healthynv.org/
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About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
About Renown
Renown Health is the region’s largest, locally governed, not-for-profit integrated healthcare network serving Nevada, Lake Tahoe and northeast California. With a diverse workforce of more than 7,000 employees, Renown has fostered a longstanding culture of excellence, determination and innovation. The organization comprises a trauma center, two acute care hospitals, a children’s hospital, a rehabilitation hospital, a medical group and urgent care network, and the region’s largest, locally owned not-for-profit insurance company, Hometown Health. Renown is currently enrolling participants in the world’s largest community-based genetic population health study, the Healthy Nevada Project®. For more information, visit renown.org.
Media contacts:
Kelsey Fitzgerald, DRI
Senior Communications Official
775-741-0496
Kelsey.fitzgerald@dri.edu
Renown Public Relations
775-691-7308
news@renown.org
Feb 13, 2022 | News releases, Research findings
Baylor University paleoclimatologist analyzed gypsum- and quartz-dominated dune systems for possible fine, breathable dust fluxes detrimental to human health
Above: Mark Sweeney and Eric McDonald set up measurements of PI-SWERL at White Sands National Park. Credit: Baylor University.
Reportsed from Baylor University: https://www.baylor.edu/mediacommunications/news.php?action=story&story=226267
WACO, Texas – A recent National Science Foundation funded study that included Baylor University paleoclimatologist Steven L. Forman, Ph.D., professor of geosciences, evaluates current and future dust sources in central North America with consideration for climate change. These fine dust fluxes are detrimental to asthmatic and general cardio-pulmonary health for populations downwind, particularly areas of west Texas and New Mexico that have large areas of significant dust sources with dry and drought conditions in the past decade.
The study, published in Geology, seeks to characterize dust emission potential from landforms in two end-member eolian systems, where wind is the primary source of sediment transport: the White Sands dune field in New Mexico and the Monahans dune field in west Texas. The study’s lead author is Mark Sweeney, Ph.D., University of South Dakota. Eric McDonald, Desert Research Institute, joined Sweeney and Forman on the research team.
The White Sands dune field is composed of gypsum and a hot spot for dust emissions because the dunes and adjacent playa yield high dust fluxes. However, the active Monahans dune field is composed of quartz and produce low dust fluxes. Adjacent to Monahans, stabilized sand sheets and dunes that contain silt and clay could produce high dust fluxes if reactivated by climate change or anthropogenic disturbance.
“We chose these sites because the gypsum dunes and playa lake environments should be hot spots for dust emission, and the Monahans composed of mostly pure quartz grains should be a low dust emission system. We were wrong about the Monahans,” Forman said.
Field- and model-based estimates of dust emissions from dune systems are difficult to characterize. By considering whole eolian systems — active and stabilized dunes, interdunes, sand sheets and playas — dust emissions can be more accurately estimated for estimating current and future atmospheric dust loading. Atmospheric dust has impacts on radiative forcing, biogeochemical cycles, extreme climate variability and human health.
The researchers utilized a Portable In Situ Wind Erosion Laboratory (PI-SWERL) to measure the dust emission potential in the field. The PI-SWERL, which was developed by a team from DRI, is a circular wind-erosion device, measures concentrations of inhalant particulate matter at different friction velocities from soil surfaces.
“The PI-SWERL is wind tunnel wrapped into a circle which makes this novel technology portable,” Forman said. “Thus, we can quantify the winds speeds and forces necessary to loft small, breathable particle sizes that at certain elevated concentrations induce an asthmatic response and heightened risk of pulmonary mortality and morbidity.”
The PI-SWERL measurements showed considerable differences in the dust emission potential across both systems. Active dunes, sand sheets and interdunes at White Sands generated similarly high dust fluxes. Comparatively, the playa had the widest range of fluxes with the lowest fluxes on moist or hard surfaces and the highest where loose sand and aggregates were at the surface.
In contrast, the Monahans active quartz dunes generated low dust fluxes. However, dry crusted interdunes with loose sand at the surface had much higher fluxes. Dust emissions increase exponentially with rising wind friction velocities for both systems, often associated with common winds 10 to 15 mph.
The results revealed intra- and extra-landform variability in dust fluxes from eolian systems, mostly due to the degree of surface crusting or soil moisture. More dust occurs on surfaces with loose sand or aggregates where saltation bombardment, when wind lifts particles and causes them to hit along the surface with increased velocity, could erode playas or interdunes and aggregates could break apart to create more dust.
Surprisingly, White Sands showed high magnitudes of dust emission from the abrasion of dune sand and erosion of playa sediments, indicating both landforms are particulate sources during dust storms. The Monahans system produced low dust emissions due to low rates of abrasion in active dunes and vegetative cover, which protects the surface from wind erosion. However, the most common landforms — sand sheets that surround the dune fields for miles — are rich sources for fine breathable particles, at the same magnitude as White Sands.
“The most surprising results was variability in dust emissivity for White Sands landforms and the very high dust flux from the flat sand sheet area that covers most surfaces in west Texas. There is a hidden dust source in these deposits and soils, which were unrecognized,” Forman said.
Dust emission assessments are important to current and future climate modeling. Wind-dominated and drought-sensitive systems could see stabilized dunes and sand sheets become reactivated, or adjacent playas may increase emissions. Potential atmospheric dust loading can occur from diverse landforms in active and presently stabilized eolian systems.
“Atmospheric dust concentrations are important for the global heat-balance and locally can lead to a thermal-blanking effect raising local temperatures. Recent studies associate ozone degradation with elevated dust concentrations high in the atmosphere,” Forman said. “As our planet warms from increasing greenhouse gases many deserts will expand, and grassland areas like on the Southern High Plains will diminish, revealing a limitless supply of dust that will worsen aridity and is detrimental to human health. Understanding the land surface response to climate warming is critical for future sustainability.”
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About Baylor University
Baylor University is a private Christian University and a nationally ranked Research 1 institution. The University provides a vibrant campus community for more than 20,000 students by blending interdisciplinary research with an international reputation for educational excellence and a faculty commitment to teaching and scholarship. Chartered in 1845 by the Republic of Texas through the efforts of Baptist pioneers, Baylor is the oldest continually operating University in Texas. Located in Waco, Baylor welcomes students from all 50 states and more than 90 countries to study a broad range of degrees among its 12 nationally recognized academic divisions.
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Nov 22, 2021 | News releases, Research findings
Within an Antarctic Sea Squirt, Scientists Discover a Bacterial Species With Promising Anti-Melanoma Properties
December 1, 2021
RENO, NEV.
By Kelsey Fitzgerald
Antarctic Sea Squirt
Melanoma
Health
Above: Late spring at Arthur Harbor. The waters surrounding Anvers Island, Antarctica, are home to a species of sea squirt called Synoicum adareanum. New research has traced the production of palmerolide A, a key compound with anti-melanoma properties, to a member of this sea squirt’s microbiome.
Credit: Alison E. Murray, DRI
New study brings important advances for Antarctic science and natural products chemistry
There are few places farther from your medicine cabinet than the tissues of an ascidian, or “sea squirt,” on the icy Antarctic sea floor – but this is precisely where scientists are looking to find a new treatment for melanoma, one of the most dangerous types of skin cancer.
In a new paper that was published today in mSphere, a research team from DRI, Los Alamos National Laboratory (LANL), and the University of South Florida (USF) made strides toward their goal, successfully tracing a naturally-produced melanoma-fighting compound called “palmerolide A” to its source: a microbe that resides within Synoicum adareanum, a species of ascidian common to the waters of Antarctica’s Anvers Island archipelago.
“We have long suspected that palmerolide A was produced by one of the many types of bacteria that live within this ascidian host species, S. adareanum,” explained lead author Alison Murray, Ph.D., research professor of biology at DRI. “Now, we have actually been able to identify the specific microbe that produces this compound, which is a huge step forward toward developing a naturally-derived treatment for melanoma.”
Synoicum adareanum in 80 feet of water at Bonaparte Point, Antarctica. New research has traced the production of palmerolide A, a key compound with anti-melanoma properties, to a suite of genes coded in the genome by a member of this sea squirt’s microbiome.
Credit: Bill J. Baker, University of South Florida.
The full study, Discovery of an Antarctic ascidian-associated uncultivated Verrucomicrobia with anti-melanoma palmerolide biosynthetic potential, is available from mSphere.
The bacterium that the team identified is a member of a new and previously unstudied genus, Candidatus Synoicihabitans palmerolidicus. This advance in knowledge builds on what Murray and her colleagues have learned across more than a decade of research on palmerolide A and its association with the microbiome (collective suite of microbes and their genomes) of the host ascidian, S. adareanum.
In 2008, Murray worked with Bill Baker, Ph.D., professor of chemistry at USF and Christian Riesenfeld, Ph.D., postdoctoral researcher at DRI to publish a study on the microbial diversity of a single S. adareanum organism. In 2020, the team expanded to include additional researchers from LANL, USF, and the Université de Nantes, and published new work identifying the “core microbiome” of S. adareanum – a common suite of 21 bacterial species that were present across 63 different samples of S. adareanum collected from around the Anvers Island archipelago.
In the team’s latest research, they looked more closely at the core microbiome members identified in their 2020 paper to determine which of the 21 types of bacteria were responsible for the production of palmerolide A. They conducted several rounds of environmental genome sequencing, followed by automated and manual assembly, gene mining, and phylogenomic analyses, which resulted in the identification of the biosynthetic gene cluster and palmerolide A-producing organism.
“This is the first time that we’ve matched an Antarctic natural product to the genetic machinery that is responsible for its biosynthesis,” Murray said. “As an anti-cancer therapeutic, we can’t just go to Antarctica and harvest these sea squirts en masse, but now that we understand the underlying genetic machinery, it opens the door for us to find a biotechnological solution to produce this compound.”
“Knowing the producer of palmerolide A enables cultivation, which will finally provide sufficient quantity of the compound for needed studies of its pharmacological properties,” added Baker.
A diver collects samples of Synoicum adareanum in support of a microbiome and biosynthetic gene cluster study. Palmer Station Antarctica, March 2011.
Credit: Bill Dent, University of South Florida.
Many additional questions remain, such as how S. adareanum and its palmerolide-producing symbiont are distributed across the landscape in Antarctic Oceans, or what role palmerolide A plays in the ecology of this species of ascidian. Likewise, a detailed investigation into how the genes code for the enzymes that make palmerolide A is the subject of a new report soon to be published.
To survive in the harsh and unusual environment of the Antarctic sea floor, ascidians and other invertebrates such as sponges and corals have developed symbiotic relationships with diverse microbes that play a role in the production of features such as photoprotective pigments, bioluminescence, and chemical defense agents. The compounds produced by these microbes may have medicinal and biotechnological applications useful to humans in science, health and industry. Palmerolide A is one of many examples yet to be discovered.
“Throughout the course of disentangling the many genomic fragments of the various species in the microbiome, we discovered that this novel microbe’s genome appears to harbor multiple copies of the genes responsible for palmerolide production,” said Patrick Chain, Ph.D., senior scientist and Laboratory Fellow with LANL. “However the role of each copy, and regulation, for example, are unknown. This suggests palmerolide is likely quite important to the bacterium or the host, though we have yet to understand it’s biological or ecological role within this Antarctic setting.”
“This is a beautiful example of how nature is the best chemist out there,” Murray added. “The fact that microbes can make these bioactive and sometimes toxic compounds that can help the hosts to facilitate their survival is exemplary of the evolutionary intricacies found between hosts and their microbial partners and the chemical handshakes that are going on under our feet on all corners of the planet.”
Andrew Schilling (University of South Florida) dives in 100 feet of water at Cormorant Wall, Antarctica. Samples for microbiome characterization were collected by SCUBA divers working in the chilly subzero seas off Anvers Island, in the Antarctic Peninsula.
Credit: Bill J. Baker, University of South Florida.
More information:
The full study, Discovery of an Antarctic ascidian-associated uncultivated Verrucomicrobia with antimelanoma palmerolide biosynthetic potential, is available from mSphere.
Study authors included Alison Murray (DRI), Chein-Chi Lo (LANL), Hajnalka E. Daligault (LANL), Nicole E. Avalon (USF), Robert W. Read (DRI), Karen W. Davenport (LANL), Mary L. Higham (DRI), Yuliya Kunde (LANL), Armand E.K. Dichosa (LANL), Bill J. Baker (USF), and Patrick S.G. Chain (LANL).
This study was made possible with funding from the National Institutes of Health (CA205932), the National Science Foundation (OPP-0442857, ANT-0838776, and PLR-1341339), and DRI (Institute Project Assignment).
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About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
About The University of South Florida
The University of South Florida is a high-impact global research university dedicated to student success. Over the past 10 years, no other public university in the country has risen faster in U.S. News and World Report’s national university rankings than USF. Serving more than 50,000 students on campuses in Tampa, St. Petersburg and Sarasota-Manatee, USF is designated as a Preeminent State Research University by the Florida Board of Governors, placing it in the most elite category among the state’s 12 public universities. USF has earned widespread national recognition for its success graduating under-represented minority and limited-income students at rates equal to or higher than white and higher income students. USF is a member of the American Athletic Conference. Learn more at www.usf.edu.
About Los Alamos National Laboratory
Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is managed by Triad, a public service oriented, national security science organization equally owned by its three founding members: Battelle Memorial Institute (Battelle), the Texas A&M University System (TAMUS), and the Regents of the University of California (UC) for the Department of Energy’s National Nuclear Security Administration. Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.
Nov 4, 2021 | News releases, Research findings
Above: Researchers’ ice core drilling camp on Colle Gnifetti in 2015. Two ice cores extracted from this area preserved a continuous one-thousand-year record of European climate and vegetation. Credit: Margit Schwikowski.
Evidence preserved in glaciers provides continuous climate and vegetation records during major historical events
Reposted from AGU – https://news.agu.org/press-release/1000-years-of-glacial-ice-reveal-prosperity-and-peril-in-europe/
RENO, Nev. – Europe’s past prosperity and failure, driven by climate changes, has been revealed using thousand-year-old pollen, spores and charcoal particles fossilized in glacial ice. This first analysis of microfossils preserved in European glaciers unveils earlier-than-expected evidence of air pollution and the roots of modern invasive species problems.
A new study analyzed pollen, spores, charcoal and other pollutants frozen in the Colle Gnifetti glacier on the Swiss and Italian border. The research found changes in the composition of these microfossils corresponded closely with known major events in climate, such as the Little Ice Age and well-established volcanic eruptions.
The work was published in Geophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences.
The industrialization of European society also appeared clearly in the microfossil record and, in some cases, showed up sooner than expected. Pollen from the introduction of non-native crops was found to go back at least 100 years ago and pollution from the burning of fossil fuels shows up in the 18th century, about 100 years earlier than expected.
Existing historical sources such as church records or diaries record conditions during major events like droughts or famines. However, studying data from the glaciers contributes to the understanding of climate and land use surrounding such events, providing non-stop context for them with evidence from a large land area. Precisely identifying the timing of these events can help scientists better understand current climate change.
“The historical sources that were available before, I don’t think [the sources] got the full picture of the environmental context,” said Sandra Brugger, a paleoecologist at the Desert Research Institute in Nevada and lead researcher on the study. “But also, with the ice core, we couldn’t get the full picture until we started collaborating with historians on this. It needs those two sides of the coin.”
Evidence on High
The new study analyzed microfossils frozen in two 82- and 75-meter-long ice cores pulled from the Colle Gnifetti glacier, which are the first two ice cores from the continent of Europe studied for microfossils. Similar studies have sampled ice cores in South America, Central Asia and Greenland, but those regions lack the breadth of written historical records that can be directly correlated with the continuous microfossil data in ice cores.
Over the centuries, wind, rain and snow carried microfossils from European lowlands, the United Kingdom and North Africa to the exposed glacier. Ice in this glacier site dates back tens of thousands of years, and the altitude of Colle Gnifetti — 4,450 meters above sea level — means the ice was likely never subjected to melting, which would mix the layers of samples and create uncertainty in the chronology of the record.
“They can actually pinpoint and identify the relationships between what’s happening on the continent with climatic records inherent in the ice,” said John Birks, a paleoecologist at the University of Bergen who was not associated with the study. “They can develop, in a stronger way, this link between human civilization and change and climate, particularly in the last thousand years or so where conventional pollen analysis is rather weak.”
Evidence of pollution due to fossil fuel combustion also appeared earlier in the chronological record than expected. The researchers found evidence of the early burning of coal in the United Kingdom around 1780, much earlier than the expected onset of industrialization around 1850, which could have implications for global climate change modeling.
The records also showed evidence of pollen from non-native European plants from 100 years ago, showing a long legacy of the existing ecological problems created by invasive species transported across continents through trade.
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AGU (www.agu.org) supports 130,000 enthusiasts to experts worldwide in Earth and space sciences. Through broad and inclusive partnerships, we advance discovery and solution science that accelerate knowledge and create solutions that are ethical, unbiased and respectful of communities and their values. Our programs include serving as a scholarly publisher, convening virtual and in-person events and providing career support. We live our values in everything we do, such as our net zero energy renovated building in Washington, D.C. and our Ethics and Equity Center, which fosters a diverse and inclusive geoscience community to ensure responsible conduct.
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Oct 6, 2021 | News releases, Research findings
Early Human Activities Impacted Earth’s Atmosphere More Than Previously Known
Oct 6, 2021
RENO, NV
By Kelsey Fitzgerald
Climate Change
Earth’s Atmosphere
Ice Cores
Above: After a storm at the drilling camp on James Ross Island, northern Antarctic Peninsula.
New study links an increase in black carbon in Antarctic ice cores to Māori burning practices in New Zealand more than 700 years ago
The James Ross Island core drilled to bedrock in 2008 by the British Antarctic Survey provided an unprecedented record of soot deposition in the northern Antarctic Peninsula during the past 2000 years and revealed the surprising impacts of Māori burning in New Zealand starting in the late 13th century. Robert Mulvaney, Ph.D., pictured here led collection of the core.
Reno, Nev. (October 6, 2021) – Several years ago, while analyzing ice core samples from Antarctica’s James Ross Island, scientists Joe McConnell, Ph.D., and Nathan Chellman, Ph.D., from DRI, and Robert Mulvaney, Ph.D., from the British Antarctic Survey noticed something unusual: a substantial increase in levels of black carbon that began around the year 1300 and continued to the modern day.
Black carbon, commonly referred to as soot, is a light-absorbing particle that comes from combustion sources such as biomass burning (e.g. forest fires) and, more recently, fossil fuel combustion. Working in collaboration with an international team of scientists from the United Kingdom, Austria, Norway, Germany, Australia, Argentina, and the U.S., McConnell, Chellman, and Mulvaney set out to uncover the origins of the unexpected increase in black carbon captured in the Antarctic ice.
The team’s findings, which published this week in Nature, point to an unlikely source: ancient Māori land-burning practices in New Zealand, conducted at a scale that impacted the earth’s atmosphere across much of the Southern Hemisphere and dwarfed other preindustrial emissions in the region during the past 2,000 years.
“The idea that humans at this time in history caused such a significant change in atmospheric black carbon through their land clearing activities is quite surprising,” said McConnell, research professor of hydrology at DRI who designed and led the study. “We used to think that if you went back a few hundred years you’d be looking at a pristine, pre-industrial world, but it’s clear from this study that humans have been impacting the environment over the Southern Ocean and the Antarctica Peninsula for at least the last 700 years.”
Four ice cores from continental Antarctica were drilled in East Antarctica, including two as part of the Norwegian-American International Polar Year Antarctic Scientific Traverse.
Tracing the black carbon to its source
To identify the source of the black carbon, the study team analyzed an array of six ice cores collected from James Ross Island and continental Antarctica using DRI’s unique continuous ice-core analytical system. The method used to analyze black carbon in ice was first developed in McConnell’s lab in 2007.
While the ice core from James Ross Island showed a notable increase in black carbon beginning around the year 1300, with levels tripling over the 700 years that followed and peaking during the 16th and 17th centuries, black carbon levels at sites in continental Antarctica during the same period of time stayed relatively stable.
Andreas Stohl, Ph.D., of the University of Vienna led atmospheric model simulations of the transport and deposition of black carbon around the Southern Hemisphere that supported the findings.
“From our models and the deposition pattern over Antarctica seen in the ice, it is clear that Patagonia, Tasmania, and New Zealand were the most likely points of origin of the increased black carbon emissions starting about 1300,” said Stohl.
After consulting paleofire records from each of the three regions, only one viable possibility remained: New Zealand, where charcoal records showed a major increase in fire activity beginning about the year 1300. This date also coincided with the estimated arrival, colonization, and subsequent burning of much of New Zealand’s forested areas by the Māori people.
This was a surprising conclusion, given New Zealand’s relatively small land area and the distance (nearly 4,500 miles), that smoke would have travelled to reach the ice core site on James Ross Island.
“Compared to natural burning in places like the Amazon, or Southern Africa, or Australia, you wouldn’t expect Māori burning in New Zealand to have a big impact, but it does over the Southern Ocean and the Antarctic Peninsula,” said Chellman, postdoctoral fellow at DRI. “Being able to use ice core records to show impacts on atmospheric chemistry that reached across the entire Southern Ocean, and being able to attribute that to the Māori arrival and settlement of New Zealand 700 years ago was really amazing.”
Black carbon deposition during the past 2000 years measured in ice cores from Dronning Maud Land in continental Antarctica and James Ross Island at the northern tip of the Antarctic Peninsula. Atmospheric modeling and local burning records indicate that the pronounced increase in deposition in the northern Antarctic Peninsula starting in the late 13th century was related to Māori settlement of New Zealand nearly 4000 miles away and their use of fire for land clearing and management. Inset shows locations of New Zealand and ice-core drilling sites in Antarctica.
Research impacts
The study findings are important for a number of reasons. First, the results have important implications for our understanding of Earth’s atmosphere and climate. Modern climate models rely on accurate information about past climate to make projections for the future, especially on emissions and concentrations of light-absorbing black carbon linked to Earth’s radiative balance. Although it is often assumed that human impacts during preindustrial times were negligible compared to background or natural burning, this study provides new evidence that emissions from human-related burning have impacted Earth’s atmosphere and possibly its climate far earlier, and at scales far larger, than previously imagined.
Second, fallout from biomass burning is rich in micronutrients such as iron. Phytoplankton growth in much of the Southern Ocean is nutrient-limited so the increased fallout from Māori burning probably resulted in centuries of enhanced phytoplankton growth in large areas of the Southern Hemisphere.
Third, the results refine what is known about the timing of the arrival of the Māori in New Zealand, one of the last habitable places on earth to be colonized by humans. Māori arrival dates based on radiocarbon dates vary from the 13th to 14th century, but the more precise dating made possible by the ice core records pinpoints the start of large scale burning by early Māori in New Zealand to 1297, with an uncertainty of 30 years.
“From this study and other previous work our team has done such as on 2,000-year old lead pollution in the Arctic from ancient Rome, it is clear that ice core records are very valuable for learning about past human impacts on the environment,” McConnell said. “Even the most remote parts of Earth were not necessarily pristine in preindustrial times.”
Measuring the chemistry in a longitudinal sample of an ice core on DRI’s unique ice core analytical system.
Additional information:
The full study, Hemispheric black carbon increase after 13th C Māori arrival in New Zealand, is available from Nature: https://www.nature.com/articles/s41586-021-03858-9
Study authors included Joseph R. McConnell (DRI), Nathan J. Chellman (DRI), Robert Mulvaney (British Antarctic Survey), Sabine Eckhardt (Norwegian Institute for Air Research), Andreas Stohl (University of Vienna), Gill Plunkett (Queen’s University Belfast), Sepp Kipfstuhl (Alfred Wegener Institut, Germany) , Johannes Freitag (Alfred Wegener Institut, Germany), Elisabeth Isaksson (Norwegian Polar Institute), Kelly E. Gleason (DRI/Portland State University), Sandra O. Brugger (DRI), David B. McWethy (Montana State University), Nerilie J. Abram (Australian National University), Pengfei Liu (Georgia Institute of Technology/Harvard University), and Alberto J. Aristarain (Instituto Antartico Argentino).
This study was made possible with funding from the National Science Foundation (0538416, 0968391, 1702830, 1832486, and 1925417), the DRI, and the Swiss National Science Foundation (P400P2_199285).
To learn more about DRI’s Ice Core Laboratory, please visit: https://www.dri.edu/labs/trace-chemistry-laboratory/.
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About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Sep 9, 2021 | News releases, Research findings
Study Shows A Recent Reversal in the Response of Western Greenland’s Ice Caps to Climate Change
Climate Change
Polar Research
Ice Cores
Above: A wide view of the Nuussuaq Peninsula in West Greenland. Project collaborators investigate an ice core extracted from this region for signs of change and response to past periods of warming.
Credit: Sarah Das © Woods Hole Oceanographic Institution
Research suggests some ice caps grew during past periods of warming
Although a warming climate is leading to rapid melting of the ice caps and glaciers along Greenland’s coastline, ice caps in this region sometimes grew during past periods of warming, according to new research published today in Nature Geoscience. The study team included Joseph McConnell, Nathan Chellman, and Monica Arienzo of DRI, who analyzed a 140 m ice core from an ice cap on Greenland’s Nuussuaq Peninsula at DRI’s Ice Core Laboratory in Reno, Nevada.
“The use of records from Greenland’s coastal ice caps in climate change research has been hampered by difficulties in creating chronologies for ice-core measurements,” said McConnell. “Here we used a novel approach based on synchronizing detailed measurements of heavy metals in an array of Greenland ice cores.”
“This allowed creation of a tightly constrained chronology in a coastal core for the first time, and it was this chronology that underpinned this climate study,” Chellman added.
The analysis was done using DRI’s unique continuous ice core analytical system, which was developed in McConnell’s lab and funded by grants from the National Science Foundation during the past 15 years.
The full news release from Woods Hole Oceanographic Institution is below.
Ice capped and snow-covered mountains of coastal west Greenland. (Apr. 2015)
Credit: Matthew Osman © Woods Hole Oceanographic Institution
News release reposted from Woods Hole Oceanographic Institution:
Woods Hole, Mass. (September 9, 2021) – Greenland may be best known for its enormous continental scale ice sheet that soars up to 3,000 meters above sea level, whose rapid melting is a leading contributor to global sea level rise. But surrounding this massive ice sheet, which covers 79% of the world’s largest island, is Greenland’s rugged coastline dotted with ice capped mountainous peaks. These peripheral glaciers and ice caps are now also undergoing severe melting due to anthropogenic (human-caused) warming. However, climate warming and the loss of these ice caps may not have always gone hand-in-hand.
New collaborative research from the Woods Hole Oceanographic Institution and five partner institutions (University of Arizona, University of Washington, Pennsylvania State University, Desert Research Institute and University of Bergen), published today in Nature Geoscience, reveals that during past periods glaciers and ice caps in coastal west Greenland experienced climate conditions much different than the interior of Greenland. Over the past 2,000 years, these ice caps endured periods of warming during which they grew larger rather than shrinking.
This novel study breaks down the climate history displayed in a core taken from an ice cap off Greenland’s western coast. According to the study’s researchers, while ice core drilling has been ongoing in Greenland since the mid-20th century, coastal ice core studies remain extremely limited, and these new findings are providing a new perspective on climate change compared to what scientists previously understood by using ice cores from the interior portions of the Greenland ice sheet alone.
“Glaciers and ice caps are unique high-resolution repositories of Earth’s climate history, and ice core analysis allows scientists to examine how environmental changes – like shifts in precipitation patterns and global warming – affect rates of snowfall, melting, and in turn influence ice cap growth and retreat,” said Sarah Das, Associate Scientist of Geology and Geophysics at WHOI. “Looking at differences in climate change recorded across several ice core records allows us to compare and contrast the climate history and ice response across different regions of the Arctic.” However, during the course of this study, it also became clear that many of these coastal ice caps are now melting so substantially that these incredible archives are in great peril of disappearing forever.
The research team on the ground of a coastal West Greenland ice cap, preparing to extract and examine ice cores.
Credit: Sarah Das © Woods Hole Oceanographic Institution
Due to the challenging nature of studying and accessing these ice caps, this team was the first to do such work, centering their study, which began in 2015, around a core collected from the Nuussuaq Peninsula in Greenland. This single core offers insight into how coastal climate conditions and ice cap changes covaried during the last 2,000 years, due to tracked changes in its chemical composition and the amount of snowfall archived year after year in the core. Through their analysis, investigators found that during periods of past warming, ice caps were growing rather than melting, contradicting what we see in the present day.
“Currently, we know Greenland’s ice caps are melting due to warming, further contributing to sea level rise. But, we have yet to explore how these ice caps have changed in the past due to changes in climate,” said Matthew Osman, postdoctoral research associate at the University of Arizona and a 2019 graduate of the MIT-WHOI Joint program. “The findings of this study were a surprise because we see that there is an ongoing shift in the fundamental response of these ice caps to climate: today, they’re disappearing, but in the past, within small degrees of warming, they actually tended to grow.”
According to Das and Osman, this phenomenon happens because of a “tug-of-war” between what causes an ice cap to grow (increased precipitation) or recede (increased melting) during periods of warming. Today, scientists observe melting rates that are outpacing the rate of annual snowfall atop ice caps. However, in past centuries these ice caps would expand due to increased levels of precipitation brought about by warmer temperatures. The difference between the past and present is the severity of modern anthropogenic warming.
The team gathered this data by drilling through an ice cap on top of one of the higher peaks of the Nuussuaq Peninsula. The entire core, about 140 meters in length, took about a week to retrieve. They then brought the meter-long pieces of core to the National Science Foundation Ice Core Facility in Denver, Colorado, and stored at -20 degrees Celsius. The core pieces were then analyzed by their layers for melt features and trace chemistry at the Desert Research Institute in Reno, Nevada. By looking at different properties of the core’s chemical content, such as parts per billion of lead and sulfur, investigators were able to accurately date the core by combining these measurements with a model of past glacier flow.
“These model estimates of ice cap flow, coupled with the actual ages that we have from this high precision chemistry, help us outline changes in ice cap growth over time. This method provides a new way of understanding past ice cap changes and how that is correlated with climate,” said Das. “Because we’re collecting a climate record from the coast, we’re able to document for the first time that there were these large shifts in temperature, snowfall and melt over the last 2,000 years, showing much more variability than is observed in records from the interior of Greenland,” Das added.
“Our findings should urge researchers to return to these remaining ice caps and collect new climate records while they still exist,” added Osman.
The research team on the ground of a coastal West Greenland ice cap, preparing to extract and examine ice cores.
Credit: Sarah Das © Woods Hole Oceanographic Institution
Additional collaborators and institutions:
- Benjamin Smith, University of Washington
- Luke Trusel, Pennsylvania State University
- Joseph McConnell, Desert Research Institute
- Nathan Chellman, Desert Research Institute
- Monica Arienzo, Desert Research Institute
- Harold Sodemann, University of Bergen and Bjerknes Centre for Climate Research
This research is funded by the National Science Foundation (NSF), with further support from the U.S. Department of Defense National Defense Science and Engineering Graduate Fellowship; and an Ocean Outlook Fellowship to the Bjerknes Centre for Climate Research; the National Infrastructure for High Performance Computing and Data Storage in Norway; Norwegian Research Council; and Air Greenland.
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About Woods Hole Oceanographic Institution
The Woods Hole Oceanographic Institution (WHOI) is a private, non-profit organization on Cape Cod, Massachusetts, dedicated to marine research, engineering, and higher education. Established in 1930, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate an understanding of the ocean’s role in the changing global environment. WHOI’s pioneering discoveries stem from an ideal combination of science and engineering—one that has made it one of the most trusted and technically advanced leaders in basic and applied ocean research and exploration anywhere. WHOI is known for its multidisciplinary approach, superior ship operations, and unparalleled deep-sea robotics capabilities. We play a leading role in ocean observation and operate the most extensive suite of data-gathering platforms in the world. Top scientists, engineers, and students collaborate on more than 800 concurrent projects worldwide—both above and below the waves—pushing the boundaries of knowledge and possibility. For more information, please visit www.whoi.edu
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Aug 17, 2021 | News releases, Research findings
Photo credit: Flickr photo by Fvanrenterghem. Shared under Creative Commons license 2.0.
DRI Research Highlight
Victoria, Australia is already one of the most bushfire-prone areas in the world, and the number of high-risk days may triple by the end of the century, according to a new study in the International Journal of Wildland Fire. The study team included Tim Brown, Ph.D., research professor of climatology and director of the Western Regional Climate Center at the Desert Research Institute (DRI) in Reno, as well as scientists from Australia and other parts of the US. Brown contributed to the success of the project by collecting information on user needs, overseeing the creation of the historical dataset used in the analysis, and co-developing the methodology used to statistically downscale climate models. He also contributed to results analysis and co-authored the paper.
The full study, Downscaled GCM climate projections of fire weather over Victoria, Australia. Part 2*: a multi-model ensemble of 21st century trends, is available from the International Journal of Wildland Fire : https://www.publish.csiro.au/wf/WF20175
The full news release from CFA is below.
High-risk Bushfire Days Set to Soar This Century
Reposted from CFA
The number of high-risk bushfire days could triple in some parts of Victoria by the end of the century, according to new climate research by CFA and international research bodies.
The research, published this month in the International Journal of Wildland Fire, found that under different emissions scenarios both mean and extreme fire danger are expected to increase in Victoria.
Statewide, research modeling indicates a 10 to 20 percent increase in extreme Forest Fire Danger Index, with the greatest change projected in the northwest region.
However, the greatest relative change in the number of ‘Very High’ days per year will be in central and eastern parts of the state where there is a projected doubling and tripling, respectively in the number of ‘Very High’ days. Report co-author, CFA Manager Research and Development Dr. Sarah Harris, said scenarios used in the research show increased temperature, caused by human-induced climate change, to be the main driver of heightened fire danger.
“Changes in temperature, humidity, and rainfall during spring and early summer mean the fire season will continue to start earlier and run longer. As a flow-on effect, springtime opportunities for prescribed burning could reduce,” she said.
CFA Chief Officer Jason Heffernan said he was proud of CFA’s robust research program, which he said brought further understanding of the impacts of climate change in the context of firefighting.
“As firefighters, we see the effects of these longer and more severe fire seasons and it’s important that we turn our minds towards what firefighting looks like in the not-too-distant future,” he said.
“CFA is undertaking work to identify challenges brought on by climate change and increased fire risk, and ways to solve them through adaptation and mitigation.
“CFA also proudly works to reduce our own greenhouse emissions, through initiatives such as increasing our use of rooftop solar and the number of hybrid vehicles in the fleet.”
CFA Manager Research and Development Sarah Harris co-authored the research with researchers Scott Clark (School of Earth, Atmosphere and Environment, Monash University), Timothy Brown (Desert Research Institute in Nevada, USA), Graham Mills (Monash University) and John T. Abatzoglou (School of Engineering, University of California).
The research was funded through Safer Together, a Victorian approach to reducing the risks of bushfire through fire and land agencies such as CFA, Forest Fire Management Victoria and Parks Victoria working together with communities, combining in-depth local knowledge with the latest science and technology to reduce bushfire risk on both public and private land.
Forest Fire Management Victoria Chief Fire Officer Chris Hardman said partnerships with community and agencies such as CFA and FRV help ensure we are unified in emergency preparedness and response to keep the community and environment safe.
“We know that Victoria is one of the most bushfire-prone areas in the world. Climate change is increasing the risk bushfires pose to our communities, our critical infrastructure, and our environment,” he said.
“That’s why our strategic approach to managing bushfire risk is based on the best evidence available, such as this research.
“We have a 365-day approach to fuel management, more mechanical treatment, and increasing capacity to contain bushfires at first attack. We are also prioritizing empowering Traditional Owners to lead self-determined cultural fire practices on country.”
Jul 20, 2021 | News releases, Research findings
DRI Research Highlight
Mercury is deposited from the atmosphere into forests worldwide in greater quantities than previously thought, according to new research in the journal PNAS led by former Desert Research Institute (DRI) scientist Daniel Obrist (currently with University of Massachusets, Lowell) and a team that included Hans Moosmüller of DRI in Reno. Moosmüller contributed analytical tools for the measurement of mercury fluxes in this study, and also participated in writing the paper. The full news release from UMass Lowell is below.
The full study, Previously unaccounted atmospheric mercury deposition in a midlatitude deciduous forest, is available from PNAS.
Study Shows Forests Play Grater Role in Depositing Toxic Mercury Across the Globe
Reposted from UMass Lowell
LOWELL, Mass. – Researchers led by a UMass Lowell environmental science professor say mercury measurements in a Massachusetts forest indicate the toxic element is deposited in forests across the globe in much greater quantities than previously understood.
The team’s results underscore concern for the health and well-being of people, wildlife and waterways, according to Prof. Daniel Obrist, as mercury accumulating in forests ultimately runs off into streams and rivers, ending up in lakes and oceans.
Mercury is a highly toxic pollutant that threatens fish, birds, mammals and humans. Hundreds of tons of it are released into the atmosphere each year by coal-burning power plants, as well as through gold mining and other industrial processes, and the pollutant is distributed by winds and currents across the globe. Long-term exposure to mercury, or consuming food containing high levels of the pollutant, can lead to reproductive, immune, neurological and cardiovascular problems, according to Obrist, chair of UMass Lowell’s Department of Environmental, Earth and Atmospheric Sciences.
Forests constitute the world’s most abundant, productive and widespread ecosystems on land, according to Obrist, who said the study is the first that examines a full picture of how mercury in the atmosphere is deposited at any rural forest in the world, including the deposition of mercury in its gaseous form, which most previous studies do not address.
“Trees take up gaseous mercury from the atmosphere through their leaves and as plants shed their leaves or die off, they basically transfer that atmospheric mercury to the ecosystems,” he said.
The results of the project, which is supported by a three-year, $873,000 grant from the National Science Foundation (NSF), were published this week in an issue of the Proceedings of the National Academy of Sciences. UMass Lowell student Eric Roy, a double-major in meteorology and mathematics from Lowell, is among the study’s co-authors.
For the past 16 months, the team has measured how mercury in the atmosphere gets deposited at Harvard Forest in Petersham, a nearly 4,000-acre site that includes hardwood deciduous broadleaf trees such as red oak and red maple that shed their leaves every year. A set of measurement systems placed at various heights on the forest’s 100-foot-tall research tower assessed the site’s gaseous mercury deposition from the tree canopy to the forest floor.
“Seventy-six percent of the mercury deposition at this forest comes from gaseous atmospheric mercury. It’s five times greater than mercury deposited by rain and snow and three times greater than mercury that gets deposited through litterfall, which is mercury transferred by leaves falling to the ground and which has previously been used by other researchers as a proxy for estimating gaseous mercury deposition in forests,” Obrist said.
“Our study suggests that mercury loading in forests has been underestimated by a factor of about two and that forests worldwide may be a much larger global absorber and collector of gaseous mercury than currently assumed. This larger-than-anticipated accumulation may explain surprisingly high mercury levels observed in soils across rural forests,” he said.
Plants seem to dominate as a source of mercury on land, accounting for 54 to 94 percent of the deposits in soils across North America. The total global amount of mercury deposited to land currently is estimated at about 1,500 to 1,800 metric tons per year, but it may be more than double if other forests show similar levels of deposition, according to Obrist.
The researchers are continuing their work at a second forest in Howland in northern Maine. Howland Forest, a nearly 600-acre research site full of evergreens that retain their leaves year-round, offers a distinctly different habitat than the deciduous forest in Petersham. Assessing both forests will allow researchers to examine differences in mercury accumulation between different forest types, Obrist said.
The work is providing a hands-on research experience for Roy, a UMass Lowell Honors College student who was invited to become a member of the university’s Immersive Scholar program in 2019. The initiative enables first-year students with outstanding academic credentials to participate in lab work and research right from the start of their academic studies.
“It’s really exciting to be a co-author,” Roy said. “This study allowed us to quantify how much mercury is being accumulated in this type of forest. Modelers can use these results to improve their understanding of how mercury cycles through the environment on a global scale and how that might change in the future.”
Roy helped analyze the data collected in the field.
“Eric’s contributions to the study are tremendous. It’s not very common for an undergrad to play such an important role in a major, federally funded research project,” Obrist said. “His work is really impressive and he has become more and more active in data analysis and doing complex flux calculations and data processing. He really earned himself second author position in the paper in the Proceedings of the National Academy of Sciences.”
Other contributors to the study include Asst. Prof. Róisín Commane of Columbia University; students and postdoctoral researchers from UMass Lowell and Columbia University; and collaborators from Harvard University; the Desert Research Institute in Reno, Nevada; and the Northwest Institute of Eco-Environment and Resources and the University of the Chinese Academy of Sciences in Lanzhou. Additional research support was provided by the U.S. Department of Energy.
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UMass Lowell is a national research university offering its more than 18,000 students bachelor’s, master’s and doctoral degrees in business, education, engineering, fine arts, health, humanities, sciences and social sciences. UMass Lowell delivers high-quality educational programs and personal attention from leading faculty and staff, all of which prepare graduates to be leaders in their communities and around the globe. www.uml.edu
Jul 15, 2021 | News releases, Research findings
Wildfire Smoke Exposure Linked to Increased Risk of Contracting COVID-19
July 15, 2021
RENO, NEV.
By Kelsey Fitzgerald
Wildfire Smoke
COVID-19
Health
Above: Wildfire smoke has been linked to increased risk of contracting COVID-19, according to the results of a new study.
Credit: U.S. Department of Agriculture (public domain image)
A new DRI-led study finds a 17.7 percent rise in COVID-19 cases after a prolonged 2020 wildfire smoke event in Reno, Nev.
Wildfire smoke may greatly increase susceptibility to SARS-CoV-2, the virus that causes COVID-19, according to new research from the Center for Genomic Medicine at the Desert Research Institute (DRI), Washoe County Health District (WCHD), and Renown Health (Renown) in Reno, Nev.
In a study published earlier this week in the Journal of Exposure Science and Environmental Epidemiology, the DRI-led research team set out to examine whether smoke from 2020 wildfires in the Western U.S. was associated with an increase in SARS-CoV-2 infections in Reno.
To explore this, the study team used models to analyze the relationship between fine particulate matter (PM 2.5) from wildfire smoke and SARS-CoV-2 test positivity rate data from Renown Health, a large, integrated healthcare network serving Nevada, Lake Tahoe, and northeast California. According to their results, PM 2.5 from wildfire smoke was responsible for a 17.7 percent increase in the number of COVID-19 cases that occurred during a period of prolonged smoke that took place between Aug. 16 and Oct. 10, 2020.
“Our results showed a substantial increase in the COVID-19 positivity rate in Reno during a time when we were affected by heavy wildfire smoke from California wildfires,” said Daniel Kiser, M.S., co-lead author of the study and assistant research scientist of data science at DRI. “This is important to be aware of as we are already confronting heavy wildfire smoke from the Beckwourth Complex fire and with COVID-19 cases again rising in Nevada and other parts of the Western U.S.”
Wildfire smoke may greatly increase susceptibility to SARS-CoV-2, the virus that causes COVID-19, according to new research from the Center for Genomic Medicine at the Desert Research Institute, Washoe County Health District, and Renown Health in Reno, Nev.
The full text of the study, “SARS-CoV-2 test positivity rate in Reno, Nevada: association with PM2.5 during the 2020 wildfire smoke events in the western United States,” is available from the Journal of Exposure Science and Environmental Epidemiology: https://www.nature.com/articles/s41370-021-00366-w
Reno, located in Washoe County (population 450,000) of northern Nevada, was exposed to higher concentrations of PM2.5 for longer periods of time in 2020 than other nearby metropolitan areas, including San Francisco. Reno experienced 43 days of elevated PM2.5 during the study period, as opposed to 26 days in the San Francisco Bay Area.
“We had a unique situation here in Reno last year where we were exposed to wildfire smoke more often than many other areas, including the Bay Area,” said Gai Elhanan, M.D., co-lead author of the study and associate research scientist of computer science at DRI. “We are located in an intermountain valley that restricts the dispersion of pollutants and possibly increases the magnitude of exposure, which makes it even more important for us to understand smoke impacts on human health.”
Kiser’s and Elhanan’s new research builds upon past work of studies in San Francisco and Orange County by controlling for additional variables such as the general prevalence of the virus, air temperature, and the number of tests administered, in a location that was heavily impacted by wildfire smoke.
“We believe that our study greatly strengthens the evidence that wildfire smoke can enhance the spread of SARS-CoV-2,” said Elhanan. “We would love public health officials across the U.S. to be a lot more aware of this because there are things we can do in terms of public preparedness in the community to allow people to escape smoke during wildfire events.”
More information:
Additional study authors include William Metcalf (DRI), Brendan Schnieder (WCHD), and Joseph Grzymski, a corresponding author (DRI/Renown). This research was funded by Renown Health and the Nevada Governor’s Office of Economic Development Coronavirus Relief Fund.
The full text of the study, “SARS-CoV-2 test positivity rate in Reno, Nevada: association with PM2.5 during the 2020 wildfire smoke events in the western United States,” is available from the Journal of Exposure Science and Environmental Epidemiology: https://www.nature.com/articles/s41370-021-00366-w
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About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
About Renown Health
Renown Health is the region’s largest, local not-for-profit integrated healthcare network serving Nevada, Lake Tahoe, and northeast California. With a diverse workforce of more than 7,000 employees, Renown has fostered a longstanding culture of excellence, determination, and innovation. The organization comprises a trauma center, two acute care hospitals, a children’s hospital, a rehabilitation hospital, a medical group and urgent care network, and the region’s largest, locally owned not-for-profit insurance company, Hometown Health. Renown is currently enrolling participants in the world’s largest community-based genetic population health study, the Healthy Nevada Project®. For more information, visit renown.org.
About Washoe County Health District Air Quality Management Division –
The Air Quality Management Division (AQMD) implements clean air solutions that protect the quality of life for the citizens of Reno, Sparks, and Washoe County through community partnerships along with programs and services such as air monitoring, permitting and compliance, planning, and public education. To learn more, please visit OurCleanAir.com.
Media Contact:
Jul 8, 2021 | News releases, Research findings
Photo caption: Scientist conducts a Secchi disk measurement at Lake Tahoe. Credit: Brant Allen/UC Davis TERC. This news release was written by the UC Davis News and Media Relations/Tahoe Regional Planning Agency.
Lake Tahoe, CA/NV (July 8, 2021) – Lake Tahoe’s water clarity measurements, which are indicators of the health of the watershed, averaged 62.9 feet through 2020, the UC Davis Tahoe Environmental Research Center and the Tahoe Regional Planning Agency announced today.
Lake Tahoe’s clarity peaked in February 2020 when it was deeper than 80 feet. It was at its lowest in mid-May when it measured at slightly more than 50 feet. These readings were within the average range of the last decade. Average clarity in 2020 was just slightly better than the previous year’s average of 62.7 feet.
Clarity has been measured by UC Davis researchers since the 1960s as the depth to which a 10-inch white disk, called a Secchi disk, remains visible when lowered through the water. Because lake clarity measurements vary from day to day and year to year, managers and scientists remain focused on long-term trends as an indicator of the lake’s health.
Measurements show Lake Tahoe’s annual clarity has plateaued over the past 20 years. Despite this progress, summer clarity continues to decline by over a half-foot per year.
“While there is a good understanding of how fine clay particles and tiny algal cells reduce clarity, the biggest challenges are in reducing their presence in the surface water,” said Geoffrey Schladow, director of the UC Davis Tahoe Environmental Research Center. “Here climate change, and in particular the warming of the surface water, is exerting an undue influence.”
A recent review of clarity data by the Tahoe Science Advisory Council reaffirmed the understanding of main drivers of clarity loss. The council commissioned a panel of scientists from regional academic and government research institutions, which concluded that fine sediment particles and algae continue to be the dominant variables affecting Tahoe’s clarity. They recommended that water quality agencies continue to focus on reducing fine sediment and nutrient loads.
Past UC Davis research and the council’s report pointed to several other factors affecting Tahoe’s famed clarity. Climate change is altering precipitation and snowmelt patterns and increasing the temperature of the lake and impeding deep lake mixing. Such mixing in late winter can bring cold, clear water up from deep in the lake, which improves clarity. In 2020, the mixing was extremely shallow and contributed to the lack of improvement.
“Adaptive management is crucial when confronting evolving threats like climate change, invasive species, and expanding visitation rates in the Tahoe Basin, but it is an approach that requires targeted data to assess response to changing conditions and management actions,” said Alan Heyvaert, past Tahoe Science Advisory Council co-chair and Desert Research Institute associate research professor. “This council report demonstrates the value of continued investment and innovation in sustained monitoring and assessment at Tahoe.”
How is clarity measured and why?
Lake Tahoe is known around the world for its water clarity and cobalt blue color. Historically, clarity averaged about 100 feet. A development boom in the mid-20th century brought about unintended environmental impacts, including reduction of the lake’s pristine clarity. For decades, researchers have been documenting changes in the lake, and the research has informed policymakers and stakeholders on management strategies to protect the lake and stabilize its decline in clarity.
In 2020, UC Davis scientists took 27 individual readings at Lake Tahoe’s long-term index station. Using technology beyond the Secchi disk, researchers continue to refine their understanding of lake physics and ecology to determine the evolving causes of clarity change.
The states of California and Nevada, which share Lake Tahoe, are actively working to restore average lake clarity to its historic 100 feet. Under the Clean Water Act, the Lake Tahoe Total Maximum Daily Load is a science-based plan to reduce the amount of fine sediment and nutrients entering the lake by reducing pollution through improved roadway maintenance and erosion control on roadways and private properties.
More than 80 organizations, including government agencies, nonprofits, and research institutions, are working collaboratively with scientists to improve Lake Tahoe’s water clarity and ecological health under the Lake Tahoe Environmental Improvement Program, or EIP, which is one of the most comprehensive, landscape-scale restoration programs in the nation.
“Regaining Lake Tahoe’s water clarity is a commitment we all share, and together we are making a difference,” said Joanne S. Marchetta, executive director of the Tahoe Regional Planning Agency. “While the long‐term clarity trend shows we are on the right track, we need to remain vigilant about restoration while we look to understand more about the role climate change and other threats are playing.”
Media Resources
Media Contacts:
- Geoffrey Schladow, UC Davis Tahoe Environmental Research Center, 530-902-2272, gschladow@ucdavis.edu
- Robert Larsen, Tahoe Science Advisory Council, 916-402-7508, Robert.Larsen@resources.ca.gov
- Kat Kerlin UC Davis News and Media Relations, 530-750-9195, kekerlin@ucdavis.edu
- Jeff Cowen, TRPA Public Information Officer, 775-589-5278, jcowen@trpa.gov
Additional Resources:
May 28, 2021 | News releases, Research findings
DRI Ice Core Lab Data Shows Magnitude of Historic Fire Activity in Southern Hemisphere
Ice Cores
Fire Activity
Climate Change
Above: Smoke from human-caused wildfires on the Patagonian steppe are trapped in Antarctic ice.
Credit: Kathy Kasic/Brett Kuxhausen, Montana State University.
A new study in Science Advances features ice core data from the DRI Ice Core Laboratory and research by Nathan Chellman, Ph.D., Monica Arienzo, Ph.D., and Joe McConnell, Ph.D.
Fire emissions in the Southern Hemisphere may have been much higher during pre-industrial times than in the present day, according to new research from an international team of scientists including Nathan Chellman, Ph.D., Monica Arienzo, Ph.D., and Joe McConnell, Ph.D., of the Desert Research Institute (DRI) in Reno.
The study, published today in Science Advances, used new ice core data from DRI’s Ice Core Laboratory to document changes in levels of soot from ancient fires and modern fossil fuel combustion during the years 1750 to 2000. Many of the 14 Antarctic ice cores included in the study were obtained through national and international collaborations, and together comprise an unprecedented long-term record of Southern Hemisphere fire activity that provided the foundation for the modeling effort described in the new paper.
All of the ice cores were analyzed using a specialized method for soot measurements in ice that McConnell and his team pioneered at DRI nearly 15 years ago. This method is now widely used in laboratories around the world.
For more information about the DRI Ice Core Laboratory, please visit: https://www.dri.edu/labs/trace-chemistry-laboratory/. The full news release from Harvard University, A fiery past sheds new light on the future of global climate change, is posted below.
Co-author Dr. Robert Mulvaney from the British Antarctic Arctic Survey drilling the James Ross Island core in the Antarctic Peninsula.
The full text of the paper, Improved estimates of preindustrial biomass burning reduce the magnitude of aerosol climate forcing in the Southern Hemisphere, is available from Science Advances: https://advances.sciencemag.org/content/7/22/eabc1379.abstract
A fiery past sheds new light on the future of global climate change
Ice core samples reveal significant smoke aerosols in the pre-industrial Southern Hemisphere
By Leah Burrows, Harvard University
Centuries-old smoke particles preserved in the ice reveal a fiery past in the Southern Hemisphere and shed new light on the future impacts of global climate change, according to new research published in Science Advances.
“Up till now, the magnitude of past fire activity, and thus the amount of smoke in the preindustrial atmosphere, has not been well characterized,” said Pengfei Liu, a former graduate student and postdoctoral fellow at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and first author of the paper. “These results have importance for understanding the evolution of climate change from the 1750s until today, and for predicting future climate.”
One of the biggest uncertainties when it comes to predicting the future impacts of climate change is how fast surface temperatures will rise in response to increases in greenhouse gases. Predicting these temperatures is complicated since it involves the calculation of competing warming and cooling effects in the atmosphere. Greenhouse gases trap heat and warm the planet’s surface while aerosol particles in the atmosphere from volcanoes, fires and other combustion cool the planet by blocking sunlight or seeding cloud cover. Understanding how sensitive surface temperature is to each of these effects and how they interact is critical to predicting the future impact of climate change.
Ancient ice from James Ross Island in the Northern Antarctic Peninsula about to be extracted from the drill barrel.
Many of today’s climate models rely on past levels of greenhouse gasses and aerosols to validate their predictions for the future. But there’s a problem: While pre-industrial levels of greenhouse gasses are well documented, the amount of smoke aerosols in the preindustrial atmosphere is not.
To model smoke in the pre-industrial Southern Hemisphere, the research team looked to Antarctica, where the ice trapped smoke particles emitted from fires in Australia, Africa and South America. Ice core scientists and co-authors of the study, Joseph McConnell and Nathan Chellman from the Desert Research Institute in Nevada, measured soot, a key component of smoke, deposited in an array of 14 ice cores from across the continent, many provided by international collaborators.
“Soot deposited in glacier ice directly reflects past atmospheric concentrations so well-dated ice cores provide the most reliable long-term records,” said McConnell.
What they found was unexpected.
“While most studies have assumed less fire took place in the preindustrial era, the ice cores suggested a much fierier past, at least in the Southern Hemisphere,” said Loretta Mickley, Senior Research Fellow in Chemistry-Climate Interactions at SEAS and senior author of the paper.
To account for these levels of smoke, the researchers ran computer simulations that account for both wildfires and the burning practices of indigenous people.
“The computer simulations of fire show that the atmosphere of the Southern Hemisphere could have been very smoky in the century before the Industrial Revolution. Soot concentrations in the atmosphere were up to four times greater than previous studies suggested. Most of this was caused by widespread and regular burning practiced by indigenous peoples in the pre-colonial period,” said Jed Kaplan, Associate Professor at the University of Hong Kong and co-author of the study.
Drilling ice cores in East Antarctica as part of the Norwegian-U.S. International IPY Scientific Traverse of East Antarctica.
This result agrees with the ice core records that also show that soot was abundant before the start of the industrial era and has remained relatively constant through the 20th century. The modeling suggests that as land-use changes decreased fire activity, emissions from industry increased.
What does this finding mean for future surface temperatures?
By underestimating the cooling effect of smoke particles in the pre-industrial world, climate models might have overestimated the warming effect of carbon dioxide and other greenhouse gasses in order to account for the observed increases in surface temperatures.
“Climate scientists have known that the most recent generation of climate models have been over-estimating surface temperature sensitivity to greenhouse gasses, but we haven’t known why or by how much,” said Liu. “This research offers a possible explanation.”
“Clearly the world is warming but the key question is how fast will it warm as greenhouse gas emissions continue to rise. This research allows us to refine our predictions moving forward,” said Mickley.
The research was co-authored by Yang Li, Monica Arienzo, John Kodros, Jeffrey Pierce, Michael Sigl, Johannes Freitag, Robert Mulvaney, and Mark Curran.
It was funded by the National Science Foundation’s Geosciences Directorate under grants AGS-1702814 and 1702830, with additional support from 0538416, 0538427, and 0839093.
Additional Information:
The full text of the paper, Improved estimates of preindustrial biomass burning reduce the magnitude of aerosol climate forcing in the Southern Hemisphere, is available from Science Advances: https://advances.sciencemag.org/content/7/22/eabc1379.abstract
The news release above was reposted with permission from Harvard University: https://www.seas.harvard.edu/news/2021/05/fiery-past-sheds-new-light-future-global-climate-change.
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About the Desert Research Institute
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policymakers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu
May 25, 2021 | News releases, Research findings
Does Cold Wildfire Smoke Contribute to Water Repellent Soils in Burned Areas?
May 25, 2021
RENO, NEV.
By Kelsey Fitzgerald
Soil Science
Wildfires
Hydrology
Above: After a wildfire, soils in burned areas often become water repellent, leading to increased erosion and flooding after rainfall events. The hillside shown here burned in California’s Loyalton Fire during August 2020.
Credit: Kelsey Fitzgerald/DRI.
A new DRI pilot study finds severe water repellency in sand samples after treatment with both hot and cold smoke.
After a wildfire, soils in burned areas often become water repellent, leading to increased erosion and flooding after rainfall events – a phenomenon that many scientists have attributed to smoke and heat-induced changes in soil chemistry. But this post-fire water repellency may also be caused by wildfire smoke in the absence of heat, according to a new paper from the Desert Research Institute (DRI) in Nevada.
In this pilot study (exploratory research that takes place before a larger-scale study), an interdisciplinary team of scientists led by DRI Associate Research Professor of Atmospheric Science Vera Samburova, Ph.D., exposed samples of clean sand to smoke from burning Jeffrey pine needles and branches in DRI’s combustion chamber, then analyzed the time it took for water droplets placed on the sand surface to be absorbed – a measure of water repellency.
A new pilot study by an interdisciplinary team from DRI exposed samples of clean sand to smoke from burning Jeffrey pine needles and branches, then analyzed the time it took for water droplets placed on the sand surface to be absorbed — a measure of water repellency. After exposure to smoke, water droplets sometimes remained on the sand surface for more than 50 minutes without soaking in.
Credit: Vera Samburova/DRI.
The pilot study investigated the effects of smoke and heat on water repellency of the sand and was the first study to also incorporate an analysis of cold smoke. In the experiments, sand was used in place of soil because it could be cleaned thoroughly and analyzed accurately, and Jeffrey pine for a fuel source because it represents a common wildland fire fuel in the Western U.S.
Before exposure to Jeffrey pine smoke, water droplets placed on the surface of the sand samples were quickly absorbed. But after exposure to smoke, the sand samples showed severe-to-extreme water repellency, in some cases retaining water droplets on the sand surface for more than 50 minutes without soaking in. It made little difference whether or not samples had been exposed to heat and smoke, or just cold smoke.
“The classic explanation for fire-induced water repellency is that it is caused as smoke diffuses under rather hot conditions and settles down into the soils, but our work shows that the smoke does not have to be hot to turn the sand hydrophobic — simply the presence of the chemical substances in the smoke is enough,” Samburova said. “This is something we really need to look deeper into because soil water repellency leads to increases in flooding, erosion, and surface runoff.”
Above, left: Jeffrey pine needles and sticks were used as a fuel source in the new DRI study because Jeffrey pine represents a common wildland fire fuel in the Western U.S.
Credit: Vera Samburova/DRI.
Above, right: Jeffrey pine needles and branches burn inside of the combustion chamber at DRI during a new study that investigated the effects of smoke and heat on water repellent of sand samples.
Credit: Vera Samburova/DRI.
This study built on previously published work by former DRI postdoctoral researcher Rose Shillito, Ph.D., (currently with the U.S. Army Corps of Engineers), Markus Berli, Ph.D., of DRI, and Teamrat Ghezzehei, Ph.D., of University of California, Merced, in which the researchers developed an analytical model for relating soil water repellency to infiltration of water.
“Our earlier paper focused on how fire changes the properties of soils, from a hydrology perspective,” Berli explained. “In our current study, we were interested in learning more about the chemistry behind the process of how soils come to be hydrophobic. We’re bringing together geochemistry and organic geochemistry with soil physics and hydrology to understand the impact of fire-induced water repellency on hydrology.”
The project team is now working on a larger proposal to further investigate questions touched on by this study about the roles of heat and smoke in fire-induced water repellency. Among other things, they would like to know how long soil water repellency lasts after a fire, and gain a better understanding of the detailed processes and mechanisms through which cold smoke affects the soil.
DRI’s combustion chamber, pictured here, is a specialized facility that has been designed and built for the open combustion of solid fuels under controlled conditions. In this experiment, it was used to expose samples of clean sand to Jeffrey pine smoke.
Credit: Kelsey Fitzgerald/DRI.
Gaining a thorough understanding of the process that leads to fire-induced soil water repellency is important because land managers need this information in order to accurately predict where soils are likely to be hydrophobic after a fire, Berli explained.
“We still don’t really understand the processes that lead to this fire-induced soil water repellency,” Berli said. “Depending on what we find, the measures to predict fire-induced water repellency might be different, and this can have a significant impact on how we can predict and prevent flooding or debris flows that happen after a fire.”
“This study was one big step forward, but it highlights the importance of future research on how fires affect soil, because wildfires are affecting thousands and thousands of square kilometers of land each year in the Western U.S., ” Samburova added. “Some of our future goals are to find out how exactly this soil water repellent happens, where it happens and how long it lasts.”
Additional Information:
This study was made possible with support from DRI and the National Science Foundation. Study authors included Vera Samburova, Ph.D., Rose Shillito, Ph.D. (currently with U.S. Army Corps of Engineers), Markus Berli, Ph.D., Andrey Khlystov, Ph.D., and Hans Moosmüller, Ph.D., all from DRI.
The full text of the paper, Effect of Biomass-Burning Emissions on Soil Water Repellency: A Pilot Laboratory Study, is available from Fire: https://www.mdpi.com/2571-6255/4/2/24
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About the Desert Research Institute
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu
May 18, 2021 | News releases, Research findings
Above: DeMMO field team from left to right: Lily Momper, Brittany Kruger, and Caitlin Casar sampling fracture fluids from a DeMMO borehole installation. Credit: Matt Kapust.
Las Vegas, Nev. – Below the Earth’s surface, a zone of life known as the continental deep subsurface is home to large populations of bacteria and archaea, but little is known about how these microbial populations are distributed. To learn whether they are spread evenly across rock surfaces or prefer to colonize specific minerals in the rocks, scientists from Northwestern University and the Desert Research Institute (DRI) went deep inside of a former gold mine in South Dakota and grew biofilms (collections of microorganisms) on rocks. Their results, which published in April in the journal Frontiers in Microbiology, show that the microbes formed “hotspots” around certain minerals in the rocks. Brittany Kruger, Ph.D., Assistant Research Scientist in Biogeochemistry from DRI in Las Vegas, served as field lead for the Northwestern research team at the Sanford Underground Research Facility (SURF), where this study was conducted.
The full text of the paper Rock-Hosted Subsurface Biofilms: Mineral Selectivity Drives Hotspots for Intraterrestrial Life is available from Frontiers in the Environment: https://www.frontiersin.org/articles/10.3389/fmicb.2021.658988/full
The press release below was reposted with permission from Northwestern University in Evanston, IL:
Earth’s crust mineralogy drives hotspots for intraterrestrial life
Northwestern University – Evanston, IL
April 9, 2021 – Below the verdant surface and organic rich soil, life extends kilometers into Earth’s deep rocky crust. The continental deep subsurface is likely one of the largest reservoirs of bacteria and archaea on Earth, many forming biofilms – like a microbial coating of the rock surface. This microbial population survives without light or oxygen and with minimal organic carbon sources, and can get energy by eating or respiring minerals. Distributed throughout the deep subsurface, these biofilms could represent 20-80% of the total bacterial and archaeal biomass in the continental subsurface according to the most recent estimate. But are these microbial populations spread evenly on rock surfaces, or do they prefer to colonize specific minerals in the rocks?
To answer this question, researchers from Northwestern University in Evanston, Illinois, led a study to analyze the growth and distribution of microbial communities in deep continental subsurface settings. This work shows that the host rock mineral composition drives biofilm distribution, producing “hotspots” of microbial life. The study was published in Frontiers in Microbiology.
Hotspots of microbial life
To realize this study, the researchers went 1.5 kilometers below the surface in the Deep Mine Microbial Observatory (DeMMO), housed within a former gold mine now known as the Sanford Underground Research Facility (SURF), located in Lead, South Dakota. There, below-ground, the researchers cultivated biofilms on native rocks rich in iron and sulfur-bearing minerals. After six months, the researchers analyzed the microbial composition and physical characteristics of newly grown biofilms, as well as its distributions using microscopy, spectroscopy and spatial modeling approaches.
The spatial analyses conducted by the researchers revealed hotspots where the biofilm was denser. These hotspots correlate with iron-rich mineral grains in the rocks, highlighting some mineral preferences for biofilm colonization. “Our results demonstrate the strong spatial dependence of biofilm colonization on minerals in rock surfaces. We think that this spatial dependence is due to microbes getting their energy from the minerals they colonize,” explains Caitlin Casar, first author of the study.
Future research
Altogether, these results demonstrate that host rock mineralogy is a key driver of biofilm distribution, which could help improve estimates of the microbial distribution of the Earth’s deep continental subsurface. But leading intraterrestrial studies could also inform other topics. “Our findings could inform the contribution of biofilms to global nutrient cycles, and also have astrobiological implications as these findings provide insight into biomass distributions in a Mars analog system” says Caitlin Casar.
Indeed, extraterrestrial life could exist in similar subsurface environments where the microorganisms are protected from both radiation and extreme temperatures. Mars, for example, has an iron and sulfur-rich composition similar to DeMMO’s rock formations, which we now know are capable of driving the formation of microbial hotspots below-ground.
Apr 15, 2021 | News releases, Research findings
Above: Equipment for subsurface sampling of microbes stands in Death Valley, California. Credit: Duane Moser/DRI.
Las Vegas, Nev. (April 15, 2021) – Although certain microbes have the ability to evolve very quickly, the opposite can also be true, according to new research from an international team of scientists including Duane Moser, Ph.D., Joshua Sackett, Ph.D., and Brittany Kruger, Ph.D. of the Desert Research Institute (DRI) in Las Vegas. The new paper, which was led by scientists from the Bigelow Laboratory for Ocean Sciences and published last week in Nature publishing group’s ISME Journal, identifies a group of microbes from the deepest regions of the continental subsurface biosphere that have been at an evolutionary standstill for approximately 175 million years.
The study used partial genomes of the microbe, Candidatus Desulforudis audaxviator that were collected from deep underground in South Africa, Siberia, and California. Moser contributed the North American samples, which were collected in 2015 at a depth of 752 m (2,467 ft.) during activities of the NASA Astrobiology Institute’s Life Underground project (Jan Amend, USC, PI) from the Death Valley Regional Flow System, a vast fractured rock aquifer that underlies portions of Nevada and Eastern CA. The North America re-discovery of D. audaxviator brings an old story full-circle for Moser in that he also collected the samples from which the organism was originally described from fracture networks as much as 4 – 5 km (2.5 – 3.1 miles) deep in South Africa while a postdoc with TC Onstott at Princeton University in the early 2000s.
The full text of the paper, Evolutionary stasis of a deep subsurface microbial lineage, is available from ISME Journal: https://www.nature.com/articles/s41396-021-00965-3
The press release below is reposted with permission from Bigelow Laboratory for Ocean Sciences.
Living fossils: Microbe discovered in evolutionary stasis for millions of years
BIGELOW LABORATORY FOR OCEAN SCIENCES
It’s like something out of science fiction. Research led by Bigelow Laboratory for Ocean Sciences has revealed that a group of microbes, which feed off chemical reactions triggered by radioactivity, have been at an evolutionary standstill for millions of years. The discovery could have significant implications for biotechnology applications and scientific understanding of microbial evolution.
“This discovery shows that we must be careful when making assumptions about the speed of evolution and how we interpret the tree of life,” said Eric Becraft, the lead author on the paper. “It is possible that some organisms go into an evolutionary full-sprint, while others slow to a crawl, challenging the establishment of reliable molecular timelines.”
Becraft, now an assistant professor of biology at the University of Northern Alabama, completed the research as part of his postdoctoral work at Bigelow Laboratory and recently published it in the Nature publishing group’s ISME Journal.
The microbe, Candidatus Desulforudis audaxviator, was first discovered in 2008 by a team of scientists, led by Tullis Onstott, a co-author on the new study. Found in a South African gold mine almost two miles beneath the Earth’s surface, the microbes acquire the energy they need from chemical reactions caused by the natural radioactive decay in minerals. They inhabit water-filled cavities inside rocks in a completely independent ecosystem, free from reliance on sunlight or any other organisms.
Because of their unique biology and isolation, the authors of the new study wanted to understand how the microbes evolved. They searched other environmental samples from deep underground and discovered Candidatus Desulforudis audaxviator in Siberia and California, as well as in several additional mines in South Africa. Since each environment was chemically different, these discoveries gave the researchers a unique opportunity to look for differences that have emerged between the populations over their millions of years of evolution.
“We wanted to use that information to understand how they evolved and what kind of environmental conditions lead to what kind of genetic adaptations,” said Bigelow Laboratory Senior Research Scientist Ramunas Stepanauskas, the corresponding author on the paper and Becraft’s postdoctoral advisor. “We thought of the microbes as though they were inhabitants of isolated islands, like the finches that Darwin studied in the Galapagos.”
C.D. audaxviator Scanning Electron Micrograph from 3.2 km depth in Driefontein Mine, South Africa. Image courtesy of Gordon Southam and Greg Wanger.
Using advanced tools that allow scientists to read the genetic blueprints of individual cells, the researchers examined the genomes of 126 microbes obtained from three continents. Surprisingly, they all turned out to be almost identical.
“It was shocking,” Stepanauskas said. “They had the same makeup, and so we started scratching our heads.”
Scientists found no evidence that the microbes can travel long distances, survive on the surface, or live long in the presence of oxygen. So, once researchers determined that there was no possibility the samples were cross-contaminated during research, plausible explanations dwindled.
“The best explanation we have at the moment is that these microbes did not change much since their physical locations separated during the breakup of supercontinent Pangaea, about 175 million years ago,” Stepanauskas said. “They appear to be living fossils from those days. That sounds quite crazy and goes against the contemporary understanding of microbial evolution.”
What this means for the pace of microbial evolution, which often happens at a much more accelerated rate, is surprising. Many well-studied bacteria, such as E. coli, have been found to evolve in only a few years in response to environmental changes, such as exposure to antibiotics.
Stepanauskas and his colleagues hypothesize the standstill evolution they discovered is due to the microbe’s powerful protections against mutation, which have essentially locked their genetic code. If the researchers are correct, this would be a rare feature with potentially valuable benefits.
Microbial enzymes that create copies of DNA molecules, called DNA polymerases, are widely used in biotechnology. Enzymes with high fidelity, or the ability to recreate themselves with little differences between the copy and the original, are especially valuable.
“There’s a high demand for DNA polymerases that don’t make many mistakes,” Stepanauskas said. “Such enzymes may be useful for DNA sequencing, diagnostic tests, and gene therapy.”
Beyond potential applications, the results of this study could have far-reaching implications and change the way scientists think about microbial genetics and the pace of their evolution.
“These findings are a powerful reminder that the various microbial branches we observe on the tree of life may differ vastly in the time since their last common ancestor,” Becraft said. “Understanding this is critical to understanding the history of life on Earth.”
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Bigelow Laboratory for Ocean Sciences is an independent, nonprofit research institute located in East Boothbay, Maine. From the Arctic to the Antarctic, Bigelow Laboratory scientists use innovative approaches to study the foundation of global ocean health and unlock its potential to improve the future for all life on the planet. Learn more at bigelow.org, and join the conversation on Facebook, Instagram, and Twitter.
Mar 11, 2021 | News releases, Research findings
Above: WestWide Drought Tracker data for winter 2020-21 show that precipitation levels across California and Nevada have fallen far below normal. Credit: WRCC/DRI.
91 percent of California and 100 percent of Nevada now in drought
Reno, Nev. (Mar 11, 2021) – Drought conditions are intensifying across California and Nevada, with U.S. Drought Monitor showing 91 percent of California and 100 percent of Nevada now in drought, according to a Drought Status Update released this morning by the National Oceanic and Atmospheric Administration (NOAA) National Integrated Drought Information System (NIDIS), the California-Nevada Applications Program (CNAP), and the Western Regional Climate Center at the Desert Research Institute.
The Drought Status Update is issued every two weeks on Drought.gov as part of the California-Nevada Drought Early Warning System and communicates the current state of drought conditions in California and Nevada using information from sources such as the U.S. Drought Monitor, NOAA, CNAP, the Natural Resources Conservation Service (NRCS), the Center for Western Weather and Water Extremes (CW3E), and others.
According to today’s update, California and Nevada remain entrenched in moderate-to-exceptional levels of drought, with precipitation totals and snowpack falling below normal. Although recent spring storms have brought moisture to certain areas of the region, those and other potential spring storms are not expected to significantly improve the drought conditions.
“The chance of getting back to an average snowpack for this winter is looking less and less likely,” said Tamara Wall, Ph.D., Associate Research Professor at DRI and Co-Principal Investigator of the CNAP program. “It is time to really start thinking about the impact that this will have across California and Nevada as we move into the warmer months.”
In Nevada, conditions are especially dire, with 40 percent of the state now classified by the U.S. Drought Monitor as “exceptional drought,” or D4 – more area than at any point during the previous drought of 2012-2016. In the Carson, Truckee, and Walker Basins, reservoir storage is also lower than it was this time last year, all currently at less than 40 percent of capacity.
During the last two weeks, the authors have noted a significant increase in drought impact reports from water utilities to agriculture as it has become clearer that drought is here to stay in California and Nevada and the region’s odds of reaching normal are low.
“Recently, we’ve seen confirmation that any remaining storms won’t bring much drought relief and drought impacts are intensifying and expanding,” said Amanda Sheffield, Ph.D., NOAA NIDIS Regional Drought Information Coordinator for California-Nevada.
Seasonal forecasts predict a continuation of warm, dry conditions over the Great Basin and Southwestern U.S. as we head into spring and early summer. As drought conditions intensify, impacts to agriculture, water supplies, and forests are expected, as well as increased wildfire potential.
“The abnormally dry conditions that we’ve had this winter mean a second dry year for much of California and Nevada, which means that working on our drought preparedness right now is essential,” said Julie Kalansky, CNAP Program Manager, Scripps Institution of Oceanography. “These conditions have potential implications for agriculture, ecosystem health, water supply, and fire potential.”
Additional information:
To view the full Drought Status Update for March 11, 2021, on Drought.gov, please visit: https://www.drought.gov/drought-status-updates/drought-status-update-california-nevada-2
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Feb 22, 2021 | News releases, Research findings
Traditional hydrologic models may misidentify snow as rain, new citizen science data shows
Weather Forecasting
Climate
Citizen Science
Tahoe Rain or Snow weather spotters help reduce inaccuracies in estimating precipitation
Normally, we think of the freezing point of water as 32°F – but in the world of weather forecasting and hydrologic prediction, that isn’t always the case. In the Lake Tahoe region of the Sierra Nevada, the shift from snow to rain during winter storms may actually occur at temperatures closer to 39.5°F, according to new research from the Desert Research Institute (DRI), Lynker Technologies, and citizen scientists from the Tahoe Rain or Snow project.
The new paper, which published this month in Frontiers in Earth Science, used data collected by 200 volunteer weather spotters to identify the temperature cutoff between rain and snow in winter storms that occurred during the 2020 season. Their results have implications for the accuracy of water resources management, weather forecasting, and more.
“Scientists use a temperature threshold to determine where and when a storm will transition from rain to snow, but if that threshold is off, it can affect our predictions of flooding, snow accumulation, and even avalanche formation,” said Keith Jennings, Ph.D., Water Resources Scientist at Lynker Technologies and one of the lead authors on the study.
From a backcountry area near Lake Tahoe, Desert Research Institute scientist Monica Arienzo collects field data from her smartphone for the Tahoe Rain or Snow project. January 2021.
Previous studies have found that thresholds used are particularly problematic in the Sierra Nevada, where a significant proportion of winter precipitation falls near 32°F. When the temperature is near freezing, weather forecasts and hydrologic models have difficulty correctly predicting whether it will be raining or snowing.
Tahoe Rain or Snow was launched in 2019 to take on the challenge of enhancing the prediction of snow accumulation and rainfall that may lead to flooding by making real-time observations of winter weather. The team is comprised of two scientists, one education specialist, and about 200 volunteer weather spotters from the Lake Tahoe and western slope regions of the Sierra Nevada and Truckee Meadows.
“Tahoe Rain or Snow harnesses the power of hundreds of local volunteers. The real-time observations that they share with scientists add an incredible amount of value to the study of hydrology and clarify crucial gaps left by weather models,” said Meghan Collins, M.S., Education Program Manager for DRI and another lead author on the paper.
Above: Desert Research Institute scientist Meghan Collins collects data from her smartphone for the Tahoe Rain or Snow project using the Citizen Science Tahoe app during January 2021.
Credit: DRI (left) and Keith Jennings/Lynker Techologies (right)
In 2020, these citizen scientists submitted over 1,000 timestamped, geotagged observations of precipitation phases through the Citizen Science Tahoe mobile phone app.
Ground-based observations submitted by the Tahoe Rain or Snow team in 2020 showed that a much warmer temperature threshold of 39.5°F for splitting precipitation into rain and snow may be more accurate for our mountain region. In contrast, a 32°F rain-snow temperature threshold would have vastly overpredicted rainfall, leading to pronounced underestimates of snow accumulation. Such model errors can lead to issues in water resources management, travel planning, and avalanche risk prediction.
“Tahoe Rain or Snow citizen scientists across our region open a door to improve our understanding of winter storms”, said Monica Arienzo, Ph.D., Assistant Research Professor of Hydrology at DRI and another lead author on the paper. “Growing our team of volunteer scientists is important given that climate change is causing the proportion of precipitation falling as snow to decrease, and they help enhance the predictions of precipitation that we rely on in the Sierra Nevada and Truckee Meadows.”
Tahoe Rain or Snow is continuing in 2021. To join, text WINTER to 877-909-0798. You will find out how to download the Citizen Science Tahoe app and receive alerts as to good times to send weather observations. Tahoe Rain or Snow particularly needs observations from sparsely populated, remote, or backcountry areas of the Sierra Nevada.
Desert Research Institute scientist Monica Arienzo collects field data from her smartphone for the Tahoe Rain or Snow project. January 2021.
Additional Information:
This study was funded by Nevada NASA EPSCoR Grant 20-23, 19-40.
The full text of the study “Enhancing Engagement of Citizen Scientists to Monitor Precipitation Phase” is available from Frontiers in Environmental Science: https://www.frontiersin.org/articles/10.3389/feart.2021.617594/full
To learn more about the Tahoe Rain or Snow project, please visit: https://www.dri.edu/project/tahoe-rain-or-snow/
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policymakers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Lynker Technologies delivers innovative solutions to support global environmental sustainability and economic prosperity as a trusted partner to governments, communities, research institutions, and industry. We are passionate about what we do and the high value we provide to water resources management, hydrologic science, and conservation across the US and beyond. For more information, please visit https://www.lynker.com/.
Feb 1, 2021 | News releases, Research findings
Photo caption: A monsoon rain event in the East River watershed of Colorado, a pristine, high elevation, snow-dominated headwater basin of the Colorado River. Credit: Xavier Fane.
New study holds implications for future water supply in the Colorado River Basin
Las Vegas, Nev. (Monday, Feb. 1, 2021) – In the summer of 2019, Desert Research Institute (DRI) scientist Rosemary Carroll, Ph.D., waited for the arrival of the North American Monsoon, which normally brings a needed dose of summer moisture to the area where she lives in Crested Butte, Colo. – but for the fourth year in a row, the rains never really came.
“2019 had just a horrendous monsoon,” Carroll said. “Just the weakest monsoon. And we’d had a few years of weak monsoons before that, which had really gotten me wondering, how important is the monsoon to late summer streamflow here in the Upper Colorado River basin? And how do monsoons influence the following year’s streamflow?”
Working in partnership with colleagues David Gochis, Ph.D., of the National Center for Atmospheric Research and Kenneth Williams, Ph.D., of Lawrence Berkeley National Laboratory, Carroll set out to explore the importance of monsoon rain in streamflow generation in a Colorado River headwater basin.
The team’s findings, which are published in a new paper in Geophysical Research Letters, point to both the importance of monsoon rains in maintaining the Upper Colorado River’s water supply and the diminishing ability of monsoons to replenish summer streamflow in a warmer future with less snow accumulation.
Their study focuses on the East River watershed, a pristine, high elevation, snow-dominated headwater basin of the Colorado River and part of the Watershed Function Scientific Focus Area (SFA) program that is exploring how disturbances in mountain systems – such as floods, drought, changing snowpack and earlier snowmelt – impact the downstream delivery of water, nutrients, carbon, and metals.
Using a hydrologic model and multiple decades of climate data from the East River watershed, Carroll and her colleagues found that monsoon rains normally deliver about 18 percent of the basin’s water and produce about 10 percent of the annual streamflow, with streamflow generated primarily in the higher elevations of the basin.
“The amount of streamflow produced by monsoons, while not geographically extensive, is actually somewhat substantial,” Carroll said. “It was larger than I thought it would be. That doesn’t mean all of that water gets to a reservoir – some likely is used by riparian vegetation or irrigation, but it still does go to meet some need within the basin.”
Desert Research Institute scientist Rosemary Carroll measures stream discharge in the East River, Colorado. Credit: Kenneth H. Williams.
Next, the team explored the ability of these summer rains to produce streamflow during cool years with high snow accumulation, and during warm years with less snow accumulation. During cool years with more snow, soil moisture levels were higher going into summer, and greater streamflow was generated by the monsoon rains. During warmer years with low snowpack, dry soils absorbed much of the monsoonal rains, and less runoff made it to the streams.
“You can think of the soil zone as a sponge that needs to fill up before it can allow water to move through it,” Carroll said. “So, if it’s already depleted because you had low snowpack, the monsoon then has to fill it back up, and that decreases the amount of water you actually get in the river.”
As the climate warms, snowpack in the Rocky Mountains and other mountain systems is expected to decline, leading to reduced streamflow. Rising temperatures also lead to increased soil evaporation and increased water use by plants. According to the results of Carroll’s study, these changes will reduce the ability of water from the monsoon to make it to the river as streamflow.
“Our results indicate that as we move toward a climate that is warmer and our snowpack decreases, the ability of monsoon rain to buffer these losses in streamflow is also going to go down,” Carroll said. “So, the monsoon is not some silver bullet that is going to help mitigate those changes.”
The Colorado River is a critically important resource for people living in Southern Nevada, where it accounts for about 90 percent of the water supply. Although runoff from winter snowpack provides a much larger proportion of streamflow each year than the monsoons, the monsoonal moisture is important to both ecosystems and people in part because it arrives at a different time of year. And in a system like the Colorado River, where every drop of water is allocated, if monsoon rains do not arrive, it creates a shortage somewhere downstream.
“In terms of water resources, if monsoon rains are useful and contribute to late-season streamflow, then the loss of that water obviously has implications for the ecology of these systems,” Carroll said. “This water is really important in supporting aquatic habitat there. But it’s also really important for human use. If any amount of water that we rely on isn’t there, then something has to give. The Upper Basin will have to consider how they are going to manage their water to meet those downstream obligations.”
Additional information:
The full text of the study, Efficiency of the Summer Monsoon in Generating Streamflow Within a Snow‐Dominated Headwater Basin of the Colorado River, is available from Geophysical Research Letters: https://doi.org/10.1029/2020GL090856
For more information on Rosemary Carroll, please visit: https://www.dri.edu/directory/rosemary-carroll/
For more information on the Watershed Function Scientific Focus Area (SFA) program, please visit: http://watershed.lbl.gov/
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Dec 15, 2020 | News releases, Research findings
Together, will test over 30,000 qualifying study participants by 2023 for risk of cirrhosis and liver-related illnesses
RENO, Nev. (Dec. 15, 2020) – Renown Institute for Health (IHI) announced today that the organization and Gilead Sciences, Inc. will be joining forces with Siemens Healthineers to offer the Enhanced Liver Fibrosis (ELF™) Test to people with risks for nonalcoholic steatohepatitis (NASH) enrolled in the Healthy Nevada Project (HNP).
The ELF Test will help identify people most at risk for progressing to cirrhosis and liver-related outcomes and allow healthcare providers to intervene before irreparable damage occurs. This noninvasive blood test uses three serum biomarkers to create an ELF score from a predefined algorithm, which can be used by doctors to help evaluate if a patient requires increased medical care and monitoring for their condition.
Nonalcoholic fatty liver disease (NAFLD), which includes NASH, is prevalent in Nevada and under-diagnosed, likely affecting more than 500,000 adult Nevadans. If undetected and untreated, NASH can result in liver cirrhosis and may require liver transplantation or lead to death. There are more than 12,000 people on a waitlist for liver transplantation in the US and this number continues to rise due to the increasing prevalence of NAFLD.
“Thanks to important data collected through our Nonalcoholic Steatohepatitis Liver Disease Genome Atlas study, we now know that NASH is prevalent in the state of Nevada,” said Tony Slonim, M.D., DrPH, FACHE, president and CEO of Renown Health. “We are proud to expand our partnership with Gilead and begin working with Siemens Healthineers to improve health of those with liver disease and to take early detection one step further by offering Enhanced Liver Fibrosis, ELF testing for patients of Renown Health. This test provides our team of highly-skilled physicians an advanced, noninvasive method to actively assess dynamic liver fibrosis in study participants and intervene whenever necessary, contributing to a healthier Nevada.”
“Gilead believes that noninvasive tests, including the ELF Test, will help improve the experience of people living with NASH. These tests may help to diagnose liver disease, monitor disease progression and evaluate responses to treatment without the requirement for liver biopsy,” said Rob Myers, MD, Vice President, Liver Fibrosis Clinical Research at Gilead Sciences. “The ELF Test has proven itself to be a valuable tool in NASH management and we hope this partnership will further support its use in routine care.”
“We are very pleased that NASH patients in the Healthy Nevada Project ® now have access to the ELF Test which offers clinically useful prognostic information for their condition with the convenience of a simple blood test. Using our advanced laboratory expertise together with Renown IHI and Gilead, we can work toward better understanding of NASH and liver disease in a representative patient population,” said Sebastian Kronmueller, Head of Molecular Diagnostics at Siemens Healthineers.
“We launched the Healthy Nevada Project ® to help people understand more about their health, to identify serious health risks, and to give people access to innovations like ELF, so that they can live their best lives,” said Renown’s chief scientific officer, Dr. Joseph Grzymski, who is also a research professor at the Desert Research Institute and principal investigator of the Healthy Nevada Project ®. It’s incredibly rewarding to be able to report clinical findings to help our 50,000 volunteer study participants, and to assist healthcare providers in helping their patients.”
The provision of the ELF Test builds on a previously announced strategic collaboration between the Renown IHI and Gilead in July 2019. This ongoing partnership aims to collect and analyze de-identified genetic and electronic health data from 60,000 qualifying study participants to enhance the understanding of NAFLD and NASH and to potentially inform development of treatment options for these diseases.
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About NAFLD and NASH
NAFLD is a build-up of fat in the liver of people who do not have a history of alcohol misuse. It is normal for the liver to contain some fat, but if more than 5 percent of the liver content is fat, it’s considered a fatty liver (steatosis). NASH is the most severe form of NAFLD in which a person has liver cell damage and inflammation of the liver. Inflammation and liver cell damage can cause fibrosis, or scarring of the liver, and can cause decreased liver function (1). The symptoms of NASH are often silent or non-specific, making it difficult to diagnose. About one-third of people with NASH develop cirrhosis or irreversible liver damage (2).
About the ELF™ Test
The ELF Test is a noninvasive blood test that can quickly identify which patients are at an elevated risk for developing cirrhosis and other liver-related clinical events (LREs). In contrast to standard liver enzyme tests that reflect liver damage that has already occurred, the ELF Test combines the three serum direct biomarkers of active fibrosis.
The ELF Test algorithm measures each of these biomarkers to create an ELF score, which can be used as an aid to assess the risk for future disease progression. Doctors may use this ELF score to help evaluate if a patient requires increased medical care and monitoring for their condition. Individuals interested in determining their risk for NASH and its progression are encouraged to enroll in the Nonalcoholic Steatohepatitis Liver Disease Genome Atlas study. Those who have already consented and participated in the study will be contacted with more information on how to receive an ELF blood test. For more information or to enroll, please contact RenownIHI@renown.org or (775) 982-6914.
The Enhanced Liver Fibrosis (ELF™) Test kit is not available for sale in the U.S. Product availability may vary from country to country and is subject to varying regulatory requirements.
In the U.S., the ELF Testing Service is available from Siemens Healthcare Laboratory, LLC (SHL), a CLIA-certified laboratory located in Berkeley, Calif. The ELF Testing Service, including the establishment of performance characteristics, was developed by SHL. The ELF Test has not been cleared or approved by the U.S. Food and Drug Administration. SHL is regulated under CLIA as qualified to perform high complexity testing. The ELF Test is used for clinical purposes and should not be regarded as investigational use only or research use only.
About Renown Health
Renown Health is the region’s largest, locally owned and governed, not-for-profit integrated healthcare network serving Nevada, Lake Tahoe and northeast California. With a diverse workforce of more than 7,000 employees, Renown has fostered a longstanding culture of excellence, determination and innovation. The organization comprises a trauma center, two acute care hospitals, a children’s hospital, a rehabilitation hospital, a medical group and urgent care network, and the region’s largest, locally owned not-for-profit insurance company, Hometown Health. Renown’s institute model addresses social determinants of health and includes: Child Health, Behavioral Health & Addiction, Healthy Aging and Health Innovation. Clinical institutes include: Cancer, Heart and Vascular Health, Neurosciences and Robotic Surgery. Renown is currently enrolling participants in the world’s largest community-based genetic population health study, the Healthy Nevada Project®. For more information visit, renown.org.
About the Renown Institute for Health Innovation
Renown Institute for Health Innovation is a collaboration between Renown Health – a locally governed and locally owned, not-for-profit integrated healthcare network serving Nevada, Lake Tahoe and northeast California; and the Desert Research Institute – a recognized world leader in investigating the effects of natural and human-induced environmental change and advancing technologies aimed at assessing a changing planet. Renown IHI research teams are focused on integrating personal healthcare and environmental data with socioeconomic determinants to help Nevada address some of its most complex environmental health problems; while simultaneously expanding the state’s access to leading-edge clinical trials and fostering new connections with biotechnology and pharmaceutical companies.
Renown Health is Nevada’s most comprehensive and integrated healthcare network and maintains electronic health records for 1.02 million registered patients. In 2016, Renown Health and the Desert Research Institute established the Healthy Nevada Project (HNP), the nation’s first community-based population health study. In 2017 HNP began a partnership with Helix to leverage its population health services, Exome+™ sequencing, and consumer engagement tools. The HNP is now an ongoing collaboration between Renown IHI, the Desert Research Institute, a global leader in environmental data and applied research, and Helix, a personal genomics company. HNP combines genetic, environmental, social and clinical data to address individual and community health needs with the goal of improving health across the state and the nation. The HNP currently has over 60,000 participants. For more information, visit healthynv.org.
About Gilead Sciences
Gilead Sciences, Inc. is a research-based biopharmaceutical company that discovers, develops and commercializes innovative medicines in areas of unmet medical need. The company strives to transform and simplify care for people with life-threatening illnesses around the world. Gilead has operations in more than 35 countries worldwide, with headquarters in Foster City, California. For more information on Gilead Sciences, please visit the company’s website at www.gilead.com.
About Siemens Healthineers
Siemens Healthineers AG (listed in Frankfurt, Germany: SHL) is shaping the future of Healthcare. As a leading medical technology company headquartered in Erlangen, Germany, Siemens Healthineers enables healthcare providers worldwide through its regional companies to increase value by empowering them on their journey towards expanding precision medicine, transforming care delivery, improving the patient experience, and digitalizing healthcare. Siemens Healthineers is continuously developing its product and service portfolio, with AI-supported applications and digital offerings that play an increasingly important role in the next generation of medical technology. These new applications will enhance the company’s foundation in in-vitro diagnostic, image-guided therapy, and in-vivo diagnostics. Siemens Healthineers also provides a range of services and solutions to enhance healthcare providers ability to provide high-quality, efficient care to patients. In fiscal 2020, which ended on September 30, 2020, Siemens Healthineers, which has approximately 54,000 employees worldwide, generated revenue of €14.5 billion and adjusted EBIT of €2.2 billion. Further information is available at www.siemens-healthineers.com.
Dec 14, 2020 | News releases, Research findings
What happens when rain falls on desert soils?
DEC. 14, 2020
LAS VEGAS, NEV.
An updated model from DRI scientists in Las Vegas provides a new understanding of water movement in dry soils
Several years ago, while studying the environmental impacts of large-scale solar farms in the Nevada desert, Desert Research Institute (DRI) scientists Yuan Luo, Ph.D. and Markus Berli, Ph.D. became interested in one particular question: how does the presence of thousands of solar panels impact desert hydrology?
This question led to more questions. “How do solar panels change the way water hits the ground when it rains?” they asked. “Where does the water go? How much of the rain water stays in the soil? How deep does it go into the soil?”
“To understand how solar panels impact desert hydrology, we basically needed a better understanding of how desert soils function hydraulically,” explained Luo, postdoctoral researcher with DRI’s Division of Hydrologic Sciences and lead author of a new study in Vadose Zone Journal.
DRI scientists Yuan Luo (left) and Markus Berli (right) conducting research at DRI’s SEPHAS Lysimeter facility in Boulder City, Nev. November 2020.
Photograph by Ali Swallow/DRI.
In the study, Luo, Berli, and colleagues Teamrat Ghezzehei, Ph.D. of the University of California, Merced, and Zhongbo Yu, Ph.D. of the University of Hohai, China, make important improvements to our understanding of how water moves through and gets stored in dry soils by refining an existing computer model.
The model, called HYDRUS-1D, simulates how water redistributes in a sandy desert soil based on precipitation and evaporation data. A first version of the model was developed by a previous DRI graduate student named Jelle Dijkema, but was not working well under conditions where soil moisture levels near the soil surface were very low.
To refine and expand the usefulness of Dijkema’s model, Luo analyzed data from DRI’s SEPHAS Lysimeter facility, located in Boulder City, Nev. Here, large, underground, soil-filled steel tanks have been installed over truck scales to allow researchers to study natural water gains and losses in a soil column under controlled conditions.
Above: Yuan Luo and Markus Berli of DRI’s Division of Hydrologic Sciences used data from DRI’s SEPHAS Lysimeter facility (shown here) to refine an existing model called HYDRUS-1D, which simulates how water moves through dry soils.
Photographs by Ali Swallow/DRI.
Using data from the lysimeters, Luo explored the use of several hydraulic equations to refine Dijkema’s model. The end result, which is described in the new paper, was an improved understanding and model of how moisture moves through and is stored in the upper layers of dry desert soils.
“The first version of the model had some shortcomings,” Luo explained. “It wasn’t working well for very dry soils with volumetric water content lower than 10 percent. The SEPHAS lysimeters provided us with really good data to help understand the phenomenon of how water moves through dry soils as a result of rainfall and evaporation.”
In desert environments, understanding the movement of water through soils is helpful for a variety of practical uses, including soil restoration, erosion and dust management, and flood risk mitigation. For example, this model will be useful for desert restoration projects, where project managers need to know how much water will be available in the soil for plants after a desert rainstorm, Berli said. It is also a key piece of the puzzle needed to help answer their original question about how solar farms impact desert hydrology.
“The model is very technical, but all of this technical stuff is just a mathematical way to describe how rainwater moves in the soil once the water hits the soil,” Berli said. “In the bigger picture, this study was motivated by the very practical question of what happens to rainwater when falling on solar farms with thousands and thousands of solar panels in the desert – but to answer questions like that, sometimes you have to dig deep and answer more fundamental questions first.”
DRI scientist Yuan Luo standes near a weighing lysimeter at DRI’s SEPHAS Lysimeter facility in Boulder City, Nev. November 2020.
Photograph by Ali Swallow/DRI.
“In the bigger picture, this study was motivated by the very practical question of what happens to rainwater when falling on solar farms with thousands and thousands of solar panels in the desert – but to answer questions like that, sometimes you have to dig deep and answer more fundamental questions first.”
Additional Information:
This study was funded by the DRI Foundation Innovative Research Program, the National Science Foundation, and the U.S. Army Corps of Engineers. Rose Shillito, Ph.D. (DRI/ACOE) and Nicole Damon (DRI) also contributed to the success of this project.
The full text of the paper “Modeling near-surface water redistribution in a desert soil”, is available from Vadose Zone Journal: https://doi.org/10.1002/vzj2.20081
To learn more about DRI’s SEPHAS Lysimeter facility, please visit: https://www.dri.edu/sephas/lysimeters/
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
DRI scientists Markus Berli and Yuan Luo. November 2020.
Photograph by Ali Swallow/DRI.
Nov 19, 2020 | News releases, Research findings
Climate change and “atmospheric thirst” to increase fire danger and drought in Nevada and California
Climate Change
Wildfire
Drought
New study shows impacts of increased levels of evaporative demand as climate grows warmer and drier
Climate change and a “thirsty atmosphere” will bring more extreme wildfire danger and multi-year droughts to Nevada and California by the end of this century, according to new research from the Desert Research Institute (DRI), the Scripps Institution of Oceanography at the University of California, San Diego, and the University of California, Merced.
In a new study published in Earth’s Future, scientists looked at future projections of evaporative demand – a measure of how dry the air is – in California and Nevada through the end of the 21st century. They then examined how changes in evaporative demand would impact the frequency of extreme fire danger and three-year droughts, based on metrics from the Evaporative Demand Drought Index (EDDI) and the Standardized Precipitation Evapotranspiration Index (SPEI).
According to their results, climate change projections show consistent future increases in atmospheric evaporative demand (or the “atmospheric thirst”) over California and Nevada. These changes were largely driven by warmer temperatures, and would likely lead to significant on-the-ground environmental impacts.
Study results show increases of 13 to 18 percent in evaporative demand during all four seasons by the end of the century.
“Higher evaporative demand during summer and autumn—peak fire season in the region—means faster drying of soil moisture and vegetation, and available fuels becoming more flammable, leading to fires that can burn faster and hotter,” explained lead author Dan McEvoy, Ph.D., Assistant Research Professor of Climatology at DRI.
“Increased evaporative demand with warming enables fuels to be drier for longer periods,” added coauthor John Abatzoglou, Ph.D., Associate Professor with the University of California, Merced. “This is a recipe for more active fire seasons.”
The research team found that days with extreme fire danger in summer and autumn are expected to increase four to 10 times by the end of the century. Their results also showed that multi-year droughts, similar to that experienced in California and Nevada during 2012-2016, were projected to increase three to 15 times by the end of the century.
“One major takeaway was that we can expect to see a lot more days in the summer and autumn with extreme fire danger related to increased temperature and evaporative demand,” McEvoy said. “Another takeaway was that even in locations where precipitation may not change that much in future, droughts are going to become more severe due to higher evaporative demand.”
California and Nevada on average experienced a record-setting number of “extreme fire danger” days in 2020, as indicated by the line on the graph above. Extreme fire danger days were calculated using the Evaporative Demand Drought Index (EDDI), with methods described in McEvoy et al. (2020). Data source: http://www.climatologylab.org/gridmet.html.
Study authors say that the cumulative effects of increases in evaporative demand will stress native ecosystems, increase fire danger, negatively impact agriculture where water demands cannot be met, and exacerbate impacts to society during periods of prolonged dryness. Several members of the research team are part of the California-Nevada Applications Program (CNAP), and will use these study results to provide resource managers with a view of possible future scenarios.
“These results provide information to support science-based, long-term planning for fire management agencies, forest management agencies, and water resource managers,” said coauthor Julie Kalansky, Ph.D., Program Manager for CNAP. “We plan to work with partners to help integrate the findings from this paper to support building climate resilience.”
Additional Information:
This study was funded by the National Oceanic and Atmospheric Administration (NOAA) California-Nevada Climate Applications Program (CNAP) and the NOAA National Integrated Drought Information System (NIDIS) California-Nevada Drought Early Warning System.
The full text of the paper, “Projected Changes in Reference Evapotranspiration in California and Nevada: Implications for Drought and Wildland Fire Danger,” is available from Earth’s Future: https://doi.org/10.1029/2020EF001736.
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Sep 22, 2020 | News releases, Research findings
Photo caption: Smoke from wildfires covering the city of Sparks, Nevada. Credit: GChapel, Adobe Images.
Reno, Nev. (Sept. 22, 2020) – For people who suffer from asthma, wildfire smoke is more hazardous than other types of air pollution, according to a new study from the Desert Research Institute (DRI), the Renown Institute for Health Innovation (Renown IHI) and the Washoe County Health District (WCHD).
The study, which published last month in the journal Environmental Health, examined associations between airborne particulate matter (PM) from sources such as wildfire, transportation and industry, and medical visits for asthma at Renown Health’s emergency departments and urgent care centers in Reno, Nev. during the six-year period from 2013-2018.
According to their results, on days when wildfire smoke was present, elevated levels of PM2.5 (fine particles of 0-2.5 micrometers in size, about 30 times smaller than a human hair) led to a 6.1 percent increase in medical visits for asthma patients when compared with days of similar pollution levels that came from non-wildfire sources.
“Since we found significantly stronger associations of PM2.5 with asthma visits when wildfire smoke was present, our results suggest that wildfire PM is more hazardous than non-wildfire PM for patients with asthma,” said lead author Daniel Kiser, M.S., Data Scientist with DRI and Renown IHI.
Above, a timelapse video from DRI’s Western Regional Climate Center shows an impressive smoke front move into the city of Reno on August 18, 2013. The smoke, which rolls in at approximately 1:05 in the video, was from the American River fire near Sacramento, Calif.
An increase in the harmfulness of PM from wildfires compared to PM from other sources may be attributable to differences in the chemical composition of PM or changes in human behavior, since people are more likely to be outdoors in the summer, when wildfires typically occur. The research team notes that caution should be used when applying these results to other areas of the country, such as the Southeastern United States, since the harmfulness of wildfire smoke may be affected by the type of fuel that is being burned. Other factors, such as the distance that wildfire smoke was carried by the wind and burn temperature, may also play a role in the harmfulness of wildfire smoke.
The researchers found that air quality in the Reno area was affected by wildfire smoke on a total of 188 days during the study period. A total of 18,836 asthma-related emergency room and urgent care visits occurred over the same five-year period of time, indicating that the influences of wildfire smoke and other types of air pollution on this medical condition are important to understand.
“In places like Reno, where wildfire events occur regularly during parts of the year and are expected to become more frequent in the future, an accurate understanding of the impacts of wildfire smoke on population health is critical,” Kiser said.
From left to right, this series of three photos documents recent air quality conditions on clear, moderate, very smoky days in Stead, Nev. Credit: Daniel Kiser/DRI.
Additional Information:
The full text of the article “Particulate matter and emergency visits for asthma: a time-series study of their association in the presence and absence of wildfire smoke in Reno, Nevada, 2013–2018,” is available from Environmental Health: https://ehjournal.biomedcentral.com/articles/10.1186/s12940-020-00646-2
To learn more about the Renown Institute for Health Innovation, please visit: https://www.dri.edu/renown-ihi/
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About the Desert Research Institute
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policymakers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, visit www.dri.edu.
Jul 27, 2020 | News releases, Research findings
Healthy Nevada Project’s community-based approach reveals up to 90% of CDC Tier 1 genetic condition risks missed using clinical care guidelines
Reno, Nev. (July 27, 2020) – In a new study published today in the journal Nature Medicine, researchers behind the Healthy Nevada Project® suggest that community-based genetic screening has the potential to efficiently identify individuals who may be at increased risk for three common inherited genetic conditions known to cause several forms of cancer and increased risk for heart disease or stroke.
In 2018, the Healthy Nevada Project® (the largest, community-based population health study combining genetic, clinical, environmental, and social data) started notifying consenting study participants who have certain genetic variants that predispose them to the Centers for Disease Control and Prevention (CDC) Tier 1 genetic conditions. The study focused on identifying carriers of these conditions, which include Hereditary Breast and Ovarian Cancer, Lynch Syndrome, and Familial Hypercholesterolemia, because they are the most common conditions and early detection and treatment could significantly lower morbidity and mortality.
Initial results from almost 27,000 study participants showed that 90% of carriers of the CDC Tier 1 genetic conditions were not previously identified in a clinical setting. The authors conclude that population genetic screening would identify at-risk carriers not identified during routine care.
“Our first goal was to deliver actionable health data back to the participants of the study and understand whether or not broad population screening of CDC Tier 1 genomic conditions was a practical tool to identify at-risk individuals,” explained Joseph Grzymski, Ph.D., the principal investigator of the Healthy Nevada Project®, a research professor at the Desert Research Institute (DRI), chief scientific officer for Renown Health and lead author of the study.
“Now, two years into doing that, it is clear that the clinical guidelines for detecting risk in individuals are too narrow and miss too many at-risk individuals.”
Within the group of 26,906 Healthy Nevada Project® participants that Grzymski’s research team studied, 358 (1.33%) were carriers for CDC Tier 1 conditions. However, only 25% of those individuals met clinical guidelines for genetic screening. Additionally, more than 20% of the carriers already had a diagnosis of disease-relevant to their underlying genetic condition.
“We’re at a point now where it’s possible to do clinical-grade genetic screening at population-scale,” added James Lu, M.D. Ph.D., co-founder and chief scientific officer of Helix and senior co-author of the study. “What this study demonstrates is the potential impact of doing so. By making genetic screening available more broadly, we can help the millions of Americans who are unaware that they are living at increased risk for highly actionable, genetic conditions take action.”
Most notably, the study found that of the 273 participants who were carriers of the CDC Tier 1 genetic conditions and had clinical record information, only 22 individuals showed any previous suspicion of their underlying genetic conditions.
“For the first time, we are providing information at the individual level so study participants can make lifesaving changes to reduce their risk based on their genetics,” said Anthony Slonim, M.D., Dr.PH., FACHE, president and CEO of Renown Health and co-director of the Project® study. “We’re conducting research on the community level to develop leading-edge research on health determinants for entire neighborhoods, states and eventually, the country. Returning these results allows us to understand the prevalence of genetically programmed diseases and illnesses that we have here in Nevada and ensure we are providing the best prevention and care plans. For the individual, the return of results can be lifechanging.”
According to the CDC, early detection and intervention of Tier 1 genetic conditions could have a meaningful potential for clinical actionability and a positive impact on public health.
The Healthy Nevada Project®, which launched in 2016, offers free genetic testing to every Nevadan, aged 18 and older, interested in learning more about their health and genetic profile. With more than 50,000 study participants enrolled in four years, the Healthy Nevada Project® has become the fastest-enrolling genetic study in the world. For more about the Healthy Nevada Project® please visit healthynv.org
Renown Institute for Health Innovation is a collaboration between Renown Health – a locally governed and locally owned, not-for-profit integrated healthcare network serving Nevada, Lake Tahoe and northeast California; and the Desert Research Institute – a recognized world leader in investigating the effects of natural and humaninduced environmental change and advancing technologies aimed at assessing a changing planet. Renown IHI research teams are focused on integrating personal healthcare and environmental data with socioeconomic determinants to help Nevada address some of its most complex environmental health problems; while simultaneously expanding the state’s access to leading-edge clinical trials and fostering new connections with biotechnology and pharmaceutical companies. Learn more at s.
Helix is the leading population genomics company operating at the intersection of clinical care, research, and genomics. Its end-to-end platform enables health systems, life sciences companies, and payers to advance genomic research and accelerate the integration of genomic data into clinical care. Powered by one of the world’s largest CLIA / CAP next-generation sequencing labs and its proprietary Exome+Ⓡ assay, Helix supports all aspects of population genomics including recruitment and engagement, clinically actionable disease screening, return of results, and basic and translational research. In response to the COVID-19 public health crisis, Helix has launched a sensitive and scalable end-to-end COVID-19 test system to meet the needs of health systems, employers, governments, and other organizations across the country. Learn more at www.helix.com.
Media Contacts:
Justin Broglio, APR
Communications Manager, Desert Research Institute
(775) 762-8320
jbroglio@dri.edu
Sarah Bobulsky
Helix
(415) 916-2740
sarah.bobulsky@helix.com
Cassie Harris
Public Relations Business Partner, Renown Health
(775) 691-7308
news@renown.org
Jun 25, 2020 | News releases, Research findings
New study reveals key information about the microbiome of an important anticancer compound-producing Antarctic marine invertebrate
Microbiology
Melanoma
Ascidians
Could the cure for melanoma – the most dangerous type of skin cancer – be a compound derived from a marine invertebrate that lives at the bottom of the ocean? A group of scientists led by Alison Murray, Ph.D. of the Desert Research Institute (DRI) in Reno think so, and are looking to the microbiome of an Antarctic ascidian called Synoicum adareanum to better understand the possibilities for development of a melanoma-specific drug.
Ascidians, or “sea squirts”, are primitive, sac-like marine animals that live attached to ocean-bottoms around the world, and feed on plankton by filtering seawater. S. adareanum, which grows in small colonies in the waters surrounding Antarctica, is known to contain a bioactive compound called “Palmerolide A” with promising anti-melanoma properties – and researchers believe that the compound is produced by bacteria that are naturally associated with S. adareanum.
In a new paper published this month in the journal Marine Drugs, Murray and collaborators from the University of South Florida, the Los Alamos National Laboratory, and the Université de Nantes, France, present important new findings measuring palmerolide levels across samples collected from Antarctica’s Anvers Island Archipelago and characterizing the community of bacteria that make up the microbiome of S. adareanum.
“Our longer-term goal is to figure out which of the many bacteria within this species is producing palmerolide, but to do this, there is a lot we need to learn about the microbiome of S. adareanum,” Murray said. “Our new study describes many advances that we have made toward that goal over the last few years.”
Synoicum adareanum: The Antarctic sea squirt, Synoicum adareanum at 80’ (24 meters) lives amongst the red algae, bryozoans and starfish on the seafloor. It is a non-motile benthic species that gets its nutrition from microorganisms and organic carbon in the seawater. Its microbiome hosts a suite of different microorganisms that can provide defenses against predation and infection in some cases. Tissues of this animal were found to contain high levels of a compound that is active against melanoma, which is thought to be produced by a member of the sea squirt’s microbiome.
In 2008, Murray worked with Bill Baker, Ph.D., of the University of South Florida, and DRI postdoctoral researcher Christian Riesenfeld, Ph.D., to publish a study on the microbial diversity of one individual S. adareanum. Their new study builds upon this research by characterizing the microbial diversity of 63 different individuals that were collected from around Anvers Island.
Their results identify a what the researchers call the “core microbiome” of the species – a common suite of 21 bacterial taxa that were present in more than 80 percent of samples, and six bacterial taxa that were present in all 63 samples.
“It is a key “first” for Antarctic science to have been able to find and identify this core microbiome in a fairly large regional study of these organisms,” Murray said. “This is information that we need to get to the next step of identifying the producer of palmerolide.”
Another “first” for Antarctic science, and for the study of natural products in nature in general, was a comparison of palmerolide levels across all 63 samples that showed the compound was present in every specimen at high (milligram per gram specimen tissue) levels, but the researchers found no trends between sites, samples, or microbiome bacteria. Additional analysis looking at the co-occurrence relationships of the taxa across the large data set showed some of the ways that bacteria are interacting with each other and with the host species in this marine ecosystem.
“The microbiome itself is unique in composition from other ascidians, and seems to be pretty interesting, with a lot of interaction,” Murray said. “Our study has opened the doors to understand the ecology of this system.”
From the assemblage of bacteria that the researchers have identified as making up the core microbiome of S. adareanum, they next hope to use a genomics approach to finally be able to identify which of the bacteria are producing palmerolide – an important and needed advancement toward the development of a melanoma treatment.
“It would be a really big deal to use this compound to develop a drug for fighting melanoma, because there are just so few drugs at the moment that can be used to treat it,” Murray said. “If we can identify the bacteria that produce this chemical, and with its genome understand how to cultivate it in a laboratory setting, this would enable us to provide a sustainable supply of palmerolide that would not rely on harvesting wild populations of this species in Antarctica.”
Anvers Island Antarctica: Samples for microbiome characterization were collected by SCUBA divers working on the sea ice off Anvers Island, in the Antarctic Peninsula. Diving through holes cut in the sea ice requires dry suites, and relatively short dive times. (photographed Prof. Bill Baker in the hole, and his graduate student Chris Petri suited on the sled).
DNA-stained micrograph: Cultivation efforts led to isolation of a new bacterial species affiliated with the Pseudovibrio genus – a group known to produce bioactive compounds – this is the first cold-adapted member of this genus. This strain has unusual branching morphology (seen in the DNA-stained micrograph), and storage granules that appear yellow.
“It is a key “first” for Antarctic science to have been able to find and identify this core microbiome in a fairly large regional study of these organisms,” Murray said. “This is information that we need to get to the next step of identifying the producer of palmerolide.”
Additional information
The full text of the study, “Uncovering the Core Microbiome and Distribution of Palmerolide in Synoicum adareanum Across the Anvers Island Archipelago, Antarctica,” is available from Marine Drugs: https://www.mdpi.com/1660-3397/18/6/298/htm
This research was supported by the National Institute of Health, National Cancer Institute, and the National Science Foundation.
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About the Desert Research Institute
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Media Contact
Justin Broglio
Communications Manager, Desert Research Institute
775-762-8320
Justin.Broglio@dri.edu
@DRIScience
Jun 22, 2020 | News releases, Research findings
Reno, Nev. (June 22, 2020) – An international team of scientists and historians has found evidence connecting an unexplained period of extreme cold in ancient Rome with an unlikely source: a massive eruption of Alaska’s Okmok volcano, located on the opposite side of the Earth.
Around the time of Julius Caesar’s death in 44 BCE, written sources describe a period of unusually cold climate, crop failures, famine, disease, and unrest in the Mediterranean Region – impacts that ultimately contributed to the downfall of the Roman Republic and Ptolemaic Kingdom of Egypt. Historians have long suspected a volcano to be the cause, but have been unable to pinpoint where or when such an eruption had occurred, or how severe it was.
In a new study published this week in Proceedings of the National Academy of Sciences (PNAS), a research team led by Joe McConnell, Ph.D. of the Desert Research Institute in Reno, Nev. uses an analysis of tephra (volcanic ash) found in Arctic ice cores to link the period of unexplained extreme climate in the Mediterranean with the caldera-forming eruption of Alaska’s Okmok volcano in 43 BCE.
“To find evidence that a volcano on the other side of the earth erupted and effectively contributed to the demise of the Romans and the Egyptians and the rise of the Roman Empire is fascinating,” McConnell said. “It certainly shows how interconnected the world was even 2,000 years ago.”
Alaska’s Umnak Island in the Aleutians showing the huge, 10-km wide caldera (upper right) largely created by the 43 BCE Okmok II eruption at the dawn of the Roman Empire. Landsat-8 Operational Land Imager image from May 3, 2014. Credit: U.S. Geological Survey.
The discovery was initially made last year in DRI’s Ice Core Laboratory, when McConnell and Swiss researcher Michael Sigl, Ph.D. from the Oeschger Centre for Climate Change Research at the University of Bern happened upon an unusually well-preserved layer of tephra in an ice core sample and decided to investigate.
New measurements were made on ice cores from Greenland and Russia, some of which were drilled in the 1990s and archived in the U.S., Denmark, and Germany. Using these and earlier measurements, they were able to clearly delineate two distinct eruptions – a powerful but short-lived, relatively localized event in early 45 BCE, and a much larger and more widespread event in early 43 BCE with volcanic fallout that lasted more than two years in all the ice core records.
The researchers then conducted a geochemical analysis of the tephra samples from the second eruption found in the ice, matching the tiny shards with those of the Okmok II eruption in Alaska – one of the largest eruptions of the past 2,500 years.
“The tephra match doesn’t get any better,” said tephra specialist Gill Plunkett, Ph.D. from Queen’s University Belfast. “We compared the chemical fingerprint of the tephra found in the ice with tephra from volcanoes thought to have erupted about that time and it was very clear that the source of the 43 BCE fallout in the ice was the Okmok II eruption.”
Detailed records of past explosive volcanic eruptions are archived in the Greenland ice sheet and accessed through deep-drilling operations. Credit: Dorthe Dahl-Jensen.
Working with colleagues from the U.K., Switzerland, Ireland, Germany, Denmark, Alaska, and Yale University in Connecticut, the team of historians and scientists gathered supporting evidence from around the globe, including tree-ring-based climate records from Scandinavia, Austria and California’s White Mountains, and climate records from a speleothem (cave formations) from Shihua Cave in northeast China. They then used Earth system modeling to develop a more complete understanding of the timing and magnitude of volcanism during this period and its effects on climate and history.
According to their findings, the two years following the Okmok II eruption were some of the coldest in the Northern Hemisphere in the past 2,500 years, and the decade that followed was the fourth coldest. Climate models suggest that seasonally averaged temperatures may have been as much as 7oC (13oF) below normal during the summer and autumn that followed the 43 BCE eruption of Okmok, with summer precipitation of 50 to 120 percent above normal throughout Southern Europe, and autumn precipitation reaching as high as 400 percent of normal.
“In the Mediterranean region, these wet and extremely cold conditions during the agriculturally important spring through autumn seasons probably reduced crop yields and compounded supply problems during the ongoing political upheavals of the period,” said classical archaeologist Andrew Wilson, D.Phil. of the University of Oxford. “These findings lend credibility to reports of cold, famine, food shortage and disease described by ancient sources.”
“Particularly striking was the severity of the Nile flood failure at the time of the Okmok eruption, and the famine and disease that was reported in Egyptian sources,” added Yale University historian Joe Manning, Ph.D. “The climate effects were a severe shock to an already stressed society at a pivotal moment in history.”
Timeline showing European summer temperatures and volcanic sulphur and ash levels in relation to the Okmok II Eruption and significant historic events of the Roman Republic and Ptolemaic Kingdom from 59 to 20 BCE.
Volcanic activity also helps to explain certain unusual atmospheric phenomena that were described by ancient Mediterranean sources around the time of Caesar’s assassination and interpreted as signs or omens – things like solar halos, the sun darkening in the sky, or three suns appearing in the sky (a phenomenon now known as a parahelia, or ‘sun dog’). However, many of these observations took place prior to the eruption of Okmok II in 43 BCE, and are likely related to a smaller eruption of Mt. Etna in 44 BCE.
Although the study authors acknowledge that many different factors contributed to the fall of the Roman Republic and Ptolemaic Kingdom, they believe that the climate effects of the Okmok II eruption played an undeniably large role – and that their discovery helps to fill a knowledge gap about this period of history that has long puzzled archaeologists and ancient historians.
“People have been speculating about this for many years, so it’s exciting to be able to provide some answers,” McConnell said.
Additional information
This project received support from the National Science Foundation, the Sir Nicholas Shackleton Visiting Fellowship, Clare Hall, Cambridge and the John Fell Oxford University Press Research Fund. Additional authors from DRI included Nathan Chellman, Ph.D.
To view the full text of the article “Extreme climate after massive eruption of Alaska’s Okmok volcano in 43 BCE and effects on the late Roman Republic and Ptolemaic Kingdom” in PNAS, please visit: [add link]
For more information on lead author Joe McConnell, Ph.D., and his research, please visit: https://www.dri.edu/directory/joe-mcconnell/
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About the Desert Research Institute
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policymakers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, visit www.dri.edu.
Jun 8, 2020 | News releases, Research findings
International Consortium of Scientists Propose New Naming System for Uncultivated Bacteria and Archaea
Microbiology
Nomenclature
Taxonomy
The long-standing rules for assigning scientific names to bacteria and archaea are overdue for an update, according to a new consensus statement backed by 119 microbiologists from around the globe.
Bacteria and archaea (single-celled organisms that lack cell nuclei) make up two of the three domains of life on Earth, and are named according to the International Code of Nomenclature of Prokaryotes (ICNP; the Code). At present, the Code only recognizes species that can be grown from cultures in laboratories – a requirement that has long been problematic for microbiologists who study bacteria and archaea in the wild.
Since the 1980s, microbiologists have used genetic sequencing techniques to sample and study DNA of microorganisms directly from the environment, across diverse habitats ranging from Earth’s icy oceans to deep underground mines to the surface of human skin. For a vast majority of these species, no method yet exists for cultivating them in a laboratory, and thus, according to the Code, they cannot be officially named.
“There has been a surge in recent years in genome-based discoveries for archaea and bacteria collected from the environment, but no system in place to formally name them, which is creating a lot of chaos and confusion in the field,” said Alison Murray, Ph.D., Research Professor of Biology at the Desert Research Institute (DRI) in Reno. “Being able to represent the diversity of uncultivated organisms known by their genome sequences in a common language is incredibly important.”
Deep-sea hydrothermal vent chimney from the Mid-Atlantic Ridge. Many new microbial genomes have been described from these environments.
Credit: Anna-Louise Reysenbach and Woods Hole Oceanographic Institution.
In an article published this week in the journal Nature Microbiology, Murray and her collaborators present the rationale for updating the existing regulations for naming new species of bacteria and archaea, and propose two possible paths forward.
As a first option, the group proposes formally revising the Code to include uncultivated bacteria and archaea represented by DNA sequence information, in place of the live culture samples that are currently required. As an alternative, they propose creating an entirely separate naming system for uncultivated organisms that could be merged with the Code at some point in the future.
“For researchers in this field, the benefits of moving forward with either of these options will be huge,” said Brian Hedlund, Ph.D., Professor of Life Sciences at the University of Nevada, Las Vegas. “We will be able to create a unified list of all of the uncultivated species that have been discovered over the last few decades and implement universal quality standards for how and when a new species should be named.”
For example, researchers who use DNA sequencing to study the human microbiome – the thousands of species of Bacteria and Archaea that that live inside and on the human body – would have a means of assigning formal names to the species they identify that are not yet represented in culture collections. This would improve the ability for researchers around the world to conduct collaborative studies on topics such as connections between diet and gut bacteria in different human populations, or to build off of previous research.
This micrograph is a representative Antarctic marine sample of bacteria and archaea that has been stained with a fluorescent dye (DAPI) that binds to DNA. A typical sample of Antarctic seawater harbors 200 to over 600 different taxa based on the diversity of 16S rRNA gene sequences. Only a small fraction of this diversity, < 1%, has been cultivated, or matches sequences of cultivated bacteria and archaea in publicly accessible databases. Through developing a nomenclature system that represents the uncultivated majority, a path for communicating diversity will benefit particularly, those microbial scientists working in natural, bio-engineered, and host-associated ecosystems.
Credit: Alison Murray/DRI.
A proposed update to the International Code of Nomenclature of Prokaryotes would allow scientists to assign official names to uncultivated species of Bacteria and Archaea, such as the specimens shown in this enrichment culture of heat-loving Bacteria and Archaea from a hot spring.
Credit: Anna-Louise Reysenbach.
“It sets the framework for a path forward to provide a structured way to communicate the vast untapped biodiversity of the microbial world within the scientific community and across the public domain” said Anna-Louise Reysenbach, Ph.D., Professor of Biology at Portland State University. “That’s why this change is so important.”
The article and proposed plans are the culmination of a series of workshops that were funded by the National Science Foundation. The next step, says Murray, is to figure out an implementation strategy for moving forward with one of the two proposed plans, while engaging the many microbiologists who contributed to this consensus statement and others around the world who want to help see this change enacted. So far, many have been eager to participate.
“This is an exciting field to be in right now because we’re describing diversity of life on Earth and uncovering new phyla just like scientists were back in the 1800s when they were still discovering larger organisms,” Murray said. “Lots of paradigms have been changing in how we understand the way the world works, and how much diversity is out there – and this is another change that needs to be made. We’re going to need to change it or we’re going to live in chaos.”
“Lots of paradigms have been changing in how we understand the way the world works, and how much diversity is out there – and this is another change that needs to be made. We’re going to need to change it or we’re going to live in chaos.”
Additional information
This project was supported by the National Science Foundation. Additional authors included DRI’s Duane Moser, Ph.D.
To view the full text of the aricle “Roadmap for naming uncultivated Archaea and Bacteria” in Nature Microbiology, please visit: https://www.nature.com/articles/s41564-020-0733-x
For more information on lead author Alison Murray, Ph.D. and her research, please visit: https://www.dri.edu/alison-murray-research/
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About the Desert Research Institute
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Media Contact
Kelsey Fitzgerald
Science Writer, Desert Research Institute
775-741-0496
Kelsey.Fitzgerald@dri.edu
@DRIScience
Apr 28, 2020 | News releases, Research findings
A team of leading fire scientists, including DRI’s Adam Watts, PhD, are advocating for fire research to place a priority on the area of prescribed fire science. In a recently published article in Frontiers in Fire Ecology, Watts and colleagues argue that while the vast majority of fire research focuses on issues related to suppressing wildfires, more attention must be paid to prescribed fires, which behave differently and burn more land each year than wildfire. With a greater focus on “fire we use,” authors argue, fire scientists will be able to maximize the societal and ecological benefits of prescribed burning.
The press release below is reposted with permission from Tall Timbers Research Station in Tallahassee, Florida.
Fire researchers provide new agenda for a future with safer fire
April 17, 2020 − Leading fire researchers join together and advocate for new direction and funding to place a priority on prescribed fire science to address the global challenge of managing wildland fires. Prescribed fires are planned burns that protect communities by clearing out overgrowth that fuels out-of-control wildfires and restores and maintains plant and animal biodiversity. The March 2020 peer reviewed article is published in the journal “Fire Ecology” and has been added to the special “Frontiers in Fire Ecology” compilation of manuscripts that represents current advances and directions.
“You can’t just use wildfire research to address prescribed fire needs, the contexts are fundamentally different,” explains lead author Kevin Hiers from Tall Timbers Research Station. Prescribed fires are increasingly recognized as the solution to minimize impacts from wildfires and maintain ecosystem resilience, but there has been a lack of targeted science to support their expanded use. Most of the research has focused on needs and tools for wildfire suppression, despite the fact that prescribed fires cover more area each year, and there is a demonstrated need for science to guide its application and safely increase its use.
Grants from the US Joint Fire Science Program are awarded 3:1 in favor of wildfire- to prescribed-fire-focused research, while we use 4 to 4.5 million hectares of prescribed fire in the US, versus only 2 to 4 million hectares of wildfire occurring each year. Prescribed fire is one of the most effective techniques for enabling a future in which people can live sustainably with fire. The article explains, “A focus on the ‘fires we use’ has an immediate impact on the ability to safely and effectively achieve natural resource objectives for societal benefit and ecosystem resilience.”
Watts pilots the UAS, stationed on the ground near the burn area, during the Prescribed Fire Science Consortium’s 2018 research burn, hosted by the Tall Timbers Research Station and the U.S. Forest Service. Credit: David Goodwin/Southern Fire Exchange.
The researchers, from more than ten organizations spanning the US, also highlight the important role of the individuals who actually apply prescribed fire. Prescribed fire managers bear the responsibility of choosing to start a fire, a decision with weighty career and legal consequences. Given the societal and ecological benefits of their actions, we should be arming them with the best available science and technology. As a complicating factor, climate change is challenging decades of firsthand knowledge prescribed fire managers have used to safely apply beneficial burns. The article identifies the research gaps that provide a blueprint to help fire managers worldwide protect our communities and forests.
Technology is likely to play a big role in the future of prescribed fire. Just as flight simulators are required for airplane pilots, use of such tools for prescribed fire manager training could become a standard supplemental experience to better align fire behavior with prescribed fire planning, implementation, and outcomes.
Tall Timbers is a research station and land conservancy in Tallahassee, Florida, with a primary research focus on the ecology and management of fire-dependent ecosystems. Author information and affiliations for the paper follow. “Prescribed fire science: the case for a refined research agenda” appears in “Fire Ecology” volume 16, Article number: 11 (2020), it is open access and available at the following link https://fireecology.springeropen.com/articles/10.1186/s42408-020-0070-8.
- Tall Timbers Research Station, Tallahassee, Florida, 32312, USA.
Kevin Hiers, J. Morgan Varner, Kevin Robertson & Eric M. Rowell
- USDA Forest Service Center for Forest Disturbance Science, Athens, Georgia, 30602, USA
Joseph J. O’Brien, Scott L. Goodrick & E. Louise Loudermilk
- USDA Forest Service Rocky Mountain Research Station, Missoula, Montana, 59808, USA
Bret W. Butler & Sharon M. Hood
- USDA Forest Service Northern Research Station, Delaware, Ohio, 43015, USA
Matthew Dickinson
- USDA Forest Service Northeastern Area State and Private Forestry, Munson, Florida, 32570, USA
James Furman
- USDA Forest Service Northern Research Station, New Lisbon, New Jersey, 08064, USA
Michael Gallagher
- Southern Fire Exchange, University of Florida & Tall Timbers Research Station, Tallahassee, Florida, 32312, USA
David Godwin
- USDA Forest Service Rocky Mountain Research Station, Moscow, Idaho, 83844, USA
Andrew Hudak
- University of Idaho, Department of Natural Resources & Society, Moscow, Idaho, 83844, USA
Leda N. Kobziar
- Los Alamos National Lab, Los Alamos, New Mexico, 87545, USA
Rodman Linn
- USDA Forest Service Rocky Mountain Research Station, Fort Collins, Colorado, 80526, USA
Sarah McCaffrey
- USDA Forest Service Northern Research Station, Morgantown, West Virginia, 26505, USA
Nicholas Skowronski
- Desert Research Institute, Reno, Nevada, 89512, USA
Adam C. Watts
- USDA Forest Service Forest Products Lab, Madison, Wisconsin, 53726, USA
Kara M. Yedinak
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Media Contact:
Contact: Brian Wiebler
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Sep 16, 2019 | News releases, Research findings
RENO, Nev. (Sept. 16, 2019) – The same chemicals responsible for the pungent smell of a cannabis plant may also contribute to air pollution on a much larger scale, according to new research from the Desert Research Institute (DRI) and the Washoe County Health District (WCHD) in Reno, Nev.
In a new pilot study, DRI scientists visited four cannabis growing facilities in Nevada and California to learn about the chemicals that are emitted during the cultivation and processing of cannabis plants, and to evaluate the potential for larger-scale impacts to urban air quality.
At each facility, the team found high levels of strongly-scented airborne chemicals called biogenic volatile organic compounds (BVOCs), which are naturally produced by the cannabis plants during growth and reproduction. At facilities where cannabis oil extraction took place, researchers also found very high levels of butane, a volatile organic compound (VOC) that is used during the oil extraction process.
“The concentrations of BVOCs and butane that we measured inside of these facilities were high enough to be concerning,” explained lead author Vera Samburova, Ph.D., Associate Research Professor of atmospheric science at DRI. “In addition to being potentially hazardous to the workers inside the cannabis growing and processing facilities, these chemicals can contribute to the formation of ground-level ozone if they are released into the outside air.”
Although ozone in the upper atmosphere provides protection from UV rays, ozone at ground-level is a toxic substance that is harmful for humans to breathe. Ozone can be formed when volatile organic compounds (including those from plants, automobile, and industrial sources) combine with nitrogen oxide emissions (often from vehicles or fuel combustion) in the presence of sunlight. All of these ozone ingredients are in ample supply in Nevada’s urban areas, Samburova explained – and that impacts our air quality.
“Here in our region, unfortunately, we already exceed the national air quality standard for ground-level ozone quite a few times per year,” Samburova said. “That’s why it is so important to answer the question of whether emissions from cannabis facilities are having an added impact.”
A scientist from the Desert Research Institute measures air quality inside of a cannabis growing facility. Credit: Vera Samburova/DRI. 2019.
At one of the four cannabis growing facilities visited during this study, the team measured emission rates over time, to learn about the ozone-forming potential of each individual plant. The results show that the BVOCs emitted by each cannabis plant could trigger the formation of ground-level (bad) ozone at a rate of approximately 2.6g per plant per day. The significance of this number is yet to be determined, says Samurova, but she and her team feel strongly that their findings have raised questions that warrant further study.
“This really hasn’t been studied before,” Samburova said. “We would like to collect more data on emissions rates of plants at additional facilities. We would like to take more detailed measurements of air quality emissions outside of the facilities, and be able to calculate the actual rate of ozone formation. We are also interested in learning about the health impacts of these emissions on the people who work there.”
The cannabis facility personnel that the DRI research team interacted with during the course of the study were all extremely welcoming, helpful, and interested in doing things right, Samburova noted. Next, she and her team hope to find funding to do a larger study, so that they can provide recommendations to the growing facilities and WCHD on optimum strategies for air pollution control.
“With so much growth in this industry across Nevada and other parts of the United States, it’s becoming really important to understand the impacts to air quality,” said Mike Wolf, Permitting and Enforcement Branch Chief for the WCHD Air Quality Management Division. “When new threats emerge, our mission remains the same: Implement clean air solutions that protect the quality of life for the citizens of Reno, Sparks, and Washoe County. We will continue to work with community partners, like DRI, to accomplish the mission.”
This research was funded by the WCHD and DRI. Members of the DRI team included Vera Samburova, Ph.D., Dave Campbell, M.Sc., William R. Stockwell, Ph.D., and Andrey Khlystov, Ph.D. To view this study online, please visit: https://www.tandfonline.com/doi/full/10.1080/10962247.2019.1654038
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
The Washoe County Health District has jurisdiction over all public health matters in Reno, Sparks, and Washoe County through the policy-making Washoe County District Board of Health. The District consists of five divisions: Administrative Health Services, Air Quality Management, Community and Clinical Health Services, Environmental Health Services and Epidemiology & Public Health Preparedness. To learn more, visit https://www.washoecounty.us/health/
Jul 8, 2019 | News releases, Research findings
Photo: Dr. Joe McConnell and graduate student Nathan Chellman work in the ice lab at the Desert Research Institute, in Reno, Nev., on Wednesday, May 15, 2019. Photo by Cathleen Allison/Nevada Momentum.
RENO, Nev. (July 8, 2019) – How did events like the Black Death plague impact the economy of Medieval Europe? Particles of lead trapped deep in Arctic ice can tell us.
Commercial and industrial processes have emitted lead into the atmosphere for thousands of years, from the mining and smelting of silver ores to make currency for ancient Rome to the burning of fossil fuels today. This lead pollution travels on wind currents through the atmosphere, eventually settling on places like the ice sheet in Greenland and other parts of the Arctic.
Because of lead’s connection to precious metals like silver and the fact that natural lead levels in the environment are very low, scientists have found that lead deposits in layers of Arctic ice are a sensitive indicator of overall economic activity throughout history.
In a new study published in the Proceedings of the National Academy of Sciences, researchers from the Desert Research Institute (DRI), the University of Oxford, NILU – Norwegian Institute for Air Research, the University of Copenhagen, the University of Rochester, the Alfred Wegener Institute for Polar and Marine Research used thirteen Arctic ice cores from Greenland and the Russian Arctic to measure, date, and analyze lead emissions captured in the ice from 500 to 2010 CE, a period of time that extended from the Middle Ages through the Modern Period to the present.
This work builds on a study published by some of the same researchers in 2018, which showed how lead pollution in a single ice core from Greenland tracked the ups and downs of the European economy between 1100 BCE and 800 CE, a period which included the Greek and Roman empires.
“We have extended our earlier record through the Middle Ages and Modern Period to the present,” explained Joe McConnell, Ph.D., lead author on the study and Director of DRI’s Ultra-Trace Ice Core Chemistry Laboratory in Reno, Nevada. “Using an array of thirteen ice cores instead of just one, this new study shows that prior to the Industrial Revolution, lead pollution was pervasive and surprisingly similar across a large swath of the Arctic and undoubtedly the result of European emissions. The ice-core array provides with amazing detail a continuous record of European – and later North American – industrial emissions during the past 1500 years.”
“Developing and interpreting such an extensive array of Arctic ice-core records would have been impossible without international collaboration,” McConnell added.
The research team found that increases in lead concentration in the ice cores track closely with periods of expansion in Europe, the advent of new technologies, and economic prosperity. Decreases in lead, on the other hand, paralleled climate disruptions, wars, plagues, and famines.
“Sustained increases in lead pollution during the Early and High Middle Ages (about 800 to 1300 CE), for example, indicate widespread economic growth, particularly in central Europe as new mining areas were discovered in places like the German Harz and Erzgebirge Mountains, “McConnell noted. “Lead pollution in the ice core records declined during the Late Middle Ages and Early Modern Period (about 1300 to 1680 Ce) when plague devastated those regions, however, indicating that economic activity stalled.”
Even with ups and downs over time due to events such as plagues, the study shows that increases in lead pollution in the Arctic during the past 1500 years have been exponential.
“We found an overall 250 to 300-fold increase in Arctic lead pollution from the start of the Middle Ages in 500 CE to 1970s,” explained Nathan Chellman, a doctoral student at DRI and coauthor on the study. “Since the passage of pollution abatement policies, including the 1970 Clean Air Act in the United States, lead pollution in Arctic ice has declined more than 80 percent.”
“Still, lead levels are about 60 times higher today than they were at the beginning of the Middle Ages,” Chellman added.
This study included an array of ice cores and the research team used state-of-the-art atmospheric modeling to determine the relative sensitivity of different ice-core sites in the Arctic to lead emissions.
“Modeling shows that the core from the Russian Arctic is more sensitive to European emissions, particularly from eastern parts of Europe, than cores from Greenland,” explained Andreas Stohl, Ph.D., an atmospheric scientist at NILU and coauthor on the study. “This is why we found consistently higher levels of lead pollution in the Russian Arctic core and more rapid increases during the Early and High Middle Ages as mining operations shifted north and east from the Iberian Peninsula to Great Britain and Germany.”
Lead pollution found in 13 ice cores from three different regions of the Arctic (North Greenland, South Greenland, and the Russian Arctic) from 200 BCE to 2010 CE. Increases in lead deposition coincided with times of economic prosperity, such as the Industrial Revolution in the mid-19th century. Dramatic declines in lead pollution followed crises such as the Black Death Plague Pandemic starting about 1347 CE, as well as pollution abatement policies such as the 1970 U.S. Clean Air Act.
The combination of expertise on this study is unique, continuing collaboration between researchers in fields as different as ice-core chemistry and economic history. These results, the team argues, are a testament to the benefits of interdisciplinary collaboration.
“What we’re finding is interesting not just to environmental scientists who want to understand how human activity has altered the environment,” said Andrew Wilson, Ph.D., Professor of the Archaeology of the Roman Empire at Oxford and co-author on the study. “These ice-core records also are helping historians to understand and quantify the ways that societies and their economies have responded to external forces such as climate disruptions, plagues, or political unrest.”
Collection, analysis, and interpretation of the ice cores used in this study were supported by the U.S. National Science Foundation, NASA, the John Fell Oxford University Press Research Fund and All Souls College, Oxford, the German Ministry of Education and Research, the German Research Foundation, and the Desert Research Institute.
Locations of the 13 Arctic ice-core drilling sites, as well as ancient and medieval lead/silver mines throughout Europe. Atmospheric modeling shows the impact of emissions from different regions on pollution recorded in the Arctic ice cores. The Russian Arctic, for example, is relatively more sensitive to emissions from mines in eastern Europe, while North Greenland is relatively more sensitive to emissions from western Europe.
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policymakers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI is one of eight institutions in the Nevada System of Higher Education. Learn more at www.dri.edu, and connect with us on social media on Facebook, Instagram, and Twitter.
Media Contact:
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This email address is being protected from spambots. You need JavaScript enabled to view it.”>Justin.Broglio@dri.edu
775-673-7610
@DRIscience
Jun 4, 2019 | EEL, News releases, Research findings
Photo: Hotter temperatures and longer, more frequent heat waves are linked to a rising number of deaths in the Las Vegas Valley over the last 10 years.
Las Vegas, Nev. (June 4, 2019) – Over the last several decades, extreme heat events around the world—particularly in the North American Southwest—have gotten hotter, occurred more frequently, and lasted longer. These trends pose significant health risks to the growing number of people making cities like Las Vegas home.
A new study by faculty and undergraduate students at the Desert Research Institute (DRI), Nevada State College, and Universidad de Las Americas Puebla traces the relationship between extreme heat and mortality rates, identifying a clear correlation between heat wave episodes and heat-related deaths in Las Vegas over the last ten years.
“Current climate change projections show an increased likelihood of extreme temperature events in the Las Vegas area over the next several years,” explained Erick Bandala, Ph.D., assistant research professor at DRI and lead author on the study. “Understanding recent extreme heat trends and their relationship to health hazards is essential to protecting vulnerable populations from risk in the future.”
Erick Bandala, PhD (left), shows a graduate student the data he and his team analyzed for this study.
Urban areas of the Southwest are of particular concern because several factors compound the health-related risks of extreme heat events. The heat-absorbing properties of common materials like asphalt exacerbate already high temperatures in cities (called the urban heat island effect), particularly at night. What’s more, populations in cities like Las Vegas are growing rapidly, especially among those 55 and older, which means that more and more people are exposed to risk.
In this study, the research team analyzed two measures of extreme heat—heat index and excess heat factor—for the Las Vegas metropolitan area in the June, July, and August months from 2007 to 2016. Heat index (HI) accounts for how the human body reacts to surface temperature and relative humidity. Excess heat factor measures (EHF) heat wave intensity in relation to historic temperature trends to account for how acclimated the public is to a given temperature threshold. Because both HI and EHF incorporate the human body’s response to extreme heat, they are ideal metrics for assessing public health impacts, and both were shown to rise over the study period.
The annual average of severe heat events per year in Las Vegas also showed significant increases in this study, from an average of 3.3 events per year from 2007-2009 to 4.7 per year in the 2010-2016 period. These findings match historic trends, which show a steady increase in severity and frequency of excess heat in Las Vegas since 1980.
Strikingly, the number of heat-related deaths in Las Vegas map onto these trends: as heat wave intensity increases, the number of heat-related deaths does, too.
Heat Index (HI) and Excess Heat Factor (EHF) are metrics that go beyond just temperature to also account for the human body’s response to heat. This study found that rising trends in these measures tracked closely with the number of heat-related deaths in Las Vegas.
“From 2007 to 2016, there have been 437 heat-related deaths in Las Vegas, with the greatest number of those deaths occurring in 2016,” explained Bandala. “Interestingly, 2016 also shows one of the highest heat index measures over the last 35 years. This shows a clear relationship between increasingly intense heat events in our area and public health effects.”
Bandala’s team found that the subpopulation particularly at risk of heat-related deaths is adults over 50 years old—76% of the heat-related deaths in the study period were individuals in this subpopulation. Of the deaths in this group, almost all individuals also showed evidence of pre-existing heart disease. Researchers note that these findings are highly significant given that the population of adults over 50 in Las Vegas is increasing, with more retirees choosing Clark County as a retirement destination.
Only 23% of heat related deaths occurred in the subpopulation of adults aged 20 to 50 years; interestingly, the most common pre-existing condition for this group was drug and alcohol use. More research is needed to understand how heat is impacting this segment of the population, Bandala noted, because though the number of deaths in this group is comparatively smaller, it is still nearly one quarter of heat-related deaths in the Las Vegas Valley. Additionally, this subpopulation includes economically active adults.
With more intense, more frequent, and longer lasting heat events projected in the coming years, the research team hopes that the trends identified in this study can assist local decision-makers in taking steps to protect the most vulnerable groups in Las Vegas.
“This research helps us better understand the connection between the climate changes we’ve experienced in Las Vegas and their impact to public health over the last 35 years,” Bandala said. “Ideally, this data analysis will help our community adapt to the changes yet to come.”
The full study, titled “Extreme heat and mortality rates in Las Vegas, Nevada: inter-annual variations and thresholds”, is published in the International Journal of Environmental Science and Technology. The study abstract and references are available here: https://link.springer.com/article/10.1007%2Fs13762-019-02357-9
This study is based on work supported in part by the National Science Foundation, NASA, and the Desert Research Institute. Other members of the project team include Kebret Kebede, Nikole Jonsson, Rebecca Murray, and Destiny Green, all of Nevada State College; John Mejia of DRI; and Polioptro Martinez Austria of the Universidad de Las Americas Puebla.
May 9, 2019 | News releases, Research findings
Researchers drill ice cores from a field camp on Mont Blanc in the French Alps. Credit: B. Jourdain, L’Institut des Géosciences de l’Environnement.
RENO, Nev. (May 8, 2019) – Last spring, an international team of researchers led by Joe McConnell, PhD, Director of the Ultra Trace Ice Core Chemistry Laboratory at DRI’s campus in Reno, Nevada, traced significant atmospheric lead pollution from Roman-era mining and smelting of lead-silver ores in an ice core record from Greenland, providing new insights about the Roman economy.
Now working with colleagues at the Institute of Geosciences and the Environment in Grenoble, France, some members of the same research team have published findings that show a related record of pollution in an ice core from the Col du Dôme area of Mont Blanc in the French Alps.
Published in Geophysical Research Letters, the new study reveals significant atmospheric pollution from lead and antimony, another toxic heavy metal. This study is the first to document an ice core record of antimony, showing that Roman-era mining and smelting activities had implications beyond lead contamination.
Lead (black) and antimony (red) concentrations in ice from the Col du Dôme (CDD). On the bottom scale, age is indicated in years. Phases of increasing lead emissions were accompanied by a simultaneous rise in the presence of antimony – another toxic metal – in the alpine ice. The increases and decreases in heavy metal concentration in the ice correspond with boom times and crises in Roman-era economic history.
“This is the first study of antiquity-era pollution using Alpine ice,” explained lead author Susanne Preunkert, PhD, of the CNRS Institute of Geosciences and the Environment. “Our record from the Alps provides insight into the impact of ancient emissions on the present-day environment in Europe, as well as a comparison with more recent pollution linked to the use of leaded gasoline in the twentieth century.”
Compared to the lead pollution record obtained from a Greenland ice core in the previous study, which reflects heavy metal emissions from across Europe, the Mont Blanc ice core reflects influences from more local pollution sources.
“This study continues an international collaboration between ice core experts, historians, and atmospheric scientists,” said McConnell. “Cross-disciplinary research like this allows us to interpret the ice record in more detail, leading to a better understanding of the impacts of past human activities on the natural environment while also providing new, more quantitative information on those human activities.”
This research received support from the CNRS, ADEME, and the European Alpclim and Carbosol projects, as well as the Desert Research Institute.
The full study, titled “Lead and Antimony in Basal Ice From Col du Dome (French Alps) Dated With Radiocarbon: A Record of Pollution During Antiquity,” is available here.
François Maginiot of CNRS contributed to this release.
May 7, 2019 | News releases, Research findings
Researchers use a drill to extract one of the Greenland ice core samples that became the basis for this research. Credit: Joe McConnell/DRI.
RENO, Nev. (May 7, 2019) – This week, new research outlining the steady decline of phytoplankton productivity in the North Atlantic since the Industrial Revolution was published in the journal Nature. The study, titled “Industrial-era decline in subarctic Atlantic productivity,” is underpinned by data provided by Joe McConnell, Ph.D., director of DRI’s Ultra-Trace Chemistry Laboratory in Reno, Nev.
The recently published study uses measurements from twelve Greenland ice cores to trace the amount of methanesulfonic acid (MSA)—a byproduct of the emissions from large phytoplankton blooms—in the atmosphere. Since the mid-19th century, the concentration of MSA in ice core records has declined by about 10 percent, which translates to a 10 percent loss of phytoplankton. This loss coincides with steadily rising ocean surface temperatures over the same time period, which suggests that populations may decline further as temperatures continue to rise.
A full press release about these findings, originally published by MIT News, is available below.
North Atlantic Ocean productivity has dropped 10 percent during Industrial era
Phytoplankton decline coincides with warming temperatures over the last 150 years.
Jennifer Chu | MIT News Office
May 6, 2019
Virtually all marine life depends on the productivity of phytoplankton — microscopic organisms that work tirelessly at the ocean’s surface to absorb the carbon dioxide that gets dissolved into the upper ocean from the atmosphere.
Through photosynthesis, these microbes break down carbon dioxide into oxygen, some of which ultimately gets released back to the atmosphere, and organic carbon, which they store until they themselves are consumed. This plankton-derived carbon fuels the rest of the marine food web, from the tiniest shrimp to giant sea turtles and humpback whales.
Now, scientists at MIT, Woods Hole Oceanographic Institution (WHOI), and elsewhere have found evidence that phytoplankton’s productivity is declining steadily in the North Atlantic, one of the world’s most productive marine basins.
In a paper appearing today in Nature, the researchers report that phytoplankton’s productivity in this important region has gone down around 10 percent since the mid-19th century and the start of the Industrial era. This decline coincides with steadily rising surface temperatures over the same period of time.
Matthew Osman, the paper’s lead author and a graduate student in MIT’s Department of Earth, Atmospheric, and Planetary Sciences and the MIT/WHOI Joint Program in Oceanography, says there are indications that phytoplankton’s productivity may decline further as temperatures continue to rise as a result of human-induced climate change.
“It’s a significant enough decline that we should be concerned,” Osman says. “The amount of productivity in the oceans roughly scales with how much phytoplankton you have. So this translates to 10 percent of the marine food base in this region that’s been lost over the industrial era. If we have a growing population but a decreasing food base, at some point we’re likely going to feel the effects of that decline.”
Drilling through “pancakes” of ice
Osman and his colleagues looked for trends in phytoplankton’s productivity using the molecular compound methanesulfonic acid, or MSA. When phytoplankton expand into large blooms, certain microbes emit dimethylsulfide, or DMS, an aerosol that is lofted into the atmosphere and eventually breaks down as either sulfate aerosol, or MSA, which is then deposited on sea or land surfaces by winds.
“Unlike sulfate, which can have many sources in the atmosphere, it was recognized about 30 years ago that MSA had a very unique aspect to it, which is that it’s only derived from DMS, which in turn is only derived from these phytoplankton blooms,” Osman says. “So any MSA you measure, you can be confident has only one unique source — phytoplankton.”
In the North Atlantic, phytoplankton likely produced MSA that was deposited to the north, including across Greenland. The researchers measured MSA in Greenland ice cores — in this case using 100- to 200-meter-long columns of snow and ice that represent layers of past snowfall events preserved over hundreds of years.
“They’re basically sedimentary layers of ice that have been stacked on top of each other over centuries, like pancakes,” Osman says.
The team analyzed 12 ice cores in all, each collected from a different location on the Greenland ice sheet by various groups from the 1980s to the present. Osman and his advisor Sarah Das, an associate scientist at WHOI and co-author on the paper, collected one of the cores during an expedition in April 2015.
“The conditions can be really harsh,” Osman says. “It’s minus 30 degrees Celsius, windy, and there are often whiteout conditions in a snowstorm, where it’s difficult to differentiate the sky from the ice sheet itself.”
The team was nevertheless able to extract, meter by meter, a 100-meter-long core, using a giant drill that was delivered to the team’s location via a small ski-equipped airplane. They immediately archived each ice core segment in a heavily insulated cold storage box, then flew the boxes on “cold deck flights” — aircraft with ambient conditions of around minus 20 degrees Celsius. Once the planes touched down, freezer trucks transported the ice cores to the scientists’ ice core laboratories.
“The whole process of how one safely transports a 100-meter section of ice from Greenland, kept at minus-20-degree conditions, back to the United States is a massive undertaking,” Osman says.
Cascading effects
The team incorporated the expertise of researchers at various labs around the world in analyzing each of the 12 ice cores for MSA. Across all 12 records, they observed a conspicuous decline in MSA concentrations, beginning in the mid-19th century, around the start of the Industrial era when the widescale production of greenhouse gases began. This decline in MSA is directly related to a decline in phytoplankton productivity in the North Atlantic.
“This is the first time we’ve collectively used these ice core MSA records from all across Greenland, and they show this coherent signal. We see a long-term decline that originates around the same time as when we started perturbing the climate system with industrial-scale greenhouse-gas emissions,” Osman says. “The North Atlantic is such a productive area, and there’s a huge multinational fisheries economy related to this productivity. Any changes at the base of this food chain will have cascading effects that we’ll ultimately feel at our dinner tables.”
The multicentury decline in phytoplankton productivity appears to coincide not only with concurrent long-term warming temperatures; it also shows synchronous variations on decadal time-scales with the large-scale ocean circulation pattern known as the Atlantic Meridional Overturning Circulation, or AMOC. This circulation pattern typically acts to mix layers of the deep ocean with the surface, allowing the exchange of much-needed nutrients on which phytoplankton feed.
In recent years, scientists have found evidence that AMOC is weakening, a process that is still not well-understood but may be due in part to warming temperatures increasing the melting of Greenland’s ice. This ice melt has added an influx of less-dense freshwater to the North Atlantic, which acts to stratify, or separate its layers, much like oil and water, preventing nutrients in the deep from upwelling to the surface. This warming-induced weakening of the ocean circulation could be what is driving phytoplankton’s decline. As the atmosphere warms the upper ocean in general, this could also further the ocean’s stratification, worsening phytoplankton’s productivity.
“It’s a one-two punch,” Osman says. “It’s not good news, but the upshot to this is that we can no longer claim ignorance. We have evidence that this is happening, and that’s the first step you inherently have to take toward fixing the problem, however we do that.”
This research was supported in part by the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), as well as graduate fellowship support from the US Department of Defense Office of Naval Research.
Reprinted with permission of MIT News.
May 2, 2019 | News releases, Research findings
Kelly Gleason, assistant professor of environmental science and management at Portland State University, and crew head out in a recently burned forest to collect snow samples. Credit: Kelly Gleason/Portland State University
RENO, Nev. (May 2, 2019) – Forest fires are causing snow to melt earlier in the season, a trend occurring across the western U.S. that may affect water supplies and trigger even more fires, according to a new study by a team of researchers at Portland State University (PSU), the Desert Research Institute (DRI), and the University of Nevada, Reno.
It’s a cycle that will only be exacerbated as the frequency, duration, and severity of forest fires increase with a warmer and drier climate.
The study, published May 2 in the journal Nature Communications, provides new insight into the magnitude and persistence of forest fire disturbance on critical snow-water resources.
Researchers found that more than 11 percent of all forests in the West are currently experiencing earlier snowmelt and snow disappearance as a result of fires.
The team used state-of-the-art laboratory measurements of snow samples, taken in DRI’s Ultra-Trace Ice Core Analytical Laboratory in Reno, Nevada, as well as radiative transfer and geospatial modeling to evaluate the impacts of forest fires on snow for more than a decade following a fire. They found that not only did snow melt an average five days earlier after a fire than before all across the West, but the accelerated timing of the snowmelt continued for as many as 15 years.
“This fire effect on earlier snowmelt is widespread across the West and is persistent for at least a decade following fire,” said Kelly Gleason, the lead author and an assistant professor of environmental science and management in PSU’s College of Liberal Arts and Sciences.
Gleason, who conducted the research as a postdoctoral fellow at the Desert Research Institute, and her team cite two reasons for the earlier snowmelt.
First, the shade provided by the tree canopy gets removed by a fire, allowing more sunlight to hit the snow. Secondly and more importantly, the soot — also known as black carbon — and the charred wood, bark and debris left behind from a fire darkens the snow and lowers its reflectivity. The result is like the difference between wearing a black t-shirt on a sunny day instead of a white one.
In the last 20 years, there’s been a four-fold increase in the amount of energy absorbed by snowpack because of fires across the West.
Burned forests shed soot and burned debris that darken the snow surface and accelerate snowmelt for years following fire. Image Credit: Nathan Chellman/DRI.
“Snow is typically very reflective, which is why it appears white, but just a small change in the albedo or reflectivity of the snow surface can have a profound impact on the amount of solar energy absorbed by the snowpack,” said co-author Joe McConnell, a research professor of hydrology and head of the Ultra-Trace Ice Core Analytical Laboratory at DRI. “This solar energy is a key factor driving snowmelt.”
For Western states that rely on snowpack and its runoff into local streams and reservoirs for water, early snowmelt can be a major concern.
“The volume of snowpack and the timing of snowmelt are the dominant drivers of how much water there is and when that water is available downstream,” Gleason said. “The timing is important for forests, fish, and how we allocate reservoir operations; in the winter, we tend to control for flooding, whereas in the summer, we try and hold it back.”
Early snowmelt is also likely to fuel larger and more severe fires across the West, Gleason said.
“Snow is already melting earlier because of climate change,” she said. “When it melts earlier, it’s causing larger and longer-lasting fires on the landscape. Those fires then have a feedback into the snow itself, driving an even earlier snowmelt, which then causes more fires. It’s a vicious cycle.”
Gleason will continue to build on this research in her lab at PSU. She’s in the first year of a grant from NASA that’ll look at the forest fire effects on snow albedo, or how much sunlight energy its surface reflects back into the atmosphere.
Funding for the study was provided by the Sulo and Aileen Maki Endowment at the Desert Research Institute. Co-authors also included Monica Arienzo and Nathan Chellman from DRI and Wendy Calvin from the University of Nevada, Reno.
The full paper, “Four-fold increase in solar forcing on snow in western U.S. burned forests since 1999,” is available here.
Cristina Rojas of PSU’s College of Liberal Arts and Sciences contributed to this release.
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI is one of eight institutions in the Nevada System of Higher Education.
As Oregon’s only urban public research university, Portland State offers tremendous opportunity to 27,000 students from all backgrounds. Our mission to “Let Knowledge Serve the City” reflects our dedication to finding creative, sustainable solutions to local and global problems. Our location in the heart of Portland, one of America’s most dynamic cities, gives our students unmatched access to career connections and an internationally acclaimed culture scene. “U.S. News & World Report” ranks us among the nation’s most innovative universities.
Apr 8, 2019 | News releases, Research findings
Xuelian Bai, Ph.D., Assistant Research Professor of Environmental Sciences, works with an algae sample in the Environmental Engineering Laboratory at the Desert Research Institute in Las Vegas. Credit: Sachiko Sueki.
LAS VEGAS, Nev. (April 8, 2019) – A common species of freshwater green algae is capable of removing certain endocrine disrupting chemicals (EDCs) from wastewater, according to new research from the Desert Research Institute (DRI) in Las Vegas.
EDCs are natural hormones and can also be found in many plastics and pharmaceuticals. They are known to be harmful to wildlife, and to humans in large concentrations, resulting in negative health effects such as lowered fertility and increased incidence of certain cancers. They have been found in trace amounts (parts per trillion to parts per billion) in treated wastewater, and also have been detected in water samples collected from Lake Mead.
In a new study published in the journal Environmental Pollution, DRI researchers Xuelian Bai, Ph.D., and Kumud Acharya, Ph.D., explore the potential for use of a species of freshwater green algae called Nannochloris to remove EDCs from treated wastewater.
“This type of algae is very commonly found in any freshwater ecosystem around the world, but its potential for use in wastewater treatment hadn’t been studied extensively,” explained Bai, lead author and Assistant Research Professor of environmental sciences with the Division of Hydrologic Sciences at DRI. “We wanted to explore whether this species might be a good candidate for use in an algal pond or constructed wetland to help remove wastewater contaminants.”
Samples of Nannochloris grow in the Environmental Engineering Laboratory at DRI. This species of green algae was found to be capable of removing certain types of endocrine disrupting chemicals from treated wastewater. Credit: Xuelian Bai/DRI.
During a seven-day laboratory experiment, the researchers grew Nannochloris algal cultures in two types of treated wastewater effluents collected from the Clark County Water Reclamation District in Las Vegas, and measured changes in the concentration of seven common EDCs.
In wastewater samples that had been treated using an ultrafiltration technique, the researchers found that the algae grew rapidly and significantly improved the removal rate of three EDCs (17β-estradiol, 17α-ethinylestradiol and salicylic acid), with approximately 60 percent of each contaminant removed over the course of seven days. In wastewater that had been treated using ozonation, the algae did not grow as well and had no significant impact on EDC concentrations.
One of the EDCs examined in the study, triclosan, disappeared completely from the ultrafiltration water after seven days, and only 38 percent remained in the ozonation water after seven days – but this happened regardless of the presence of algae, and was attributed to breakdown by photolysis (exposure to light).
“Use of algae for removing heavy metals and other inorganic contaminants have been extensively studied in the past, but for removing organic pollutants has just started,” said Acharya, Interim Vice President for Research and Executive Director of Hydrologic Sciences at DRI. “Our research shows both some of the potential and also some of the limitations for using Nannochloris to remove EDCs from wastewater.”
Although these tests took place under laboratory conditions, a previous study by Bai and Acharya that published in November 2018 in the journal Environmental Science and Pollution Research examined the impacts of these same seven EDCs on quagga mussels (Dreissena bugensis) collected from Lake Mead. Their results showed that several of the EDCs (testosterone, bisphenol A, triclosan, and salicylic acid) were accumulating in the body tissues of the mussels.
Researcher examines a sample of quagga mussels collected from Lake Mead. A recent study by Bai and Acharya found that endocrine disrupting chemicals are accumulating in the body tissues of these mussels. Credit: Xuelian Bai.
“Algae sit at the base of the food web, thereby providing food for organisms in higher trophic levels such as quagga mussels and other zooplantkons,” Bai said. “Our study clearly shows that there is potential for these contaminants to biomagnify, or build up at higher levels of the food chain in the aquatic ecosystem.”
Bai is now working on a new study looking for antibiotic resistance in genes collected from the Las Vegas Wash, as well as a study of microplastics in the Las Vegas Wash and Lake Mead. Although Las Vegas’s treated wastewater meets Clean Water Act standards, Bai hopes that her research will draw public attention to the fact that treated wastewater is not 100 percent clean, and will also be helpful to utility managers as they develop new ways to remove untreated contaminants from wastewater prior to release.
“Most wastewater treatment plants are not designed to remove these unregulated contaminants in lower concentrations, but we know they may cause health effects to aquatic species and even humans, in large concentrations,” Bai said. “This is concerning in places where wastewater is recycled for use in agriculture or released back into drinking water sources.”
Bai’s research was funded by the Desert Research Institute Maki Endowment, the U.S. Geological Survey, and the Nevada Water Resources Research Institute. The studies mentioned in this release are available from Environmental Pollution and Environmental Science and Pollution Research journals:
Bai, X. and Kumud Acharya. 2019. Removal of seven endocrine disrupting chemicals (EDCs) from municipal wastewater effluents by a freshwater green alga. Environmental Pollution. 247: 534-540. Available: https://www.sciencedirect.com/science/article/pii/S0269749118347894
Bai, X. and Kumud Acharya. 2018. Uptake of endocrine-disrupting chemicals by quagga mussels (Dreissena bugensis) in an urban-impacted aquatic ecosystem. Environmental Science and Pollution Research. 26: 250-258. Available: https://link.springer.com/article/10.1007/s11356-018-3320-4
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as one of eight institutions in the Nevada System of Higher Education.
Feb 19, 2019 | News releases, Research findings
Reno, Nev. (Feb. 19, 2019): Microbes play a key role in Earth’s nitrogen cycle, helping to transform nitrogen gas from the atmosphere back and forth into organic forms of nitrogen that can be used by plants and animals.
New research from the Desert Research Institute in Reno, Nev. provides new insight into how this process happens, through the examination of a unique species of microbe called Intrasporangium calvum that was found in a contaminated groundwater well at Oak Ridge National Laboratory Field Research Station in Tennessee.
The study, which published in Frontiers in Microbiology in January, examined the response of I. calvum to different concentrations of environmental resources and how those differences impacted the microbe’s nitrogen cycling ability. The study team also investigated the evolution of this microbe, the biochemistry behind the reactions, and how each of those factors interact with the environment.
Although most microbes perform just one step in the nitrogen cycle – converting nitrogen gas (N2) from the atmosphere to ammonia (NH3) in the soil, for example – the research team discovered that I. calvum could perform two types of reactions: respiratory ammonification and denitrification. Respiratory ammonification retains nitrogen in an ecosystem as ammonium in the soil or water, while denitrification sends nitrogen on a path back to the atmosphere as a gas.
“The microbe that we studied is unique because it can essentially ‘breathe’ in nitrogen and then send the nitrogen along one of two pathways, ‘exhaling’ either ammonium or nitrous oxide,” said David Vuono, Ph.D., postdoctoral researcher fellow with DRI’s Division of Earth and Ecosystem Sciences and Applied Innovation Center, and lead author of the new study. “This is kind of like humans breathing in oxygen and then having the ability to exhale either carbon dioxide or methane.”
Sample bottles of I. calvum are sterilized via flame in the Genomics Laboratory at DRi. February 2019. Credit: DRI.
With the ability to perform more than one type of reaction – either sending nitrogen back to the atmosphere or retaining it in the soil or water – Vuono and his team wondered what would trigger the microbe to select one pathway versus the other. Previous studies had concluded that the ratio of carbon (C) to nitrate (NO3–) in the surrounding environment was the determining factor, but Vuono wondered if the story wasn’t actually more complex.
In this study, Vuono and his team looked beyond the C:NO3–ratio to investigate the importance of the overall concentration of each nutrient. They tested the response of I. calvumunder conditions of both high and low resource availability, while keeping the ratio of C:NO3–at a constant level.
According to their findings, it is the resource concentration, rather than the C:NO3–ratio, that determines pathway selection. When grown under low carbon concentrations, the team found that these microbes were more likely to process nitrogen by ammonification; under high carbon concentrations, denitrification prevailed.
“As we learned, the concentration of nutrients available to these microbes is what determines where the nitrogen ends up, whether it takes a pathway back towards the atmosphere or returns to ammonium,” Vuono explained. “That is a really important distinction, because depending on the environment that you’re in, you may want to remove nitrogen or you may want to retain it.”
In a waterway, for example, high levels of nitrogen can cause algae blooms and dead zones; by creating conditions that favor denitrification, it is possible that microbes could be triggered to send nitrogen back to the atmosphere. In an agricultural field, on the other hand, nitrogen deficiencies in the soil can lead to poor plant growth; by creating conditions that would promote respiratory ammonification, microbes could be prompted to retain nitrogen in the soils, eliminating or lessening the need for chemical fertilizers.
This study was funded by the Nevada Governor’s Office of Economic Development (GOED), the Desert Research Institute postdoctoral research fellowship program, Ecosystems and Networks Integrated with Genes and Molecular Assemblies (ENIGMA), and Oak Ridge National Laboratory (US Department of Energy, Office of Science, Office of Biological and Environmental Research).
Other DRI scientists who contributed to this study included Robert Read, John A. Arnone III, Iva Neveux, Evan Loney, David Miceli, and Joseph Grzymski.
The full study, titled Resource Concentration Modulates the Fate of Dissimilated Nitrogen in a Dual-Pathway Actinobacterium, is available online from Frontiers in Microbiology (22 January 2019): https://doi.org/10.3389/fmicb.2019.00003
Jan 22, 2019 | News releases, Research findings
Reno, Nev. (January 22, 2019): For meteorologists, effectively communicating weather forecasts and their related dangers is essential in maintaining the health, safety, and resilience of communities. A new study published by a team of researchers from the University of Nevada, Reno (UNR), the Desert Research Institute (DRI), and the National Weather Service (NWS) Reno suggests that effective communication isn’t only about sharing information on upcoming weather events—it’s about building trust and common ground between forecasters and the public.
A common focus of science communication research is the difficulty of communicating technical information about weather forecasts to the public, including the likelihood that the forecasted events will actually come to pass. However, personal risks and uncertainty about potential impacts also affect how people respond to and act upon information about subjects like weather forecasts.
In a study published in the Bulletin of the American Meteorological Society, researchers sought to investigate the effect of personal uncertainties on people’s responses to weather forecasts by analyzing posts by the NWS Reno on Facebook. Researchers analyzed a total of 470 Facebook posts by the NWS Reno and 6,467 user comments on the posts about high impact weather events from January to May 2017. This range overlapped with the Reno area’s record wet period during from October 2016 to April 2017, a time when the region’s residents were impacted by several high impact weather events.
The team’s analysis showed that the public’s uncertainty about weather forecasts isn’t usually technical—more often, it’s personal.
“The NWS Reno’s Facebook community engages far less with the technical uncertainties of forecasts than with the personal risks implied in those forecasts,” said Kathryn Lambrecht, Ph.D., lead author on the study and Assistant Director of the Composition and Communication in the Disciplines program at UNR. “People in this community frequently use the NWS posts to share their own experiences with weather, express concern, and reach out to family and friends, not to calculate the technical likelihood of a forecast.”
What’s more, this study’s results showed that posts that used “commonplaces”—or expressions of common values or norms among a community—generated the strongest responses, many of which acknowledged a connection or understanding between the NWS Reno and its followers on Facebook.
Most of the population in the Reno area is located in valleys where it only snows occasionally. Feet of snow can fall in the higher elevations of the Sierra Nevada with the Reno area receiving little to no snow accumulation, so the public often asks “Is it really going to snow down here [in the valley]?” The commonplace “down here” was added to what became a widely shared and commented forecast graphic on the NWS Reno Facebook page.
Because high-impact weather events can severely impact life and property, it is imperative that the public trusts the information coming from the National Weather Service or emergency managers. Commonplaces, this study revealed, can be an effective way for forecasters to build trust with the community and encourage behavioral changes—like changing driving routes or stocking up on sandbags—that ultimately promote public safety.
From here, the team is considering applying for more funding in order to scale up their research and see if their results are consistent in other regions beyond the Reno area.
Researchers on this study included a meteorologist, an atmospheric scientist, a STEM education expert, and a pair of rhetoricians, scholars who study how communication forms communities—an unusual combination of disciplines.
“Past research has shown that science communication benefits from bringing together multiple types of expertise,” Hatchett said. “Our group came together organically, and the result was a highly transdisciplinary project. Personally, I think it is one of the most unique and collaborative projects I have been a part of, which made it even more fun.”
This project was supported by the Nevada NASA Space Grant Consortium and the Desert Research Institute.
The full study, titled “Improving Visual Communication of Weather Forecasts with Rhetoric” is available online from the Bulletin of the American Meteorological Society: https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-18-0186.1
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI is one of eight institutions in the Nevada System of Higher Education.
Nevada’s land-grant university founded in 1874, the University of Nevada, Renoranks in the top tier of best national universities by U.S. News and World Report and is steadily growing in enrollment, excellence and reputation. The University serves nearly 22,000 students. Part of the Nevada System of Higher Education, the University is home to the University of Nevada, Reno School of Medicine, University of Nevada Cooperative Extension and Wolf Pack Athletics. Through a commitment to world-improving research, student success and outreach benefiting the communities and businesses of Nevada, the University has impact across the state and around the world. For more information, visit www.unr.edu.
Jan 22, 2019 | News releases, Research findings
Reno, Nev. (Jan. 22, 2018): Many Western communities rely on snow from mountain forests as a source of drinking water – but for scientists and water managers, accurately measuring mountain snowpack has long been problematic. Satellite imagery is useful for calculating snow cover across open meadows, but less effective in forested areas, where the tree canopy often obscures the view of conditions below.
Now, a new technique for measuring snow cover using a laser-based technology called lidar offers a solution, essentially allowing researchers to use lasers to “see through the trees” and accurately measure the snow that lies beneath the forest canopy.
In a new study published in Remote Sensing of the Environment, an interdisciplinary team of researchers from Desert Research Institute (DRI), the University of Nevada, Reno (UNR), the California Institute of Technology’s Jet Propulsion Laboratory, and California State University described the first successful use of lidar to measure snow cover under forested canopy in the Sierra Nevada.
“Lidar data is gathered by laser pulses shot from a plane, some of which are able to pass light through the tree canopy right down to the snow surface and create a highly accurate three-dimensional map of the terrain underneath,” explained lead author Tihomir Kostadinov, Ph.D., of California State University San Marcos, who completed the research while working as a postdoctoral researcher at DRI. “Passive optical satellite imaging techniques, which are essentially photographs taken from space, don’t allow you to see through the trees like this. We are only starting to take full advantage of all the information in lidar.”
Rowan Gaffney (UNR) surveying the amount of snow at Sagehen Creek Field Station during the NASA airborne campaigns in March 2016. Credit: A. Harpold.
In this study, researchers worked with NASA’s Airborne Snow Observatory to collect lidar data at the University of California, Berkeley’s Sagehen Creek Field Station in the Sierra Nevada by aircraft on three dates during spring of 2016 when snow was present. Additional lidar data and ground measurements facilities by the long-term operation of Sagehen Creek field station were critical to the success of the study.
Analysis of the datasets revealed that the lidar was in fact capable of detecting snow presence or absence both under canopy and in open areas, so long as areas with low branches were removed from the analysis. On-the-ground measurements used distributed temperature sensing with fiber optic cables laid out on the forest floor to verify these findings.
Tree canopies interact with the snowpack in complex ways, causing different accumulation and disappearance rates under canopies as compared to open areas. With the ability to use lidar data to measure snow levels beneath trees, snow cover estimates used by scientists and resource managers can be made more accurate. The importance of this advance could be far reaching, said team member Rina Schumer, Ph.D., Assistant Vice President of Academic and Faculty Affairs at DRI.
“In the Sierra Nevada, April 1st snow cover is what is used to estimate water supply for the year,” Schumer said. “Being able to more accurately assess snow cover is important for California and Nevada, but also all mountainous areas where snowpack is essential to year-round water supply.”
Snow cover estimates are also used by hydrologists for streamflow forecasts and reservoir management. Snow cover data is important to ecologists and biologists for understanding animal migration, wildlife habitat, and forest health, and it is useful to the tourism and recreation industry for informing activities related to winter snow sports.
Rose Petersky (UNR) surveying the amount of snow under the forest canopy at Sagehen Creek Field Station during the NASA airborne campaigns in April 2016. The photo clearly shows the reduced snow cover under the canopy that is difficult to measure with satellites. Credit: A. Harpold.
Although lidar data is currently collected via airplane and not easily accessible by all who might like to use it, the study team believes that information gleaned from this study could be used to correct data derived from satellite imagery, which is already widely available from NASA’s MODIS sensor and NASA/USGS’s Landsat satellites.
“This is proof of concept for the method that we think could really expand the extent that we measure snow at high resolution in forests,” said team member Adrian Harpold, Ph.D., Assistant Professor with the Department of Natural Resources at UNR. “I’m now working with a student to extend this approach across multiple sites to improve our understanding of the relationship between snow cover in the open versus under the tree canopy. Then, we hope to use that information to correct and improve satellite remote sensing in forested areas.”
This study was part of a larger NASA EPSCoR project titled Building Capacity in Interdisciplinary Snow Sciences for a Changing World, which aimed to develop new research, technology, and education capacity in Nevada for the interdisciplinary study of snowpack. Objectives included an educational goal of training the next generation of scientists.
“This project brought together people who look at snow from different scientific perspectives, and generated a conversation amongst us,” said Alison Murray, Ph.D., Research Professor at DRI and principal investigator of the NASA EPSCoR project. “In addition to bringing together expertise from three institutions in Nevada (DRI, UNR, and UNLV) in hydrology, remote sensing, geosciences, atmospheric chemistry and snow associated life, we developed strategic alliances with NASA’s airborne snow survey. Where the Nevada researchers might have been studying snow on our own, this interdisciplinary project allowed us to look at snow in an integrated fashion and make some important advances.”
The full study, titled Watershed-scale mapping of fractional snow cover under conifer forest canopy using lidar, is available online from Remote Sensing of the Environment: https://www.sciencedirect.com/science/article/abs/pii/S0034425718305467
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. Learn more at www.dri.edu, and connect with us on social media on Facebook, Instagram and Twitter.
Northern Nevada Science Center
2215 Raggio Parkway
Reno, Nevada 89512
PHONE: 775-673-7300
Southern Nevada Science Center
755 East Flamingo Road
Las Vegas, Nevada 89119
PHONE: 702-862-5400
Jan 3, 2019 | News releases, Research findings
Reno, Nev. (January 3, 2018): To protect communities in arid landscapes from devastating wildfires, preparation is key. New research from the Desert Research Institute (DRI) in Reno may aid in the prevention of large fires by helping meteorologists and fire managers in the Southwestern U.S. to forecast periods of likely wildfire activity.
Each summer, from June through September, a weather pattern called the North American monsoon brings thunderstorms to the Southwestern U.S., with lightning that often sparks wildfires.
The new study, which published in the International Journal of Climatology, examined twenty common weather patterns that occur during the North American monsoon season, and identified relationships between certain weather patterns and times of increased fire activity.
One of the most problematic weather patterns, the team learned, was when dry and windy conditions gave way to lightning storms in May and June – a time when fuels tended to be at their driest and monsoon rains had not yet soaked the region with added moisture. When lightning storms were followed by another hot, dry, windy period, increased fire activity was even more likely.
“A lot of fire meteorologists know from experience that this is how things happen, but our study actually quantified it and showed how the patterns unfold,” said lead author Nick Nauslar, Ph.D., who completed this research while working as a graduate student at DRI under Tim Brown, Ph.D. “No one had ever really looked at large fire occurrence in the Southwest and how it related to atmospheric patterns.”
To identify problematic weather patterns, Nauslar and his team looked at monsoon season weather data collected from April through September over the 18-year period from 1995-2013. They then classified wildfire activity over the same period into days or events that were considered “busy” by fire managers in their study area, and used an analysis technique called Self-Organizing Maps to detect relationships between the two datasets.
In addition to identifying relationships between specific weather patterns and fire activity, their analysis also looked for patterns in wildfire occurrence and fire size throughout the season. Analysis of more than 84,000 wildfires showed that although July was the month that the most wildfires occurred, wildfires that occurred during the month of June (prior to the arrival of much monsoonal moisture) were more likely to develop into large fires. In July and August, when the heaviest monsoonal precipitation typically occurs, the percentage of fires that developed into large fires decreased.
“Our goal with this study was to provide fire weather meteorologists in the region with information to help inform fire forecasts, and I think we were able to identify some important patterns,” said Brown, Director of the Western Regional Climate Center at DRI.
Nauslar, who is now employed as a mesoscale assistant and fire weather forecaster for the National Oceanic and Atmospheric Administration (NOAA) Storm Prediction Center in Norman, Oklahoma, hopes that the findings of this study will help fire managers in the Southwest to proactively identify periods when wildfires are more likely to occur, and to allocate firefighting resources accordingly.
“I think a lot of what we learned confirms forecaster experience about the types of atmospheric patterns that are problematic with regard to wildfire occurrence in the Southwest,” Nauslar said. “I hope that people in operations can really use this information, and help refine it and build upon it.
Other DRI scientists who contributed to this research included Benjamin Hatchett, Ph.D., Michael Kaplan, Ph.D., and John Mejia, Ph.D. The full study, titled “Impact of the North American monsoon on wildfire activity in the southwest United States,” is available online from the International Journal of Climatology: https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.5899
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. Learn more at www.dri.edu, and connect with us on social media on Facebook, Instagram and Twitter.
Northern Nevada Science Center
2215 Raggio Parkway
Reno, Nevada 89512
PHONE: 775-673-7300
Southern Nevada Science Center
755 East Flamingo Road
Las Vegas, Nevada 89119
PHONE: 702-862-5400
Dec 5, 2018 | News releases, Research findings
Reno, Nev. (Dec. 5, 2018): The melting of the Greenland ice sheet has increased rapidly in response to Arctic warming, and is likely to continue to do so into the future, according to new research from an international team of scientists including Joe McConnell, Ph.D., of the Desert Research Institute in Reno. Among other findings, their research shows a 250 to 575 percent increase in melt intensity over the last 20 years.
This study team utilized ice cores to reconstruct past melting rates from the present day back to the 1600s, producing the first continuous, multi-century record of surface melt intensity and runoff from the Greenland ice sheet. Previous studies have utilized satellite observations, which only go back to 1978.
McConnell, who is a research professor of hydrology and head of the Ultra-Trace Ice Core Analytical Laboratory at DRI, first became involved in the study in 2003 when his research group drilled and analyzed the contents of a 150-meter (492-foot) ice core from west-central Greenland. This ice core, known as “D5”, was then used by Sarah Das, Ph.D. from Woods Hole Oceanographic Institution (WHOI) to develop the record of surface melting rates used in this study.
In a subsequent 2016 collaboration with WHOI researchers, McConnell’s group also used DRI’s unique continuous ice-core analytical system to analyze a 115-meter (377-foot) ice core known as “NU”, which was collected in 2015 by the study’s lead author Luke Trusel and colleagues. The detailed DRI measurements of more than 20 elements and chemical species in both the D5 and NU ice cores enabled precise dating of the records that underpin the new findings.
Recovering an ice core from west Greenland. Credit: Sarah Has/Woods Hole Oceanographic Institution
The study, titled “Nonlinear Rise in Greenland Runoff in Response to Post-industrial Arctic Warming”, was published in the journal Nature in on December 5, 2018: https://doi.org/10.1038/s41586-018-0752-4. A detailed press release from Woods Hole Oceanographic Institution is below.
Greenland Ice Sheet Melt ‘Off the Charts’ Compared with Past Four Centuries
Surface melting across Greenland’s mile-thick ice sheet began increasing in the mid-19th century and then ramped up dramatically during the 20th and early 21st centuries, showing no signs of abating, according to new research published Dec. 5, 2018, in the journal Nature. The study provides new evidence of the impacts of climate change on Arctic melting and global sea level rise.
“Melting of the Greenland Ice Sheet has gone into overdrive. As a result, Greenland melt is adding to sea level more than any time during the last three and a half centuries, if not thousands of years,” said Luke Trusel, a glaciologist at Rowan University’s School of Earth & Environment and former post-doctoral scholar at Woods Hole Oceanographic Institution, and lead author of the study. “And increasing melt began around the same time as we started altering the atmosphere in the mid-1800s.”
“From a historical perspective, today’s melt rates are off the charts, and this study provides the evidence to prove this,” said Sarah Das, a glaciologist at Woods Hole Oceanographic Institution (WHOI) and co-author of the study. “We found a fifty percent increase in total ice sheet meltwater runoff versus the start of the industrial era, and a thirty percent increase since the 20th century alone.”
Meltwater lakes on the Greenland ice sheet. Credit: Sarah Das/Woods Hole Oceanographic Institution.
Ice loss from Greenland is one of the key drivers of global sea level rise. Icebergs calving into the ocean from the edge of glaciers represent one component of water re-entering the ocean and raising sea levels. But more than half of the ice-sheet water entering the ocean comes from runoff from melted snow and glacial ice atop the ice sheet. The study suggests that if Greenland ice sheet melting continues at “unprecedented rates”—which the researchers attribute to warmer summers—it could accelerate the already fast pace of sea level rise.
“Rather than increasing steadily as climate warms, Greenland will melt increasingly more and more for every degree of warming. The melting and sea level rise we’ve observed already will be dwarfed by what may be expected in the future as climate continues to warm,” said Trusel.
To determine how intensely Greenland ice has melted in past centuries, the research team used a drill the size of a traffic light pole to extract ice cores from the ice sheet itself and an adjacent coastal ice cap, at sites more than 6,000 feet above sea level. The scientists drilled at these elevations to ensure the cores would contain records of past melt intensity, allowing them to extend their records back into the 17th century.
During warm summer days in Greenland, melting occurs across much of the ice sheet surface. At lower elevations, where melting is the most intense, meltwater runs off the ice sheet and contributes to sea level rise, but no record of the melt remains. At higher elevations, however, the summer meltwater quickly refreezes from contact with the below-freezing snowpack sitting underneath. This prevents it from escaping the ice sheet in the form of runoff. Instead, it forms distinct icy bands that stack up in layers of densely packed ice over time.
The core samples were brought back to ice core labs at the U.S. National Science Foundation Ice Core Facility in Denver, Colo., WHOI in Woods Hole, Mass., Wheaton College in Norton, Mass., and the Desert Research Institute in Reno, Nev. where the scientists measured physical and chemical properties along the cores to determine the thickness and age of the melt layers. Dark bands running horizontally across the cores, like ticks on a ruler, enabled the scientists to visually chronicle the strength of melting at the surface from year to year. Thicker melt layers represented years of higher melting, while thinner sections indicated years with less melting.
Iceberg in Disko Bay, west Greenland. Credit Luke Trusel/Rowan University.
Combining results from multiple ice cores with observations of melting from satellites and sophisticated climate models, the scientists were able to show that the thickness of the annual melt layers they observed clearly tracked not only how much melting was occurring at the coring sites, but also much more broadly across Greenland. This breakthrough allowed the team to reconstruct meltwater runoff at the lower-elevation edges of the ice sheet—the areas that contribute to sea level rise.
Ice core records provide critical historical context because satellite measurements—which scientists rely on today to understand melting rates in response to changing climate—have only been around since the late 1970s, said Matt Osman, a graduate student in the MIT-WHOI Joint Program and co-author of the study.
“We have had a sense that there’s been a great deal of melting in recent decades, but we previously had no basis for comparison with melt rates going further back in time,” he said. “By sampling ice, we were able to extend the satellite data by a factor of 10 and get a clearer picture of just how extremely unusual melting has been in recent decades compared to the past.”
Trusel said the new research provides evidence that the rapid melting observed in recent decades is highly unusual when put into a historical context.
“To be able to answer what might happen to Greenland next, we need to understand how Greenland has already responded to climate change,” he said. “What our ice cores show is that Greenland is now at a state where it’s much more sensitive to further increases in temperature than it was even 50 years ago.”
One noteworthy aspect of the findings, Das said, was how little additional warming it now takes to cause huge spikes in ice sheet melting.
“Even a very small change in temperature caused an exponential increase in melting in recent years,” she said. “So the ice sheet’s response to human-caused warming has been non-linear.” Trusel concluded, “Warming means more today than it did in the past.”
Additional co-authors are: Matthew B. Osman, MIT/WHOI Joint Program in Oceanography; Matthew J. Evans, Wheaton College; Ben E. Smith, University of Washington; Xavier Fettweis, University of Leige; Joseph R. McConnell, Desert Research Institute; and Brice P. Y. Noël and and Michiel R. van den Broeke Utrecht University.
This research was funded by the US National Science Foundation, institutional support from Rowan University and Woods Hole Oceanographic Institution, the US Department of Defense, the Netherlands Organization for Scientific Research, the Netherlands Earth System Science Center, and the Belgian National Fund for Scientific Research.
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Link to paper (on and after Dec. 5, 2018): https://doi.org/10.1038/s41586-018-0752-4
News media contacts:
WHOI Media Office- 508-289-3340, media@whoi.edu
Sarah Das, Ph.D., Woods Hole Oceanographic Institution (508) 289-2464 (office), sdas@whoi.edu https://www2.whoi.edu/staff/sdas/
Stephen Levine, News Officer, University Relations, Rowan University(856) 256-5443 (office), (856) 889-0491 (cell), Levines@Rowan.edu
Luke Trusel, Ph.D., School of Earth & Environment, Rowan University (856) 256 5262 (office), (508) 981-3073 (cell), trusel@rowan.edu, https://cryospherelab.org
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education.
Nov 28, 2018 | News releases, Research findings
Reno, Nev. (Nov. 28, 2018): This week, new research on historical climate changes in the Earth’s polar regions by an international team of scientists was published in the journal Nature. The study, titled “Abrupt Ice Age Shifts in Southern Westerlies and Antarctic Climate Forced from the North,” is underpinned by data provided by Joe McConnell, Ph.D., director of DRI’s Ultra-Trace Chemistry Laboratory in Reno, Nev.
The recently published study explains the interconnection between Arctic and Antarctic climates, tracing how strong currents in the North Atlantic during the Ice Age forced Southern Hemisphere climate on two different timescales: first, by rapidly warming Greenland and triggering immediate atmospheric changes in Antarctica due to shifting wind patterns, and second, by cooling the continent via colder ocean temperatures two centuries later. Researchers liken the atmospheric climate change in the North Atlantic to a “text message,” delivered immediately to the Southern Hemisphere, while the oceanic cooling is more like a “postcard,” not felt in Antarctica for another 200 years.
To identify this climate “teleconnection” between Earth’s poles, researchers relied on detailed chemical analyses of more than 1.5 km of Antarctic ice core, including more than 400,000 individual measurements, made in the Ultra-Trace Chemistry Laboratory using a unique continuous flow system and inductively coupled plasma mass spectrometry. Retrieved from the West Antarctic Ice Sheet (WAIS), this ice core sample, known as the WAIS Divide core, was collected by a team including DRI emeritus research professor Kendrick Taylor, Ph.D. Their original research into the connection between the Earth’s polar regions using the WAIS Divide core was first explained in Nature in 2015.
The full text of the study titled “Abrupt ice-age shifts in southern westerly winds and Antarctic climate forced from the north” is available in Nature: https://www.nature.com/articles/s41586-018-0727-5. A full news release from Oregon State University is below.
Continue Reading DRI ice core data illustrates climate “teleconnection” between Earth’s poles during climate changes in the last Ice Age
Nov 13, 2018 | News releases, Research findings
Reno, Nev. (Nov. 13, 2018): A new ice core record from the French Alps shows impacts of fossil fuel emissions in the form of a steep increase in iodine levels during the second half of the 20th century, according to a study released this week by an international team of scientists from the Université Grenoble Alpes-CNRS of France, the Desert Research Institute (DRI) in Reno, Nev., and the University of York in England.
“Model and laboratory studies had suggested that atmospheric iodine should have increased during recent decades as a result of increasing fossil fuel emissions but few long-term records of iodine existed with which to test these model findings, and none in Western Europe where modeled iodine increases were especially pronounced,” said French researcher and lead author Michel Legrand, Ph.D.
Iodine is an important nutrient for human health, key in the formation of thyroid hormones. It is present in ocean waters, and is released into the atmosphere when Iodide (I-) reacts with ozone (03) at the water’s surface. From the atmosphere, iodine is deposited onto Earth’s land surfaces, and absorbed by humans in the foods that we eat.
The new study, published in the Proceedings of the National Academy of Sciences, was initiated after scientists observed a three-fold increase in iodine between 1950 and the 1990s measured in an ice core from the Col du Dome region of France. The core was collected by French scientists and analyzed in 2017 in DRI’s Ultra Trace Ice Core Analysis Laboratory.
Researchers examine an ice core sample drilled from Mont Blanc. Credit: B. Jourdain, L’Institut des Géosciences de l’Environnement.
Although previous modeling simulations had indicated a similar increase in global iodine emissions during the 20th century, this new record provides the first ice core iodine record from outside of the polar regions.
“Iodine has been measured previously in polar ice cores but changes there largely can be attributed to variations in sea ice,” said Joe McConnell, Ph.D., research professor of hydrology and head of DRI’s ice core laboratory. “These variations mask the larger scale trends linked to fossil fuel emissions and changes in ozone chemistry. Our new iodine record extends from 1890 to 2000 and is from the French Alps, a part of the world where there are no sea ice influences.”
As part of this study, more than 120 meters (nearly 400 feet) of ice core from the French Alps was analyzed for iodine and a broad range of chemical species by a group of DRI researchers that included McConnell, Monica Arienzo, Ph.D., Nathan Chellman, and Kelly Gleason, Ph.D., using DRI’s unique continuous analytical system.
The study team then analyzed the ice core record alongside modeling simulations to investigate past atmospheric iodine concentrations and changes in iodine deposition across Europe. According to their results, the observed tripling of iodine levels in the ice during the 1950s to 1990s were caused by increased iodine emissions from the ocean.
An ice core sample is processed in DRI’s Ultra-Trace Ice Core Laboratory in Reno, Nev. Credit: Joe McConnell/DRI.
Ozone in the lower atmosphere acts as an air pollutant and greenhouse gas. Because iodine emissions from the ocean occur when iodine in the water reacts with ozone in the lower atmosphere, the study results indicate that increased ozone levels are increasing the availability of iodine in the atmosphere – and also that iodine is helping to destroy this “bad” ozone.
“Iodine’s role in human health has been recognized for some time – it is an essential part of our diets,” said Lucy Carpenter, Ph.D., Professor with University of York’s Department of Chemistry. “Its role in climate change and air pollution, however, has only been recognized recently and the impact of iodine in the atmosphere is not currently a feature of the climate or air quality models that predict future global environmental changes.”
According to the World Health Organization, iodine deficiency remains a significant health problem in parts of Europe, including France, Italy and certain regions of Spain – regions that now appear to have received a boost in iodine levels in recent years.
“The silver lining in the findings of this study is that the increase in human-caused pollution during the latter half of the 20th century may be leading to an increase in the availability of iodine as an essential nutrient,” Legrand said.
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To view the study, titled Alpine ice evidence of a three-fold increase in atmospheric iodine deposition since 1950 in Europe due to increasing oceanic emissions, published in the journal Proceedings of the National Academy of Sciences on 12 November 2018, please visit: http://www.pnas.org/content/early/2018/11/07/1809867115
Samantha Martin from the University of York contributed to this release.
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. Learn more at dri.edu, and connect with us on social media on Facebook, Instagram and Twitter.
Sep 20, 2018 | News releases, Research findings
Above: A lone researcher is silhouetted by the summer sun, low in the Antarctic sky. Credit: Bradley Markle, UCSB.
Reno, Nev. (Sept. 20, 2018) – In September, new research by a team from the University of California, Santa Barbara, the University of Washington, Columbia University, and the Desert Research Institute (DRI) was published in the journal Nature Geoscience. The study, titled Concomitant variability in high-latitude aerosols, water isotopes and the hydrologic cycle, utilized data provided by Joe McConnell, Ph.D., director of DRI’s Ultra-Trace Chemistry Laboratory in Reno, Nev.
The study explains an observed connection between concentrations of aerosols (small atmospheric particles such as mineral dust and sea-salt) and the ratios of different isotopes of water (variant forms of H20 in which the atoms carry extra neutrons) found in Antarctic ice cores.
Aerosol measurements for this study, which consisted of more than 500,000 measurements of calcium and sodium in 2.1 kilometers (1.3 miles) of Antarctic ice, were made in the Ultra-Trace Chemistry Laboratory using a unique continuous flow system and inductively coupled plasma mass spectrometry. Parts of these aerosol records have been published previously, but they are published in full in the new study. The full news release from U.C. Santa Barbara is below.
These shallow cores help us with the interpretation of the deep one,” explained UC Santa Barbara’s Bradley Markle. Credit: Bradley Markle, UCSB.
Dust, Rain and the Poles
Warmer climates will likely decrease the amount of airborne sediments reaching the poles
By Harrison Tasoff, University of California, Santa Barbara
Every year, the global climate transports billions of tons of dust around the world. These aerosols play a key role in many of Earth’s geological and biological cycles.
For instance, wind blows millions of tons of dust from the Sahara Desert across the Atlantic Ocean, where it fertilizes the Amazon Rainforest. The collective action of billions of trees pumping water from the ground then generates its own weather pattern, affecting the whole of South America.
When climate scientist Bradley Markle, at UC Santa Barbara’s Earth Research Institute, spotted a correlation between the ratios of heavy molecules and the concentration of particulate matter in the Antarctic ice cores he was studying, he immediately set out to uncover the deeper connection. His findings appear in the journal Nature Geoscience.
For decades scientists have been puzzled by the relationship between aerosol concentrations and the ratios of different molecules of water in ice cores, and Markle appears to have finally found the connection. His research increases our understanding of the processes at work in Earth’s atmosphere and could help to improve our climate models.
Markle focuses on understanding how climactic processes concentrate atoms of different weights in certain areas. Consider oxygen, for example. Every oxygen atom has eight positively charged protons. That’s what makes it oxygen. However, the number of neutrally charged neutrons it contains can vary from eight to 10. And the greater the number of neutrons, the heavier the isotope.
Water has one oxygen atom bonded to two hydrogen atoms, so water containing lighter isotopes, like 16O — which has eight neutrons — weighs less than water with heavier ones, like 18O — which has 10. Certain processes affect heavier molecules more than their lighter counterparts, leading to varying distributions of different weights across the globe. So even though 99.7 percent of oxygen on Earth is 16O, slight differences in the ratio between 16O and 18O provide scientists with valuable clues about the planet’s climate. In fact, measurements of these ratios in ice cores underlie our most detailed long records of Earth’s temperature history, Markle explained. They span hundreds of thousands of years before humans started measuring temperature directly.
Researchers examine the ice cores, which are backlit by the sun. Credit: Bradley Markle, UCSB.
Scientists noticed that ice layers with higher ratios of heavy isotopes also contained a greater concentration of trapped aerosols. “And it’s a very unique relationship, too,” Markle said. “It’s very clearly logarithmic … so it seems like it needs a strong, logarithmic process to account for it.
“The correlation between the thing that records the climate (the water isotope ratios) and these aerosols is extremely good,” he continued. “Better than you get in almost anything else in this field.”
Precipitation has the most influence on the percentage of heavy isotopes that make it to high latitudes, since heavier water molecules condense more readily compared to light ones, Markle explained. Warm air holds more moisture than cold air, so as it cools on its way toward the poles, the moisture condenses and preferentially loses the heavier molecules. If the poles become warmer, the air will not cool as much, so a greater number of heavy molecules will make it to higher latitudes. As a result, scientists associate low ratios of heavy isotopes with colder periods in Earth’s history.
Scientists suspected that these climatic conditions impacted the locations these aerosols came from, somehow effecting greater emissions during cooled periods than warm ones. However, years of research had yet to produce a model that fit the data. In addition, source variability is challenging to investigate because it requires looking at myriad factors in many different places. “People have investigated it, and they can’t get the sources to have such large changes in aerosol emissions,” Markle said.
Markle compared aerosol data from the Antarctic ice cores with similarly aged seafloor sediment from the oceans just below South America, which is the dominant source of the airborne dust found in Antarctica. He discovered that aerosol levels in the ocean sediment increased three- to six-fold during the last glacial maximum. However, concentrations in the ice cores soared to levels 20 to 100 times baseline rates. Clearly most of the change seen in the ice cores must be due to factors far from the source of the aerosols.
Then Markle recognized a similarity between the isotope ratios and the aerosol concentrations: The physics of moisture in the atmosphere is driving both of them.
A view of the Antarctic coast from the Southern Ocean. Credit: Bradley Markle, UCSB.
Without aerosols, the world would have no rain. Water vapor needs a surface to condense, or form droplets. This could be a steamy shower window or a fleck of dust floating high in the clouds. In this way, precipitation washes the sky of aerosols. More precipitation between the source of the aerosols and the poles means lower concentrations of aerosols make it to the glaciers, and thus into the ice cores. And more precipitation also leads to lower ratios of heavy isotopes. Markle had discovered the connection.
What’s more, the scouring effect precipitation has on aerosols is exponential, meaning its influence increases the longer, and farther, the aerosols travel from their source. Precisely the sort of relationship Markle needed to match the data.
“This rainout theory ends up solving a whole bunch of things at once,” Markle said. It clarifies the correlation between aerosol concentrations and water isotopes, as well as the greater variability in aerosol levels at the poles than in locations closer to the source of the debris. The effect also explains why dust levels vary more than sea salt levels in the aerosol record: The ocean is closer to Antarctica than the source of dust, so precipitation has less impact on the amount of sea salt that makes it to the West Antarctic ice-sheet.
Markle is cautious about making predictions for our current climate change. “The effect that we saw in the ice cores was a really big effect, but it’s a big effect on multicentury, multimillennium time scales,” Markle said. Other sources of variability may be more prominent over shorter timeframes, he explained.
Nonetheless, warming temperatures would forecast decreasing concentrations of aerosols reaching the Arctic and Antarctic. Since aerosols reflect heat and sunlight, this could exacerbate warming trends over long periods of time. Changes in aerosol distribution could also affect the ocean, since they also contain nutrients and minerals vital to ocean’s food web.
Markle plans to leverage his newfound understanding of these relationships to investigate changes not only in the strength of hydrologic cycle but also in its spatial pattern. “Because the hydrologic cycle is tied to Earth’s temperature gradients, I think we can use these records to understand changes in polar amplification,” he explained. This is the phenomenon where the poles warm more than lower latitudes during climate change.
“This is a big deal in modern climate change,” he added, “and understanding how it has happened in the past would be extremely useful.”
This news release was originally published by the University of California, Santa Barbara. To view the original story, please visit: http://www.news.ucsb.edu/2018/019185/dust-rain-and-poles
To view the study titled Concomitant variability in high-latitude aerosols, water isotopes and the hydrologic cycle, published in Nature Geoscience on 10 September 2018, please visit: https://www.nature.com/articles/s41561-018-0210-9
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Aug 28, 2018 | News releases, Research findings
Above: In semi-arid ecosystems such as the Humboldt-Toiyabe National Forest near Las Vegas, which burned as part of the Carpenter 1 fire during July and August 2013, fuel is limited and fires tend to be short lived and low in peak temperature. New research shows that these fires are more harmful to soils than they initially appear. This photo was taken on January 6, 2015 – approximately 18 months after the wildfire. Credit: Teamrat Ghezzehei, UCM.
New research shows negative effects of fire on soil structure and organic matter
Las Vegas, NV (August 28, 2018): Low-severity wildland fires and prescribed burns have long been presumed by scientists and resource managers to be harmless to soils, but this may not be the case, new research shows.
According to two new studies by a team from the University of California, Merced (UCM) and the Desert Research Institute (DRI), low-severity burns – in which fire moves quickly and soil temperature does not exceed 250oC (482oF) – cause damage to soil structure and organic matter in ways that are not immediately apparent after a fire.
“When you have a high-severity fire, you burn off the organic matter from the soil and the impact is immediate,” said Teamrat Ghezzehei, Ph.D., principal investigator of the two studies and Associate Professor of Environmental Soil Physics at UCM. “In a low-severity fire, the organic matter doesn’t burn off, and there is no visible destruction right away. But the burning weakens the soil structure, and unless you come back at a later time and carefully look at the soil, you wouldn’t notice the damage.”
DRI researcher Markus Berli, Ph.D., Associate Research Professor of Environmental Science, became interested in studying this phenomenon while visiting a burned area near Ely, Nev. in 2009, where he made the unexpected observation that a prescribed, low-severity fire had resulted in soil structure damage in the burned area. He and several colleagues from DRI conducted a follow-up study on another controlled burn in the area, and found that soil structure that appeared to be fine immediately after a fire but deteriorated over the weeks and months that followed. Berli then teamed up with Ghezzehei and a team from UCM that included graduate student Mathew Jian, and Associate Professor Asmeret Asefaw Berhe, Ph.D., to further investigate.
Researcher Markus Berli from the Desert Research Institute examines the soils at a burned area in the Humboldt-Toiyabe National Forest near Las Vegas on January 6, 2015, approximately 18 months after the area burned in the Carpenter 1 fire of 2013. Credit: Teamrat Ghezzehei, UCM.
Soil consists of large and small mineral particles (gravel, sand, silt, and clay) which are bound together by organic matter, water and other materials to form aggregates. When soil aggregates are exposed to severe fires, the organic matter burns, altering the physical structure of the soil and increasing the risk of erosion in burned areas. In low-severity burn areas where organic matter doesn’t experience significant losses, the team wondered if the soil structure was being degraded by another process, such as by the boiling of water held within soil aggregates?
In a study published in AGU Geophysical Research Letters in May 2018, the UCM-DRI team investigated this question, using soil samples from an unburned forest area in Mariposa County, Calif. and from unburned shrubland in Clark County, Nev. to analyze the impacts of low-severity fires on soil structure. They heated soil aggregates to temperatures that simulated the conditions of a low-severity fire (175oC/347oF) over a 15-minute period, then looked for changes in the soil’s internal pore pressure and tensile strength (the force required to pull the aggregate apart).
During the experiment, they observed that pore pressure within the soil aggregates rose to a peak as water boiled and vaporized, then dropped as the bonds in the soil aggregates broke and vapor escaped. Tensile strength measurements showed that the wetter soil aggregates had been weakened more than drier soil samples during this process.
“Our results show that the heat produced by low-severity fires is actually enough to do damage to soil structure, and that the damage is worse if the soils are wet,” Berli explained. “This is important information for resource managers because it implies that prescribed burns and other fires that occur during wetter times of year may be more harmful to soils than fires that occur during dry times.”Next, the research team wondered what the impact of this structural degradation was on the organic matter that the soil structure normally protects. Soil organic matter consists primarily of microbes and decomposing plant tissue, and contributes to the overall stability and water-holding capacity of soils.
In a second study that was published in Frontiers in Environmental Science in late July, the UCM-DRI research team conducted simulated burn experiments to weaken the structure of the soil aggregates, and tested the soils for changes in quality and quantity of several types of organic matter over a 70-day period.
They found that heating of soils led to the release of organic carbon into the atmosphere as CO2 during the weeks and months after the fire, and again found that the highest levels of degradation occurred in soils that were moist. This loss of organic carbon is important for several reasons, Ghezzehei explained.
“The loss of organic matter from soil to the atmosphere directly contributes to climate change, because that carbon is released as CO2,” Ghezzehei said. “Organic matter that is lost due to fires is also the most important reserve of nutrients for soil micro-organisms, and it is the glue that holds soil aggregates together. Once you lose the structure, there are a lot of other things that happen. For example, infiltration becomes slower, you get more runoff, you have erosion.”
Researcher Rose Shillito from DRI collects soil samples in a burned area in the Humboldt-Toiyabe National Forest near Las Vegas on January 6, 2015, approximately 18 months after the area burned in the Carpenter 1 fire of 2013. Credit: Teamrat Ghezzehei, UCM.
Although the research team’s findings showed several detrimental effects of fire on soils, low-severity wildfires and prescribed burns are known to benefit ecosystems in other ways — recycling nutrients back into the soil and getting rid of overgrown vegetation, for example. It is not yet clear whether the negative impacts on soil associated with these low-severity fires outweigh the positives, Berli says, but the team hopes that their research results will help to inform land managers as they manage wildfires and plan prescribed burns.
“There is very little fuel in arid and semi-arid areas, and thus fires tend to be short lived and relatively low in peak temperature,” Ghezzehei said. “In contrast to the hot fires and that burn for days and weeks that we see in the news, these seem to be benign and we usually treat them as such. Our work shows that low-severity fires are not as harmless as they may appear.”
The study, “Soil Structural Degradation During Low‐Severity Burns,” was published on May 31, 2018 in the journal AGU Geophysical Research Letters and is available here: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GL078053.
The study, “Vulnerability of Physically Protected Soil Organic Carbon to Loss Under Low Severity Fires,” was published July 19, 2018 in the journal Frontiers in Environmental Science, and is available here: https://www.frontiersin.org/articles/10.3389/fenvs.2018.00066/full.
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Aug 15, 2018 | News releases, Research findings
Above: Dr. Vera Samburova works in the organic analytical lab at Desert Research Institute, in Reno, Nev., on Tuesday, Feb. 20, 2018.
Photo by Cathleen Allison/Nevada Momentum
Reno, NV (August 15, 2018) – E-cigarettes have become increasingly popular as a smoke-free alternative to conventional tobacco cigarettes, but the health effects of “vaping” on humans have been debated in the scientific and tobacco manufacturing communities. While aldehydes—chemicals like formaldehyde that are known to cause cancer in humans—have been identified in e-cigarette emissions by numerous studies, there has been little agreement about whether such toxins exist in large enough quantities to be harmful to users.
Now, a recently published pilot study by a team of researchers from the Desert Research Institute (DRI) and the University of Nevada, Reno shows that significant amounts of cancer-causing chemicals such as formaldehyde are absorbed by the respiratory tract during a typical vaping session, underscoring the potential health risks posed by vaping.
“Until now, the only research on the respiratory uptake of aldehydes during smoking has been done on conventional cigarette users,” said Vera Samburova, Ph.D., associate research professor in DRI’s Division of Atmospheric Sciences and lead author of the study. “Little is known about this process for e-cigarette use, and understanding the unique risks vaping poses to users is critical in determining toxicological significance.”
Samburova and fellow DRI research professor Andrey Khlystov, Ph.D., have been investigating the health risks associated with e-cigarettes for several years. In 2016, they published findings confirming that dangerous levels of aldehydes are formed during the chemical breakdown of flavored liquids in e-cigarettes and emitted in e-cigarette vapors.
In this study, Samburova and her team estimated e-cigarette users’ exposure to these hazardous chemicals by analyzing the breath of twelve users before and after vaping sessions using a method she and Khlystov have developed over the course of their work together. Through this process, they determined how much the concentration of aldehydes in the breath increased. Researchers then subtracted the concentration of chemicals in exhaled breath from the amount found in the vapors that come directly from the e-cigarette.
The difference, Samburova explains, is absorbed into the user’s lungs.
E-cigarettes in the Organic Analytical Lab at DRI.
“We found that the average concentration of aldehydes in the breath after vaping sessions was about ten and a half times higher than before vaping,” Samburova said. “Beyond that, we saw that the concentration of chemicals like formaldehyde in the breath after vaping was hundreds of times lower than what is found in the direct e-cigarette vapors, which suggests that a significant amount is being retained in the user’s respiratory tract.”
The research team took care to ensure that the test conditions of the study mirrored real-life vaping sessions as much as possible. Most participants used their own e-cigarette devices during the study, used e-liquid flavors that were familiar to them, and inhaled for the amount of time that they ordinarily would, which allowed the research team to understand how e-cigarettes are typically used by regular users. Because they tested “normal” vaping experiences, researchers confirmed that the high concentrations of aldehydes found in other studies aren’t limited to laboratory conditions.
“Our new pilot study underlines the potential health risk associated with the aldehydes generated by e-cigarettes,” said Samburova. “In the future, e-cigarette aldehyde exposure absolutely needs to be studied with a larger set of participants.”
The study, “Aldehydes in Exhaled Breath during E-Cigarette Vaping: Pilot Study Results,” was published on August 7th in the journal Toxics and is available here: https://www.mdpi.com/2305-6304/6/3/46/htm#app1-toxics-06-00046. DOI: 10.3390/toxics6030046
This research was independently funded by DRI and conducted in DRI’s Organic Analytical Laboratory located in Reno, Nevada. For more information about the Organic Analytical Lab, visit: https://www.dri.edu/labs/oal/.
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Jul 20, 2018 | News releases, Research findings
Stone tool assemblage recovered from the Gault Site. Credit: Produced by N Velchoff, The Gault School of Archaeological Research.
Luminescence dating confirms human presence in North America prior to 16 thousand years ago, earlier than previously thought
July 20, 2018 (Reno, NV) – For decades, researchers believed the Western Hemisphere was settled by humans roughly 13,500 years ago, a theory based largely upon the widespread distribution of Clovis artifacts dated to that time. Clovis artifacts are distinctive prehistoric stone tools so named because they were initially found near Clovis, New Mexico, in the 1920s but have since been identified throughout North and South America.
In recent years, though, archaeological evidence has increasingly called into question the idea of “Clovis First.”Now, a study published by a teamincluding DRI’s Kathleen Rodrigues, Ph.D. student, and Amanda Keen-Zebert, Ph.D., associate research professor, has dated a significant assemblage of stone artifacts to 16-20,000 years of age, pushing back the timeline of the first human inhabitants of North America before Clovisby at least 2,500 years.
Significantly, this research identifies a previously unknown, early projectile point technology unrelated to Clovis, which suggests that Clovis technology spread across an already well-established, indigenous population.
“These projectile points are unique. We haven’t found anything else like them,” said Tom Williams, Ph.D., Postdoctoral Research Associate in the Department of Anthropology at Texas State University and lead author of the study. “Combine that with the ages and the fact that it underlies a Clovis component, and the Gault site provides a fantastic opportunity to study the earliest human occupants in the Americas.”
The research team identified the artifacts at the Gault Site in Central Texas, an extensive archaeological site with evidence of continuous human occupation. The presence of Clovis technology at the site is well-documented, but excavations below the deposits containing Clovis artifacts revealed well-stratified sediments containing artifacts distinctly different from Clovis.
To determine the ages of these artifacts, Rodrigues, Keen-Zebert, and colleagues used a process called optically stimulated luminescence (OSL) dating on the sediments surrounding them. In OSL, researchers expose minerals that have long been buried under sediment layers to light or heat, which causes the minerals to release trapped potassium, uranium, and thorium electrons that have accumulated over time due to exposure to ambient, naturally occurring radiation.When the trapped electrons are released, they emit photons of light which can be measured to determine the amount of time that has elapsed since the materials were last exposed to heat or sunlight.
“The fluvial nature of the sediments deposited at the Gault Site have created a poor environment for preservation of organic materials, so radiocarbon dating has not been a useful technique to apply in this region,” said Kathleen Rodrigues, graduate research assistant in DRI’s Division of Earth and Ecosystem Sciences. “This made luminescence dating a natural choice for dating the archaeological materials here. We are really pleased with the quality of the results that we have achieved.”
Jayme Blaschke of the Texas State University Office of Media Relations contributed to this release.
The Desert Research Institute (DRI) is a recognized world leader in investigating the effects of natural and human-induced environmental change and advancing technologies aimed at assessing a changing planet. For more than 50 years DRI research faculty, students, and staff have applied scientific understanding to support the effective management of natural resources while meeting Nevada’s needs for economic diversification and science-based educational opportunities. With campuses in Reno and Las Vegas, DRI serves as the non-profit environmental research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
May 14, 2018 | News releases, Research findings
Dr. Monica Arienzo inspects an ice core sample in the ice core lab at the Desert Research Institute in Reno, Nev. Photo credit: DRI.
Reno, NV (May 14, 2018): To learn about the rise and fall of ancient European civilizations, researchers sometimes find clues in unlikely places: deep inside of the Greenland ice sheet, for example.
Thousands of years ago, during the height of the ancient Greek and Roman empires, lead emissions from sources such as the mining and smelting of lead-silver ores in Europe drifted with the winds over the ocean to Greenland – a distance of more than 2800 miles (4600 km) – and settled onto the ice. Year after year, as fallen snow added layers to the ice sheet, lead emissions were captured along with dust and other airborne particles and became part of the ice-core record that scientists use today to learn about conditions of the past.
In a new study published in PNAS, a team of scientists, archaeologists and economists from the Desert Research Institute (DRI), the University of Oxford, NILU – Norwegian Institute for Air Research and the University of Copenhagen used ice samples from the North Greenland Ice Core Project (NGRIP) to measure, date and analyze European lead emissions that were captured in Greenland ice between 1100 BC and AD 800. Their results provide new insight for historians about how European civilizations and their economies fared over time.
“Our record of sub-annually resolved, accurately dated measurements in the ice core starts in 1100 BC during the late Iron Age and extends through antiquity and late antiquity to the early Middle Ages in Europe – a period that included the rise and fall of the Greek and Roman civilizations,” said the study’s lead author Joe McConnell, Ph.D., Research Professor of Hydrology at DRI. “We found that lead pollution in Greenland very closely tracked known plagues, wars, social unrest and imperial expansions during European antiquity.”
Map showing location of NGRIP ice core in relation to Roman lead/silver mines. Credit: DRI.
A previous study from the mid-1990s examined lead levels in Greenland ice using only 18 measurements between 1100 BC and AD 800; the new study provides a much more complete record that included more than 21,000 precise lead and other chemical measurements to develop an accurately dated, continuous record for the same 1900-year period.
To determine the magnitude of European emissions from the lead pollution levels measured in the Greenland ice, the team used state-of-the-art atmospheric transport model simulations.
“We believe this is the first time such detailed modeling has been used to interpret an ice-core record of human-made pollution and identify the most likely source region of the pollution,” said co-author Andreas Stohl, Ph.D., Senior Scientist at NILU.
Most of the lead emissions from this time period are believed to have been linked to the production of silver, which was a key component of currency.
“Because most of the emissions during these periods resulted from mining and smelting of lead-silver ores, lead emissions can be seen as a proxy or indicator of overall economic activity,” McConnell explained.
Using their detailed ice-core chronology, the research team looked for linkages between lead emissions and significant historical events. Their results show that lead pollution emissions began to rise as early as 900 BC, as Phoenicians expanded their trading routes into the western Mediterranean. Lead emissions accelerated during a period of increased mining activity by the Carthaginians and Romans primarily in the Iberian Peninsula and reached a maximum under the Roman Empire.
Chronology of European lead emissions that were captured in Greenland ice between 1100 BC and AD 800 in relation to major historic events. Credit: DRI.
The team’s extensive measurements provide a different picture of ancient economic activity than previous research had provided. Some historians, for example, had argued that the sparse Greenland lead record provided evidence of better economic performance during the Roman Republic than during the Roman Empire.
According to the findings of this study, the highest sustained levels of lead pollution emissions coincided with the height of the Roman Empire during the 1st and 2nd centuries AD, a period of economic prosperity known as the Pax Romana. The record also shows that lead emissions were very low during the last 80 years of the Roman Republic, a period known as the Crisis of the Roman Republic.
“The nearly four-fold higher lead emissions during the first two centuries of the Roman Empire compared to the last decades of the Roman Republic indicate substantial economic growth under Imperial rule,” said coauthor Andrew Wilson, Professor of the Archaeology of the Roman Empire at Oxford.
The team also found that lead emissions rose and fell along with wars and political instability, particularly during the Roman Republic, and took sharp dives when two major plagues struck the Roman Empire in the 2nd and 3rd centuries. The first, called the Antonine Plague, was probably smallpox. The second, called the Plague of Cyprian, struck during a period of political instability called the third-century crisis.
“The great Antonine Plague struck the Roman Empire in AD 165 and lasted at least 15 years. The high lead emissions of the Pax Romana ended exactly at that time and didn’t recover until the early Middle Ages more than 500 years later,” Wilson explained.
The research team for this study included ice-core specialists, atmospheric scientists, archaeologists, and economic historians – an unusual combination of expertise.
“Working with such a diverse team was a unique experience in my career as a scientist,” McConnell said. “I think that our results show that there can be great value in collaborating across disciplines.”
Analysis and interpretation of archived NGRIP2 ice-core samples were supported by the John Fell Oxford University Press Research Fund and All Souls College, Oxford, as well as the Desert Research Institute.
The project team included an interdisciplinary team of researchers, including (left to right) Dr. Audrey Yau, ice core specialist and former DRI post-doc; Dr. Monica Arienzo, ice core specialist, DRI; Elisabeth Thompson, doctoral student, Oxford University; Professor Andrew Wilson, historian, Oxford University; and Professor Joe McConnell, ice core specialist, DRI.
Apr 24, 2018 | News releases, Research findings
Above: Cave opening at the Mule Springs Rockshelter in southern Nevada’s Spring Mountain Range. Credit: Jeffrey Wedding, DRI.
Las Vegas, NV (April 24, 2018): If you want to know about your ancestors today, you can send a little saliva to a company where – for a fee – they will analyze your DNA and tell you where you come from. For scientists trying to find out about ancient peoples, however, the challenge is more complex.
Research published in the journal PLOS ONE by a team of archaeologists and microbiologists from Nevada’s Desert Research Institute (DRI) and Southern Illinois University Carbondale (SIU) showcases the use of modern research methods to uncover clues about the genetic ancestry of Native Americans who inhabited the Desert Southwest during the last thousand years.
“We were surprised by the consistency with which we were able to recover intact human DNA from a common type of plant-based artifact,” explained co-principal investigator Duane Moser, Ph.D., an associate research professor of microbiology at DRI and director of DRI’s Environmental Microbiology Laboratory.
During the Late Holocene Epoch, which began 12,000 to 11,500 years ago and continues through the present, occupants of the Mule Spring Rockshelter in the foothills of the Spring Mountains of southern Nevada commonly gathered agave and yucca plants for food. The artichoke-like hearts and inner leaves of the plants were roasted then chewed to consume the sweet fleshy pulp. This left wads of stringy fibers called ‘quids,’ which were spit out and left behind.
In the late 1960s, researchers from DRI and the University of Nevada, Las Vegas (UNLV) led by Richard Brooks, recovered thousands of quids at the rockshelter. Put into storage for half a century without any consideration for DNA preservation, a DRI-led research team decided to re-examine the quid specimens as possible repositories for ancient DNA.
“The quid’s coarse texture is excellent for capturing skin cells from the mouth, making them the equivalent of the modern-day cheek swab,” explained Susan Edwards, an associate research archaeologist at DRI and co-principal investigator who first thought of applying DNA extraction techniques to the quid samples.
A wad of stringy agave plant fibers commonly called ‘quids’. Credit: DRI
The research team used laboratory and computational resources at DRI’s Southern Nevada Science Center in Las Vegas, and later at SIU, to identify changes in the mitochondrial DNA sequences that are maintained in ancestrally related populations called haplogroups. These haplogroups can then be compared to Native American tribes and other ancient DNA lineages.
The study showed that the Mule Spring Rockshelter quid specimens ranged in age from about 350 to 980 years old. Because Mule Spring Rockshelter sits at a crossroads between the southern Great Basin, the Mojave Desert, and the Southwest Puebloan cultures, these results may provide a better timeline for an important but contentiously debated event in human history known as the Numic Spread.
Today’s Numic people contend they have always been here, a position some scientists readily support. However, some evidence suggests that Numic-speaking ancestors of contemporary native peoples spread from southern California throughout the Great Basin about 500 to 700 years ago; a date range which overlaps with the current study. Other studies suggest a much earlier arrival.
This research marks only the second time that scientists have been able to sequence human DNA from plant-based artifacts, expanding upon an approach utilized by Steven LeBlanc of Harvard University.
“Since these materials were also radiocarbon dated, in essence they provide a time-resolved hotel registry for this unique site over a period of hundreds of years,” added Moser.
As an added benefit of utilizing DNA from quid samples (rather than from more traditional sources such as bones or teeth), the research team found that they were able to obtain the information they needed while being respectful of cultural sensitivities.
“The distinct advantage of this genetic technique, is that it does not require the sampling of human remains” said Scott Hamilton-Brehm, lead author on the study and assistant professor of microbiology at SIU who completed his postdoctoral research at DRI.
In the future, the team hopes to continue this work by targeting additional quids from the Mule Spring Rockshelter collection, with the possibility of corroborating evidence of older dates for habitation of the site suggested by prior studies of more traditional cultural artifacts. Plans are in the works to perform similar studies on quids from other Great Basin sites to glean additional information about the movements of ancient peoples and utilize more powerful analytical approaches to obtain greater DNA sequence coverage than was obtained by this pilot study.
“We look forward to learning more about Native American presence in the Great Basin and Southwest area, and how the data compares over time,” added Lidia Hristova, a graduate of the UNLV Anthropology Program who conducted much of the hands-on DNA extraction from the samples while working as an undergraduate research assistant at DRI and studying at UNLV.
The full study, “Ancient human mitochondrial DNA and radiocarbon analysis of archived quids from the Mule Spring Rockshelter, Nevada, USA,” is available online from PLOS ONE: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0194223
Mule Spring Rockshelter is a protected cultural resource located on BLM-managed lands. DRI access to the Mule Spring collection was granted under permit and loan agreement.
Tim Crosby, Communications and Marketing Strategist at SIU Carbondale contributed to this press release.
Additional photos available upon request.
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The Desert Research Institute (DRI) is a recognized world leader in investigating the effects of natural and human-induced environmental change and advancing technologies aimed at assessing a changing planet. For more than 50 years DRI research faculty, students, and staff have applied scientific understanding to support the effective management of natural resources while meeting Nevada’s needs for economic diversification and science-based educational opportunities. With campuses in Reno and Las Vegas, DRI serves as the non-profit environmental research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Mar 20, 2018 | News releases, Research findings
Above: Researchers Joshua Sackett (left) and Duane Moser (right) of DRI help National Park Service officials move scaffolding infrastructure during a routine sampling visit to Devils Hole on December 13, 2014. Credit: Jonathan Eisen.
DRI study finds key differences between artificial habitat and the real Devils Hole
Las Vegas, NV (Tuesday, March 20, 2018): In a first-of-its kind study of comparing the microbiology of Devils Hole with that of a constructed scale replica at the Ash Meadows Fish Conservation Facility (AMFCF), a team of scientists from the Desert Research Institute (DRI) in Las Vegas discovered key differences in nutrient levels and species composition that may be impacting the ability of the highly endangered Devils Hole Pupfish (Cyprinodon diabolis) to survive in captivity.
“We were interested in taking a closer look at the chemical and biological factors that control productivity at both sites,” said Duane Moser, Ph.D., an associate research professor of microbiology at DRI who has been involved with research at Devils Hole since 2008. “In studying both, we could gain some insights into how well the artificial refuge actually replicates Devils Hole, and in turn, offer recommendations for ways to make the refuge a better habitat for the pupfish.”
Devils Hole Pupfish (population 115 in autumn 2017) are an iridescent blue, one-inch-long pupfish. They are native only to Devils Hole, an isolated water-filled cavern of unknown depth located in a detached unit of Death Valley National Park within the Ash Meadows National Wildlife Refuge in Amargosa Valley, Nevada. Devils Hole is an extreme environment, with water temperatures and dissolved oxygen concentrations near their lethal limits for most fishes.
Since 2013, scientists have been trying to establish a backup population of these endangered fish in a constructed tank at the AMFCF, which is located a short distance west of Devils Hole. Although the facility was designed to match the climate, water chemistry and physical dimensions of an area of shallow shelf habitat in Devils Hole, the pupfish have had only limited success reproducing and surviving in this artificial environment.
In 2015, Moser and a team of researchers from DRI set out to learn if there were other factors that might be impacting the success of these fish. Their new study, published in the March edition of PLOS One, characterizes and compares water chemistry and microbial communities between Devils Hole and the AMFCF.
Although water temperature and dissolved oxygen at the AMFCF are intentionally maintained at values that are slightly lower and higher, respectively, from those of Devils Hole, this work shows that the nutrient balance between the two sites is also very different, with AMFCF being strongly nitrogen limited – about five times lower than that of Devils Hole.
In the microbial communities, which contribute to the distribution and availability of dissolved nutrients in the water and are also a food source for the pupfish, the research team discovered more than 2,000 microbial species from 44 distinct phyla present in the water at Devils Hole. They detected similar levels of species diversity at AMFCF, but found that different bacterial phyla were dominant at each site. These differences may relate to the observed differences in nitrogen concentrations.
“Nitrogen levels have an effect on the types of organisms that you’ll find, and the types of metabolisms that they have,” said Joshua Sackett, a graduate research assistant with the Desert Research Institute and doctoral student in the School of Life Sciences at the University of Nevada, Las Vegas. “We found a lot fewer of at least one major category of primary producers – the cyanobacteria – in the AMFCF compared to Devils Hole, and we think that’s due to differences in nutrient concentration.”
One of the strengths of the comparative power of this study is that the data from each site were gathered on the same day. This study highlights the potential importance of considering water chemistry and microbiology when constructing artificial fish habitats – and the team hopes that the information will provide a valuable contribution to the continued survival of the Devils Hole Pupfish in captivity.
“This work revealed very different microbial populations, which we infer might correspond to large differences in nutrient dynamics between the sites – especially in terms of nitrogen,” Moser said. “Consequently, some relatively modest tweaks in how the refuge is operated could potentially improve the prospects for continued survival of one of Earth’s most imperiled fishes.”
The full version of the study – A comparative study of prokaryotic diversity and physicochemical characteristics of Devils Hole and the Ash Meadows Fish Conservation Facility, a constructed analog – is available online: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0194404
For more information about DRI, visit www.dri.edu
Photo caption: Researchers Joshua Sackett (left) and Duane Moser (right) of DRI help National Park Service officials move scaffolding infrastructure during a routine sampling visit to Devils Hole on December 13, 2014. Credit: Jonathan Eisen.
Additional photos are available upon request.
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The Desert Research Institute (DRI) is a recognized world leader in investigating the effects of natural and human-induced environmental change and advancing technologies aimed at assessing a changing planet. For more than 50 years DRI research faculty, students, and staff have applied scientific understanding to support the effective management of natural resources while meeting Nevada’s needs for economic diversification and science-based educational opportunities. With campuses in Reno and Las Vegas, DRI serves as the non-profit environmental research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Mar 14, 2018 | News releases, Research findings
Detailed photographs help local scientists understand regional storms, collect weather data
Reno, NV (Wednesday, March 14, 2018): No two snow crystals are alike, an old saying goes – and this winter, students, and adults from across the Reno-Tahoe region are helping researchers from the Desert Research Institute (DRI) discover exactly what the unique shape of each freshly-fallen snowflake means for Nevada’s changing climate.
As part of a new citizen science project called “Stories in the Snow” (storiesinthesnow.org), DRI researchers are enlisting help from a quickly-growing network of students and volunteers in the Reno-Tahoe region to collect photographs of snow crystals each time it snows.
To date, the project has collected more than 400 photographs and data points from around the region, including more than 40 images from a recent storm that hit Reno-Tahoe in early March. In April, the research team will begin analysis of the data that has been collected this winter.
“To participate, all you need is a smartphone, a magnifying lens, and a flake of freshly fallen snow,” said Meghan Collins, education lead for the Stories in the Snow program and Assistant Research Scientist of Environmental Science at DRI. “We have partnered with 15 classes from schools in the local area and several educational non-profits. We are really excited to get students and community members involved in studying our snow and learning about climate science in our region.”
Project participants use a smartphone and data collection kit (available through the Stories in the Snow crowdfunding site) to capture up-close photographs of snowflakes, then submit the photos along with weather data on time, temperature and location to a DRI research team through the Citizen Science Lake Tahoe mobile app. The app, which was developed in partnership with the U.C. Davis Tahoe Environmental Research Center (TERC), is available for iPhone and Andriod operating systems. Following the Tom’s Shoes philanthropic model, each snowflake picture kit purchased through the project’s crowdfunding site provides a one-to-one matching donation of Stories in the Snow kits and training for local students.
By combining the photographs with common weather information on the time and location from which each snow crystal image was captured, DRI atmospheric research teams are learning about the temperature and water content of winter storm clouds. They are using the pictures and the weather data to better understand how snow storms in our region form and how warmer winters are impacting cloud physics and snow levels.
“We want to unravel what goes on in the clouds as a storm moves over the Sierra Crest and through our region,” said Frank McDonough, research lead for the Stories in the Snow project and associate research professor of atmospheric science at DRI. “The ice crystals tell us a lot about what happened during each snowflake’s journey – from how it first formed in the cloud all the way to how early it might melt and where it could land.”
From star-shaped “dendrites” too pointy “needles” and hexagonal “plates,” the shape and condition of each flake tells a unique story, McDonough explained. And if a flake appears covered in tiny, frozen droplets called “rime”, that is especially interesting to the research team – with possible implications for the aviation industry including research into airplane wing icing.
“If you see a snowflake with rime, you know that cloud had sub-freezing liquid water drops in it,” McDonough said. “Under those conditions, if an airplane flies through, the water droplets freeze on the airplane just like they freeze on the ice crystals. In extreme cases, the airplane can’t fly. Our main goal is to just understand clouds that exist below freezing, and what goes on in them when the water is present or absent.”
DRI initially piloted the Stories in the Snow program in several area schools during the winter of 2016-17 and launched a successful crowdfunding campaign to continue the project in October 2017. Now halfway through the 2017-18 season, Stories in the Snow is working in cooperation with teachers at ten local schools and three educational non-profits from the Reno-Tahoe region to enlist participation from students. They have also distributed more than 75 kits to other interested members of the public.
Data collected by the Stories in the Snow program is being used to support numerous projects, including improvements to climate and weather prediction models, validation of radar and satellite precipitation data, and data and insight for highway snow removal crews, avalanche forecasters, and water use planning groups. The research team also plans to make the data available to the public, so that any student or science-minded citizen can conduct their own investigations.
“If an amateur scientist wants to do a study on snowflakes, to see if they look different in March than in January, for example, we are excited to have them do that,” McDonough said. “We want the community to have access to the data. That’s the whole point with citizen science – giving people the opportunity to use these crystal images for their own projects, or just their own enjoyment.”
Stories in the Snow is supported during the 2017-2018 winter season by the Truckee-Tahoe Community Foundation and Nevada Space Grant. For more information about the Stories in the Snow program, please visit http://storiesinthesnow.org, or follow along on Facebook (@storiesinthesnow) or Instagram (@storiesinthesnow).
Additional photos available on Flickr: https://flic.kr/s/aHsmfQxuZL
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The Desert Research Institute (DRI) is a recognized world leader in investigating the effects of natural and human-induced environmental change and advancing technologies aimed at assessing a changing planet. For more than 50 years DRI research faculty, students, and staff have applied scientific understanding to support the effective management of natural resources while meeting Nevada’s needs for economic diversification and science-based educational opportunities. With campuses in Reno and Las Vegas, DRI serves as the non-profit environmental research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Feb 1, 2018 | News releases, Research findings
To a casual observer, desert lands may appear a barren vista of sand and soil, sparsely dotted with shrubbery and cacti but, in reality, they are lush with microscopic plants: lichens, mosses, and cyanobacteria. There isn’t an inch of soil that is without these organisms.
“These organisms are a critical component of the desert ecosystem: they stabilize soils against erosion and provide essential nutrients to plants,” says NEXUS scientist Dr. Henry Sun, a research microbiologist at the Desert Research Institute (DRI).
These coverings-known as cryptogamic crusts-while providing essential ecosystem services, are also very fragile. Both the installation of solar farms and regular maintenance activities can disturb and remove this biological layer. “Such activities can destroy the crusts and result in increased dust emission,” Sun says. “And, once destroyed, they take decades to recover.”
Consequently, Sun and his graduate student, Lynda Burns, are trying to understand the impacts that large scale solar farms will have on this component of desert ecosystems and how to develop mitigation strategies to help prevent, or remediate any damage. “The goal of our research is to know the vulnerabilities of the organisms that build these protective crusts and to use the information to guide future restoration mitigation efforts in the context of solar plant impacts,” Sun says.
Banking Biology
The presence of these non-flowering plants is a key indicator of a healthy desert ecosystem. As well as forming a protective soil crust, and a barrier to erosion, they also provide nutrients to plants, mediate the transfer of water and provide a base for seed germination and plant growth. In addition, the cyanobacteria can convert the nitrogen in the atmosphere into compounds that act as fertilizers for other plants, via a process called nitrogen fixation. “So you fix nitrogen using solar energy into a form that is available to plants,” Sun says.
Recognizing the importance of these crusts, and also their vulnerabilities, scientists have been investigating how to protect them. One suggested approach has been to harvest the crusts prior to a disturbance such as the installation of a solar farm, and save them. Once the construction is complete, the researchers’ suggestion is then to use the preserved crusts to inoculate the soil and aid in restoring the new crust.
The desert can prove a harsh environment for plants with temperatures and rainfall fluctuating between extremes. Also, a process called photochemical oxidation, facilitated by the sun’s ultraviolet rays can result in reactive oxygen species that are extremely damaging to life. “For this strategy to be effective, we need to know if the organisms lose vitality during storage, how long they would survive, and how to help them survive and thrive once they’ve been re-introduced to the desert habitat,” Sun says.
The scientific community does not yet know the answers to such questions and it was a knowledge gap that the NEXUS team set out to close. They began by collecting and saving the organisms in the soil crust and set about trying to understand how long those samples could survive and whether they could be successfully reintroduced to the desert environment. “There were two questions we’re trying to answer,” Sun says. “One, whether you can store the organisms and, two, when you reintroduce them what can we do to help them re-establish?”
Putting Crusts to the Test
In the lab, the scientists started their investigations by storing lichen samples from the Mojave Desert for different periods of time. In their natural habitat the lichens in the crusts alternate between drying out and hydration. During the desiccation process, they suffer from cellular damage but once they are hydrated repair and growth is possible. In their experiments, the researchers watered the stored samples and then monitored their recovery. “Healthy specimens become active within a minute of watering and compromised lichens go through a period of repair before they become productive,” Sun says. The researchers assumed that those lichens that showed no activity after 8 hours were dead.
Using this methodology, the scientists found that lichens can be stored dry at room temperature in ambient air for up to a year without any significant decline in vitality. One-year old samples showed similar behavior to fresh samples: once they were given water they were ready to use light energy and photosynthesize. Three and even ten-year-old samples were weaker and it would take them between 25 and 200 minutes to restore photosynthesis after the addition of water.
The scientists then attempted to determine how ultraviolet (UV) rays would impact the lichens when they were reintroduced back into the desert. The crust lichens protect themselves from UV light by synthesizing compounds that create a screen that blocks the harsh rays. Even when the researchers put intense UV source as close as 25 centimeters away for one week the lichens suffered only minor damage. “It was well within their ability to repair,” Sun says. “This level of ionizing radiation resistance is unparalleled in the microbial world.”
The scientists did find, however, that the lichens were vulnerable to high concentrations of ozone. Fumigation in ozone for long periods caused photochemical oxidation, killing Collema, a cyanobacterial lichen, and severely damaging Placidium, a green algal lichen. Previous studies on the stress tolerance of crust-forming organisms considered only the impacts of UV radiation and desiccation. “Our work showed that photochemical oxidation presents a more severe stress than UV and desiccation,” Sun says. “And this has implications for crust storage and restoration.”
Given the evidence that the crust lichens are primarily vulnerable to oxidation, Sun recommends that the samples be stored in a non-oxidizing gas, such as nitrogen, instead of ambient atmosphere, to minimize oxidative stress. In the field, amending the soil with antioxidants could protect the newly restored “seed” organisms from oxidation and thereby help them grow faster. Both the ability of the organisms to be stored and their ability to survive typical desert conditions bodes well for the future, Sun says. “The research suggests that crust restoration is feasible and should be considered by land managers and solar companies,” Sun says.
This story was written by Jane Palmer and was originally published by the Solar-Energy-Water-Environment Nexus Project. For more information about the Nexus Project, visit: https://solarnexus.epscorspo.nevada.edu/
The Desert Research Institute (DRI) is a recognized world leader in investigating the effects of natural and human-induced environmental change and advancing technologies aimed at assessing a changing planet. For more than 50 years DRI research faculty, students, and staff have applied scientific understanding to support the effective management of natural resources while meeting Nevada’s needs for economic diversification and science-based educational opportunities. With campuses in Reno and Las Vegas, DRI serves as the non-profit environmental research arm of the Nevada System of Higher Education. For more information, visit www.dri.edu.
