Jan 7, 2018 | News releases, Research findings
Above: From the east side of Washoe Lake, the view of Slide Mountain and Mount Rose on January 7, 2018, showed the effects of the ongoing snow drought. Warm wet and dry periods in November and a dry period in December created snow drought conditions throughout the region. Credit Benjamin Hatchett, DRI.
Reno, NV (Wednesday, January 17, 2018): The Lake Tahoe Basin and northern Sierra Nevada are currently experiencing a condition known as snow drought, according to new research and data from scientists at the Desert Research Institute (DRI). Snow droughts, or periods of below-normal snowpack, occur when abnormally warm storms or abnormally dry climate conditions prevent mountain snowpack from accumulating.
“As of early January, the snowpack in the Lake Tahoe Basin was only 28 percent of normal,” said Benjamin Hatchett, Ph.D., a postdoctoral researcher with DRI’s Division of Atmospheric Sciences. “We experienced warm wet and dry periods in November and a dry period in December that has created snow drought conditions throughout the region, followed by warm, rainy weather so far in January that has caused snowpack levels to decline further, especially at low elevation sites.”
Snow droughts have become increasingly common in the Sierra Nevada and Cascade mountains in recent years, as warming temperatures push snow lines higher up mountainsides and cause more precipitation to fall as rain.
Hatchett, an avid backcountry skier, began to notice the trend several years ago and recently published research outlining an approximately 1,200-foot rise in the winter snow levels over the last ten years across the northern Sierra Nevada.
Looking deeper into the rising snow levels and a general continued lack of snow in their local region, Hatchett and fellow DRI climate researcher Daniel McEvoy, Ph.D., an assistant research professor of climatology and regional climatologist at DRI’s Western Regional Climate Center (WRCC), sought to expand upon the little that is currently known about snow droughts and their impacts to local watersheds and economies.
In a new study recently published in the journal Earth Interactions, Hatchett and McEvoy explored the root causes of snow droughts in the northern Sierra Nevada, and investigate how snow droughts evolve throughout a winter season. To do this, they used hourly, daily and monthly data to analyze the progression of eight historic snow droughts that occurred in the northern Sierra Nevada between 1951 and 2017.
“We were interested in looking at the different pathways that can lead to a snow drought, and the different implications that each pathway has for mountain systems,” McEvoy explained.
The snow drought of 2017/2018 as observed at Fallen Leaf Lake, Calif. and the Central Sierra Snow Lab in Soda Springs, Calif. Map created by ClimateEngine.org – Powered by Google Earth Engine. Credit Benjamin Hatchett, DRI.
Previous research has used April 1st (the date that snowpack levels, measured as snow water equivalent or SWE, in the Sierra Nevada typically reach a maximum) as the primary date for calculating snow drought, and classified each snow drought as one of two types, warm or dry. “Warm snow drought” years were characterized by above-average levels of precipitation and below-average snow accumulation (SWE); “Dry snow drought” years were characterized by below-average levels of precipitation and below-average snow accumulation (SWE).
Hatchett and McEvoy’s work expanded upon these concepts by examining the progression of snow droughts throughout the entire winter season.
Their results illustrate that each snow drought originates and develops along a different timeline, with some beginning early in the season and some not appearing until later. Snow droughts often occurred as a result of frequent rain-on-snow events, low precipitation years, and persistent dry periods with warmer than normal temperatures. The severity of each snow drought changed throughout the season, and effects were different at different elevations.
“We learned that if you just look at snow levels on April 1st, you miss out on a lot of important information,” McEvoy said. “For example, if you are in a snow drought all winter long and come out of it right at the end due to a few big storms, there are probably implications to that.”
Sometimes, McEvoy explained, snow droughts were found to occur in years with above-average precipitation. For example, in 1997, a powerful atmospheric river storm event led to record-breaking flooding throughout the region – but much of the moisture arrived as rain rather than snow, with detrimental effects on the snowpack.
Climate change is likely to make snow drought an even more common phenomenon in the future, said Hatchett, as temperatures in the northern Sierra Nevada are expected to continue warming.
“There has always been an occasional snow drought year in the mountains, but that was typically the ‘dry’ type of snow drought caused by lack of precipitation,” Hatchett said. “As the climate grows warmer and more precipitation falls as rain instead of snow, we are seeing that we can have an average or above-average precipitation year and still have a well below-average snowpack.”
The implications of snow drought have not yet been studied extensively, but may include impacts to water resources, snowmelt runoff, flooding, soil moisture, tree mortality, ecological system health, fuel moisture levels that drive fire danger, human recreation, and much more. In regions such as the Lake Tahoe Basin, where mountain snowpack sustains wildlife, ecosystems, local economies, and provides crucial water resources to downstream communities throughout the year, the impacts of snow droughts could be enormous.
The last four winters, Hatchett and McEvoy noted, have all exhibited some degree of snow drought in the northern Sierra Nevada. Even the recent huge winter of 2016/17, which ended with far above-average snowpack levels (205% of the long-term median on April 1, 2017 in the Lake Tahoe Basin), began with a period of early-season snow drought during a dry November. This winter has been no exception, with snow drought taking hold over low elevation areas in November, and moving to higher elevation sites in December.
Only time will tell how the 2017/2018 winter season will end, but in the meantime, snow drought is affecting the region in ways that have not yet been fully quantified.
Hatchet and McEvoy hope that their research will prompt further investigations into the potentially devastating impacts of snow drought, and will help to inform regional climate adaptation planning efforts.
“We spend a lot of time going out and skiing, climbing, and hiking in the mountains, which is what inspired us to study these things,” Hatchett said. “We’re seeing and experiencing snow drought first-hand, and we have to quantify it and understand it because these are changing patterns on the landscape that will have massive implications for the mountain environments that we experience each day and the mountain communities that we live in.”
The full version of the study—“Exploring the Origins of snow drought in the northern Sierra Nevada, California”—is available online at –http://journals.ametsoc.org/doi/10.1175/EI-D-17-0027.1
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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.
Dec 7, 2017 | News releases, Research findings
Reno, NV (Thursday, December 7, 2017): Working with large environmental datasets is a complex and time-consuming endeavor, often requiring huge amounts of data storage, specialized high-performance computers and technical knowledge. Climate Engine (ClimateEngine.org), a new, free web-based application created by a team of scientists at the Desert Research Institute (DRI), University of Idaho, and Google is aiming to change all of that.
New research published and featured on the cover of the November issue of the Bulletin of the American Meteorological Society (BAMS) outlines how Climate Engine improves the accessibility of climate and weather data by allowing users to create on-demand maps or graphs of various earth observation datasets using a standard web browser. Datasets are stored and processed in the cloud on the Google Earth Engine platform, eliminating the need for users to download, store and process large data files on their computers.
Climate Engine provides access to a variety of geospatial datasets that track vegetation, snow and water across the planet, as well as climate datasets that track temperature, precipitation and winds.
One of the web application’s greatest strengths, according to Dr. Justin Huntington, co-principal investigator of the Climate Engine project and associate research professor of hydrology at DRI, lies in the application’s ability to quickly and easily pair satellite imagery with different climate variables.
“We can process field-scale Landsat satellite imagery like we’ve never been able to before,” Huntington said. “For example, we can look at over 30 years of vegetation changes in a certain area and then pair those changes with the same historical record of climate, all within one platform, in a matter of seconds.”
In the paper Climate Engine: Cloud Computing and Visualization of Climate and Remote Sensing Data for Advanced Natural Resource Monitoring and Process Understanding, the authors describe the development, design and potential uses for this tool. The paper highlights various case studies related to drought, wildfire and agriculture, which each provide examples of how Climate Engine can be used to generate on-demand maps and time-series analyses of different conditions and extreme events.
The authors outline the capability of this cutting-edge tool to analyze temperature change in the Arctic, evaluate vegetation stress during a historic drought in the Great Plains, map fire danger and burned acreage in Idaho, monitor groundwater-dependent ecosystems in Nevada, and support famine early-warning efforts in Ethiopia.
Because Climate Engine is free and requires no specialized software to use, Huntington and his colleagues hope that it will be useful to researchers and decision-makers around the world.
“Our work allows decision makers unprecedented access to analyzing big data related to environmental monitoring on their desktops and tablets without needing a supercomputer by using cloud computing resources provided by Google,” said John Abatzoglou, co-principle investigator of Climate Engine and associate professor of geography at the University of Idaho. “The ability to analyze such data in real time will help fill an information void and improve our ability to sustain our environmental resources including water.”
After using the web application to create a map or graph, results can be downloaded or shared in common file formats, saving users hours of time that was once spent downloading and processing large data archives.
“That’s the beauty of Climate Engine,” Huntington said. “Instead of downloading archives to get to the answer, you can just download the answer.”
Climate Engine was originally unveiled at the White House Water Summit in 2016. In the time since the product launched, the web application has been used by more than 8,000 unique visitors across the globe.
Recently, Climate Engine team members Huntington and Dr. Katherine Hegewisch of the University of Idaho presented a talk at the Famine Early Warning System (FEWS) science meeting in Washington D.C., and Hegewisch hosted a workshop for African FEWS field scientists.
Climate Engine will also be on display at the upcoming American Geophysical Union Annual Fall Meeting in New Orleans. The event is the largest and preeminent Earth and space science meeting in the world.
In the future, the Climate Engine team plans to continue adding new datasets such as sea surface temperature and European satellite data. They are also planning to add agency-specific spatial averaging domains, such as agency management boundaries and crop zones, and also hope to continue expanding their education and outreach efforts.
The idea behind Climate Engine, says Huntington, is to make large datasets available to researchers, decision-makers, journalists, farmers, or anyone else who might benefit from the information – and in an easy-to-use, approachable and simple format.
Climate Engine was primarily funded by Google and federal programs of the National Integrated Drought Information System, Famine Early Warning System Network, U.S. Geological Survey’s Landsat Science Team, and Bureau of Land Management’s Nevada State Office.
For more information and use the Climate Engine web application visit – ClimateEngine.org
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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.
The University of Idaho, home of the Vandals, is Idaho’s land-grant, national research university. From its residential campus in Moscow, UI serves the state of Idaho through educational centers in Boise, Coeur d’Alene and Idaho Falls, a research and Extension center in Twin Falls, plus Extension offices in 42 counties. Home to more than 11,000 students statewide, UI is a leader in student-centered learning and excels at interdisciplinary research, service to businesses and communities, and in advancing diversity, citizenship and global outreach. UI competes in the Big Sky Conference and Sun Belt Conference. Learn more at www.uidaho.edu.
Sep 5, 2017 | News releases, Research findings
Above: A 15-meter pan-sharpened Landsat 8 image of the Mount Takahe volcano rising more than 2,000 meters (1.2 miles) above the surrounding West Antarctic ice sheet in Marie Byrd Land, West Antarctica. Credit: Landsat Image Mosaic of Antarctica (LIMA). USGS and NASA, LIMA Viewer, https://lima.gsfc.nasa.gov/. Image Date: March 4, 2015
New findings explain synchronous deglaciation that occurred 17,700 Years Ago
Reno, NV (Sept. 5, 2017) – New findings published today in the Proceedings of the National Academy of Sciences of the United States of America (PNAS) by Desert Research Institute (DRI) Professor Joseph R. McConnell, Ph.D., and colleagues document a 192-year series of volcanic eruptions in Antarctica that coincided with accelerated deglaciation about 17,700 years ago.
“Detailed chemical measurements in Antarctic ice cores show that massive, halogen-rich eruptions from the West Antarctic Mt. Takahe volcano coincided exactly with the onset of the most rapid, widespread climate change in the Southern Hemisphere during the end of the last ice age and the start of increasing global greenhouse gas concentrations,” according to McConnell, who leads DRI’s ultra-trace chemical ice core analytical laboratory.
Climate changes that began ~17,700 years ago included a sudden poleward shift in westerly winds encircling Antarctica with corresponding changes in sea ice extent, ocean circulation, and ventilation of the deep ocean. Evidence of these changes is found in many parts of the Southern Hemisphere and in different paleoclimate archives, but what prompted these changes has remained largely unexplained.
“We know that rapid climate change at this time was primed by changes in solar insolation and the Northern Hemisphere ice sheets,” explained McConnell. “Glacial and interglacial cycles are driven by the sun and Earth orbital parameters that impact solar insolation (intensity of the sun’s rays) as well as by changes in the continental ice sheets and greenhouse gas concentrations.”
“We postulate that these halogen-rich eruptions created a stratospheric ozone hole over Antarctica that, analogous to the modern ozone hole, led to large-scale changes in atmospheric circulation and hydroclimate throughout the Southern Hemisphere,” he added. “Although the climate system already was primed for the switch, we argue that these changes initiated the shift from a largely glacial to a largely interglacial climate state. The probability that this was just a coincidence is negligible.”
Furthermore, the fallout from these eruptions – containing elevated levels of hydrofluoric acid and toxic heavy metals – extended at least 2,800 kilometers from Mt. Takahe and likely reached southern South America.
Monica Arienzo, Ph.D., an assistant research professor of hydrology at DRI, loads an 18,000-year-old sample of the WAIS Divide ice core for continuous chemical analysis using DRI’s ultra-trace ice core analytical system in Reno, Nevada. Credit: DRI Professor Joseph R. McConnell, Ph.D.
How Were These Massive Antarctic Volcanic Eruptions Discovered and Verified?
McConnell’s ice core laboratory enables high-resolution measurements of ice cores extracted from remote regions of the Earth, such as Greenland and Antarctica. One such ice core, known as the West Antarctic Ice Sheet Divide (WAIS Divide) core was drilled to a depth of more than two miles (3,405 meters), and much of it was analyzed in the DRI Ultra-Trace Laboratory for more than 30 different elements and chemical species.
Additional analyses and modeling studies critical to support the authors’ findings were made by collaborating institutions around the U.S. and world.
“These precise, high-resolution records illustrate that the chemical anomaly observed in the WAIS Divide ice core was the result of a series of eruptions of Mt. Takahe located 350 kilometers to the north,” explained Monica Arienzo, Ph.D., an assistant research professor of hydrology at DRI who runs the mass spectrometers that enable measurement of these elements to as low as parts per quadrillion (the equivalent of 1 gram in 1,000,000,000,000,000 grams).
“No other such long-lasting record was found in the 68,000-year WAIS Divide record,” notes Michael Sigl, Ph.D., who first observed the anomaly during chemical analysis of the core. “Imagine the environmental, societal, and economic impacts if a series of modern explosive eruptions persisted for four or five generations in the lower latitudes or in the Northern Hemisphere where most of us live!”
Discovery of this unique event in the WAIS Divide record was not the first indication of a chemical anomaly occurring ~17,700 years ago.
“The anomaly was detected in much more limited measurements of the Byrd ice core in the 1990s,” notes McConnell, “but exactly what it was or what created it wasn’t clear. Most previous Antarctic ice core records have not included many of the elements and chemical species that we study, such as heavy metals and rare earth elements, that characterize the anomaly – so in many ways these other studies were blind to the Mt. Takahe event.”
DRI’s initial findings were confirmed by analysis of replicate samples from WAIS Divide, producing nearly identical results.
“We also found the chemical anomaly in ice from two other Antarctic ice cores including archived samples from the Byrd Core available from the University of Copenhagen and ice from Taylor Glacier in the Antarctic Dry Valleys,” said Nathan Chellman, a graduate student working in McConnell’s laboratory.
Extraction of the WAIS-Divide ice core and analysis in DRI’s laboratory were funded by the U.S. National Science Foundation (NSF).
“The WAIS Divide ice core allows us to identify each of the past 30,000 years of snowfall in individual layers of ice, thus enabling detailed examination of conditions during deglaciation,” said Paul Cutler, NSF Polar Programs’ glaciology program manager. “The value of the WAIS Divide core as a high-resolution climate record is clear in these latest results and is another reward for the eight-year effort to obtain it.”
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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.
Aug 10, 2017 | News releases, Research findings
Monica Arienzo, PhD, assistant research professor of hydrology at DRI, demonstrates part of the black carbon analysis process in the clean room of DRI’s Ice Core Laboratory. Credit DRI.
DRI-led research team publishes longest ice core black carbon record to date
Reno, NV (Aug. 10, 2017): Smoky skies and burnt landscapes are the easily recognizable, local and immediate impacts of large wildfires. Long after these fires are gone, their emissions are cataloged and stored forever in ice covering the Earth’s polar regions.
New research, led by a team at the Desert Research Institute (DRI) in Reno, Nevada, has revealed that Earth’s ancient climate conditions affected large regional scale wildfires.
The new study identifies a link between the concentration of wildfire black carbon (BC) emissions —a type of biomass-burning aerosol particle commonly known as soot—found in Antarctic ice cores and climate conditions in the Southern Hemisphere during the mid-Holocene, about 6,000 years ago.
Led by Monica Arienzo, PhD, an assistant research professor of hydrology at DRI, a team of international researchers used DRI’s unique ultra-trace ice core analytical laboratory to measure BC concentrations in two Antarctic ice cores, ice that contains traces of compounds present in the atmosphere at the time the snow fell. This method allowed researchers to make comparisons to other records, such as lake and marine sediment cores, and develop a high-resolution record of biomass-burning emissions in the Southern Hemisphere from 14 to 2.5 thousand years before present day.
“This is the longest ice core black carbon record published to date,” Arienzo said, “and it tells us a fascinating story about wildfire.”
The new ice core record illustrates that, during the mid-Holocene, decreases in precipitation and soil moisture coupled with increases in temperature and fire season length in regions of South America were mirrored by increased concentrations of BC in Antarctic ice.
“Our analysis gives us a sense of what climate-fire relationships were like before significant human-caused changes to the climate,” explained Joe McConnell, PhD, a study co-author and research professor of hydrology at DRI. “Knowing what climate-fire relationships were like in the past will help scientists make more accurate climate models because they can account for BC contributions from wildfires in addition to those from human sources.”
BC acts as an agent of climate forcing, a process which occurs in the atmosphere when the amount of incoming energy is greater than the amount of outgoing energy, “forcing” the planet to adjust by releasing energy as heat and warming up. This is a natural process, catalyzed by events such as large volcanic eruptions and changes in the sun’s energy output; however, human-caused climate forcing in the form of BC emissions, has increased dramatically since the Industrial Revolution and now is a significant climate forcing agent, second only to carbon dioxide (CO2).
BC also impacts ice sheet albedo, the reflectivity of a surface. Ice and snow have a high albedo because they are very white and reflect much of the sun’s energy. This reflectivity keeps the snow and ice cold and delays melting. Conversely, snow and ice with BC deposits have a lower albedo, causing increased absorption of energy into the snow and ice and more rapid melting.
“Recent precipitation models indicate vast regional changes in rainfall in the Southern Hemisphere in the future,” Arienzo added. “Our findings indicate that such rainfall changes may be accompanied by changes in Southern Hemisphere wildfires. Given that BC emissions from human sources are predicted to increase, our findings are an important factor for climate predictions involving BC impacts.”
The full version of the study—“Holocene black carbon in Antarctica paralleled Southern Hemisphere climate”—is available online at – http://onlinelibrary.wiley.com/doi/10.1002/2017JD026599/full
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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.
Jul 14, 2017 | News releases, Research findings
Researchers monitored mercury levels at Toolik Field Station, northern Alaska, in part, with this meteorological tower (foreground). Credit: Daniel Oberist, DRI.
DRI research team part of international effort to understand global impact
Reno, Nev. (July 14, 2017): Vast amounts of toxic mercury are accumulating in the Arctic tundra, threatening the health and well-being of people, wildlife and waterways, according to a new study published this month by an international team of scientists investigating the source of the pollution.
Led by Prof. Daniel Obrist, chairman of UMass Lowell’s Department of Environmental, Earth and Atmospheric Sciences, an atmospheric chemist and former lead of the Desert Research Institute’s (DRI) Mercury Analytical Lab, the study found that airborne mercury is gathering in the Arctic tundra, where it gets deposited in the soil and ultimately runs off into waters. Scientists have long reported high levels of mercury pollution in the Arctic.
The new research identifies gaseous mercury as its major source and sheds light on how the element gets there.
“Now we understand how such a remote site is so exposed to mercury,” Obrist said. Although the study did not examine the potential impact of global warming, if climate change continues unchecked, it could destabilize these mercury deposits in tundra soils and allow large amounts of the element to find its way into Arctic waters, he added.
Obrist and his colleagues – including students and researchers from DRI – recently completed two years of field research in the tundra, tracking the origin and path of mercury pollution. Working from an observation site in Alaska north of Brooks Range, he and an international group of scientists identified that gaseous mercury in the atmosphere is the source of 70 percent of the pollutant that finds its way into the tundra soil. In contrast, airborne mercury that is deposited on the ground through rain or snow – a more frequent focus of other studies – accounts for just 2 percent of the mercury deposits in the region, Obrist’s team found.
The new research is the most comprehensive investigation on how mercury is deposited in the Arctic. The full results of the study, which was supported by the National Science Foundation, appear in the July 13 edition of the prestigious academic journal Nature.
Mercury is a harmful pollutant, threatening fish, birds and mammals across the globe. The dominant source of mercury pollution in the atmosphere is hundreds of tons of the element that are emitted each year through the burning of coal, mining and other industrial processes across the globe.
This gaseous mercury is lofted to the Arctic, where it is absorbed by plants in a process similar to how they take up carbon dioxide. Then, the mercury is deposited in the soil when the plants shed leaves or die. As a result, the tundra is a significant repository for atmospheric mercury being emitted by industrialized regions of the world.
“This mercury from the tundra soil explains half to two-thirds of the total mercury input into the Arctic Ocean,” Obrist said, adding that scientists had previously estimated mercury runoff from tundra soil supplies 50 to 85 tons of the heavy metal to Arctic waters each year.
Exposure to high levels of mercury over long periods can lead to neurological and cardiovascular problems. The results are being felt by Arctic people and wildlife.
“Mercury has high exposure levels in northern wildlife, such as beluga whales, polar bears, seals, fish, eagles and other birds,” Obrist said. “It also affects human populations, particularly the Inuit, who rely on traditional hunting and fishing.”
Obrist will present the team’s research at the International Conference on Mercury as a Global Pollutant, which will be held Sunday, July 16 through Friday, July 21 in Providence, R.I. The event is the largest scientific conference on mercury pollution, involving nearly 1,000 participants from research institutions, governments and other agencies.
Obrist hopes to continue to investigate whether gaseous mercury is also a dominant source of pollution in other remote lands. Scientists, regulators and policymakers need a better understanding of how the uptake of gaseous mercury in plants and soils is affecting the environment, including the world’s forests, he said.
The research findings underscore the importance of the Minamata Convention on Mercury, the first global treaty that aims to protect human health and the environment from the element’s adverse effects, Obrist said. Signed by the United States and more than 120 other countries, the pact will take effect next month, with the goal of reducing mercury emissions caused by industrialization and other human activities.
Other contributors to the study include scientists from the University of Colorado; Gas Technology Institute in Des Plaines, Ill.; Desert Research Institute in Reno, Nev.; Sorbonne University in Paris, France; and University of Toulouse in Toulouse, France. Additional support for the research was provided by the U.S. Department of Energy, a Marie Sklodowska-Curie grant and funding from the European Research Council and the French National Centre for Scientific Research.
Contributors to this news release included Nancy Cicco, associate director of media relations; and Edwin l. Aguirre, senior science and technology writer/editor, University of Massachusetts Lowell.
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UMass Lowell is a national research university located on a high-energy campus in the heart of a global community. The university offers its more than 17,750 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, vigorous hands-on learning and personal attention from leading faculty and staff, all of which prepare graduates to be ready for work, for life and for all the world offers. http://www.uml.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, please visit www.dri.edu
Jul 14, 2017 | News releases, Research findings
RENO, Nev. (July 14, 2017) – Recently published research led by atmospheric scientists at the Desert Research Institute (DRI) demonstrates a connection between the occurrence of atmospheric river (AR) events and avalanche fatalities in the West.
Published in the May issue of the Journal of Hydrometeorology, the pilot study assessed avalanche reports, weather station data, and a catalog of AR data from a previous study to determine that AR conditions were present for 105 unique avalanches between 1998 and 2014, resulting in 123 fatalities (31 percent of all western avalanche fatalities during this time frame).
Atmospheric Rivers, as described by the National Oceanic and Atmospheric Administration (NOAA), are “relatively long, narrow regions in the atmosphere – like rivers in the sky – that transport most of the water vapor outside of the tropics.”
When ARs make landfall on the West Coast of the US they release water vapor as rain or snow, supplying 30 to 50 percent of annual precipitation in the West and contributing to cool season (November to April) extreme weather events and flooding.
Researchers conclude that the intense precipitation associated with AR events is paralleled by an increase in avalanche fatalities. Coastal regions experience the highest percentage of avalanche fatalities during AR conditions; however, the ratio of avalanche deaths during AR conditions to the total number of AR days is actually higher further inland, in states like Colorado and Utah.
“Although ARs are less frequent in inland locations, they have relatively more important roles in intermountain and continental regions where snowpacks are characteristically weaker and less capable of supporting heavy rain or snowfall,” explained Benjamin Hatchett, a postdoctoral fellow of meteorology at DRI and lead author on the study.
“This means that avalanche forecasters, ski resort employees, backcountry skiers, and emergency managers who have an increased awareness of forecasted AR conditions can potentially reduce exposure to resultant avalanche hazards, particularly if snowpack conditions already indicate weakness,” he added.
The study also reports that shallow snowpacks weakened by persistent cold and dry weather can produce deadly and widespread avalanche cycles when combined with AR conditions. Climate projections indicate that this combination is likely to become more frequent in the mid- to late- 21st century, which could create significant avalanche risk to winter backcountry enthusiasts in the West.
“With increasing numbers of recreational backcountry users and changing mountain snowpack conditions, we might expect the future to be characterized by enhanced exposure to avalanche hazard throughout the western United States,” Hatchett said. “Our results provide motivation to further increase public awareness about avalanche threats during AR events.”
Including integrated vapor transport (IVT) forecasting tools in analyses of avalanche danger, researchers suggest, could potentially allow experts to increase the accuracy of avalanche forecasts when AR conditions are present. These tools can identify structure and movement of ARs when they make landfall, and also model how ARs move inland through gaps in mountainous terrain and cause heavy precipitation further inland.
“Our study provides motivation for additional examinations of avalanche data and meteorological conditions,” Hatchett said. “Our team recommends that following all, but especially fatal, avalanches, as much detailed information should be recorded as possible so that the field can continue to learn about the relationship between atmospheric river events and avalanches.”
The full version of the study – “Avalanche Fatalities during Atmospheric River Events in the Western United States” – is available online at the link below. http://journals.ametsoc.org/doi/full/10.1175/JHM-D-16-0219.1
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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.
