Field Notes From a DRI Research Team in Greenland: A Story Map

Field Notes From a DRI Research Team in Greenland: A Story Map

Field Notes From a DRI Research Team in Greenland: A Story Map

In May 2022, a team led by scientists from DRI in Reno, Nevada departed for Greenland, where they were joined by ice drilling, Arctic logistics, and mountaineering experts. Together, the team plans to collect a 440 meter-long ice core that will represent 4,000 years of Earth and human history.  

For much of their time on the Greenland ice sheet, the team will not have access to the internet or phone service — but they are able to send short text messages back to DRI from a Garmin inReach two-way satellite communicator. You can follow along with their journey on our Story Map, “The Return to Tunu.” 

Study shows a recent reversal in the response of western Greenland’s ice caps to climate change

Study shows a recent reversal in the response of western Greenland’s ice caps to climate change

Study Shows A Recent Reversal in the Response of Western Greenland’s Ice Caps to Climate Change

Sept 9, 2021

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)

Ice capped and snow-covered mountains of coastal west Greenland. (Apr. 2015)

Credit: Matthew Osman © Woods Hole Oceanographic Institution

Thumbnail image of nature geoscience paper

The full text of the study, “Abrupt Common Era hydroclimate shifts drive west Greenland ice cap change,” is available from Nature Geoscience: 

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.

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. 

University of Arizona postdoctoral research associate Matthew Osman and U.S. Ice Drilling Program specialist Mike Waszkiewicz move an ice core barrel into place in West Greenland, as part of their work to study ice caps’ response to climate change.

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. 


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

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

Meet Nathan Chellman, Ph.D.

Meet Nathan Chellman, Ph.D.

Meet Nathan Chellman, Ph.D.

MAR. 25, 2021

Ice Cores
Climate Change

Meet DRI scientist Nathan Chellman and learn about his work in the Ice Core Laboratory in this interview with DRI’s Behind the Science Blog.

Nathan Chellman, Ph.D., is a postdoctoral fellow with the Division of Hydrologic Sciences at the Desert Research Institute (DRI) in Reno, Nev. He specializes in the collection, processing and analysis of ice cores — cylindrical samples of ice drilled from glaciers and ice sheets around the world. Nathan grew up in Reno, and holds a B.Sc. in Geology/Biology from Brown University, and M.S. and Ph.D. degrees in Hydrology from the University of Nevada, Reno. He first worked at DRI as a high school intern in 2008, then later returned to DRI during and after college to work with Joe McConnell in the Ice Core Lab. He received his helicopter private pilot license in 2014 and volunteered as an EMT while he was an undergraduate. In his free time, Nathan enjoys running, skiing, and backpacking in the Sierras and central Nevada.

DRI scientists Yuan Luo (left) and Markus Berli (right) inside of DRI's SEPHAS Lysimeter facility in Boulder City, Nev.

Nathan Chellman, Ph.D., is a postdoctoral fellow with the Division of Hydrologic Sciences at the Desert Research Institute in Reno.

DRI: What do you do here at DRI?

Chellman: I work in the Ice Core Lab, where we do analyses and measurements on snow and ice from polar and alpine regions to learn about how the environment has changed over the past several centuries and millennia. I also do some work with tree rings and sediment cores from areas a little closer to home, like the Rocky Mountains, primarily looking at pollution and climate reconstructions.

DRI: What does an ice core look like, and how do you collect one?

Chellman: An ice core is a long, narrow cylinder of ice. To recover an ice core from an ice sheet or a glacier we use an ice core drill, which is a hollow tube with sharp cutters at one end and a big motor at the top. The motor spins the hollow tube, the cutters cut the ice away, and the ice core then ends up in the center of the hollow tube. You send the ice core drill down through the ice about 1 meter (3 feet) at a time, bring up the entire drill with an ice core inside, push the ice core out of the hollow drill section, send the drill back down the borehole, and then repeat that until you’re the whole way through the ice feature. For polar ice cores, we sometimes drill down hundreds of meters. So, we end up with hundreds or thousands of those meter-long sections back-to-back that represent a whole profile through the ice.

Above, left: Researchers process an ice core sample collected from a glacier in Greenland. Above, right: Closeup of an ice core drill.

Credit: Michaeol Sigl (left photo); Nathan Chellman/DRI (right photo).

DRI: What can you learn from all of these samples of ice? Can you tell us about one of your projects?

Chellman: One of my favorite projects right now is a study on some really old ice patches in Wyoming. These ice patches are about the size of a football field or smaller, so they are too small to be glaciers. They look just like little remnant snow patches that you might see in the Sierra Nevada if you go out hiking in the late summer. However, they’re not snowdrifts, they’re actual ice – and some of these ice patches are turning out to be thousands and thousands of years old.

I was invited to join the project by a group of archaeologists and climate scientists who were interested in looking at how old the ice patches were, and studying the organic debris inside of them and the artifacts that were melting out around the edges. They didn’t know what to do with the ice itself, but since we specialize in measuring ice chemistry, I volunteered to go to their field site when they were drilling through a shallow ice patch and bring some ice back to DRI. Those samples ended up being a very nice record of ice chemistry. The ice patch turned out to be 10,000 years old at the bottom, with about 30 organic layers cutting through the ice.

Normally in an ice core project, if you have dirt and organic layers in your ice core you’ve done something terribly wrong. In this case, the dirt was the key to unlocking how old the ice patch was, since the age of the organic material can be accurately dated. It turned out that the chemistry of the ice was really interesting as well, and preserved some climate information going back over ten thousand years. You can see distinct warm and cold periods that paralleled lake sediment records from nearby, and also some anthropological records of population. So, that suggested that people living in the area were affected by the general climate conditions as indicated by the ice patch chemistry.

Above, left: Nathan Chellman carries ice coring equipment to an alpine ice patch, where he and his colleagues are using ice core records from an isolated ice patch to learn about ancient climate in the region. Above, right: Chellman holds an ice core sample collected from an alpine ice patch.

Credit: Monica Arienzo/DRI.

DRI: Have you ever been part of a polar drilling operation?

Chellman: Yes, in 2013 I was in northeastern Greenland. That year we recovered a 212-meter ice core, which went back about 1,700 years. It took about two weeks working normal 8- or 10-hour days – but as you drill deeper and deeper into the ice, it takes longer and longer for the drill to go up and down the borehole. On the first day you can go about 20 meters in a day, and the next day you can go a little less, and by the end you’re only drilling 6 to 10 meters per day because it takes so long for the drill to go up and down the hole.

The first day was terrifying. The plane landed out in the middle of the ice sheet, hundreds of miles from any other camps or bases. The pilot dropped us and our gear out in the snow, and then took off and left. Help was a few days away at best, so we had to just get working and get camp set up before everything blew away, because it’s always windy there. There were no buildings, no infrastructure, just us and our camping gear. We had personal sleeping tents (we each used two sleeping bags!), a kitchen tent, and a science tent, as well as plenty of food, Coleman stoves for cooking, and the ice core drill.

DRI: What were the working conditions like in Greenland?

Chellman: The strangest part about working in Greenland during the summer is that it’s never night. The sun never completely goes down, even at night. The sun goes low on the horizon and it gets colder, but it’s never actually dark. It’s a little disorienting at first. You have to sleep with eye covers or pull your hat down over your eyes so you can pretend like you’re in a little bit of darkness.

It was also really cold. Between -25 and -35C (-13 to -31F) at night, and anywhere between -5 and -15C (23F to 5F) during the day. When it’s that cold, it’s really interesting because you have to consider that everything is going to be frozen. Your toothpaste is going to be frozen, if you leave your water in a mug it’s going to be frozen. It requires some adaptations from a lifestyle perspective to make sure what you need isn’t going to be a total block of ice.

Yuan Luo near a lysimeter tank at DRI's SEPHAS Lysimeter facility in boulder city, nevada

In 2013, Chellman and his colleagues traveled to northeastern Greenland to collect a 212-meter ice core that went back 1,700 years. Their field camp is pictured here.

Credit: Nathan Chellman/DRI.

DRI: Do you have any plans to return?

Chellman: We were supposed to go back last year to that same place in Greenland and get an ice core that was twice as long, but that was postponed. We’re rescheduling for this spring, but everything is still very much up in the air. If we go, we’ll be gathering data for a study that is trying to understand pollution from ancient societies. For example, we will be looking to see if we can detect Bronze Age pollution from 2,000-3,000 years ago in the ice. The pollution would have been caused by mining and smelting of metals.

DRI: It sounds like you have a very exciting job. What do you like best about what you do?

Chellman: One of my favorite things is actually being in the lab and making the measurements, and taking all the time to make sure everything is running right, and that the analytical system and all the instruments are making high-quality measurements. When you’re analyzing ice cores, you have to be consistent day to day and week to week, since sometimes it can take a month or two to analyze all the samples from an ice core. But it’s really fun to get in the groove in the lab, run long days, and generate really consistent, nice datasets. There’s a lot of troubleshooting involved, but once the system is running smoothly, it’s really amazing to be able to generate unique, one-of-a-kind data that can be trusted to inform really big picture questions.

Additional Information:

For more information on Nathan Chellman and his research, please visit:

For more information on the DRI Ice Core Laboratory, please visit:


Researchers Markus Berli and Yuan Luo near a sign for the Desert Research Institute

DRI scientist Nathan Chellman.

Credit: Nathan Chellman/DRI.