March 24, 2019 | 47° F

Rutgers scientists study climate change in Greenland

Photo by Courtesy of Åsa Rennermalm |

Greenland’s melting ice sheets are forming meltwater lakes on the surface.

Åsa Rennermalm brought some of her most valuable, high-tech research equipment to Greenland for her master’s thesis, only to have it break when she got there.

“This was a place on northeast Greenland where you have 20 people and the nearest town is in Iceland, which is a six-hour flight away. … It’s just not a place where you can send it for repairs,” said Rennermalm, an assistant professor of Geology at Rutgers.

She said she was fortunate enough to have an electrical engineer with her, and after three weeks of working on the instrument they finally got their data.

Rennermalm has been to Greenland for a total of nine summers, and since her arrival to Rutgers in 2008, she has gone there every year with funding from the National Science Foundation and NASA to research how the changing climate affects the movement of ice and water on the cold, remote island of 60,000 people.

Rennermalm said many people have misconceptions about the work of modern geographers.

“They have this ancient understanding that we just sit here and study maps,” she said. “Really, it’s about the 21st century challenge — how are we as humans going to live on this planet?”

Rennermalm’s work centers on the physical, and therefore human implications of climate change. In Greenland, she measures runoff from ice sheets into streams and rivers, she said.

Thomas Mote, head of the Department of Geography at the University of Georgia, said he collaborated with Rennermalm to determine the change in mass of the Greenland ice sheet, and how that change could affect the surrounding ocean.

“We know there’s a warmer climate over Greenland, we know that we have increased melt, the question is what happens to that meltwater?” he said.

He said their research would help to make better predictions on the effects of climate change over time.

If scientists could understand how climate change is currently affecting the environment, he said they could reduce the error bars on models of the future.

Rennermalm said the researchers used input and output measurements to find out how much of the meltwater ended up in the ocean. She and her team are discovering the picture is far more complicated that previously thought.

“We found the ice sheet has these meltwater lakes forming on the surface where it can be stored,” she said.

Snow layers can also contain a lot of meltwater, she said, creating a buffering effect between when the ice melts and when it actually leaves the ice sheet to head toward the ocean.

They have found out a lot using data taken from weather stations, satellites and their own work.

Rennermalm said she has learned her lesson about keeping robust instruments. To measure the changing meltwater patterns, she uses the same tool the U.S. Geological Survey has used for 100 years.

The tool has a propeller at the end, and it records the number of times the propeller spins, she said. From there, they can determine water speed and flow.

Meanwhile, the team lives in tents on the side of the ice sheet. Typically they stay in this remote location, living on canned food and talking through a special Satellite phone for three- to five-day stretches.

They travel to the nearest town an hour and a half away to shower and eat muskox and reindeer at the local cantina, she said. Then they are back to work.

“When you’re out on the field, personnel is very important,” she said. “You definitely need to find people you can work well with because you’ll be spending a lot of time with them.”

John Mioduszewski, a graduate student in the Department of Geography, said he and Rennermalm often worked together during their trip.

He would cook and help with the set up and measurement of instruments, he said. Often a two-person job, one of them would place the instrument in the river while the other would read the data and record it.

He said he also learned to improvise during disasters in the field.

“While we were on the ice sheet, my very expensive GPS slipped from my hand. … And things that you drop on the ice sheet have a tendency to find their way into the water,” he said. “It immediately went 2 meters per second, as we had just measured, into a melt lake.”

He decided the information it contained was just too important, so he took off his boots, rolled up his sleeves, and walked straight into the river to get the device.

“Somehow it still worked,” he said.

Yet the most work happens back in the United States. Samiah Moustafa, a graduate student in the Department of Geography, collaborated with Rennermalm to analyze the hydrology, or the movement of water, in Greenland.

From the data, she concluded 50 percent of the original meltwater is not finding its way into normal runoff.

“This tells us that the ice sheet is extremely complex,” she said.

She also is working on a side project to determine surface reflectivity of the ice sheet, also known as albedo. The findings may have implications for how meltwater forms and runs off.

“It requires us to use a very diverse skill set,” she said. “Logistically some of this data would be very difficult to get from our work in the field there, so we have to use all sorts of alternative resources.”

She said fieldwork was interesting because she saw the landscaping change every day with the climate.

They could go back to somewhere a day later and find the topography completely altered, she said.

At Rutgers, Rennermalm said she teaches several courses in geography and will teach a Byrne Seminar next semester on the Arctic.

She said she enjoyed doing her research at Rutgers. A native of Stockholm, Sweden, she lived in many places, from Copenhagen to Los Angeles, while she got her education.

Ironically, the only place she did not like was her first undergraduate college, located in northern Sweden.

“It was too cold,” she said. “It snowed from October to May.”

By Erin Petenko

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