NASA Heads To Greenland Just In Time For The Latest Heatwave

Russell Glacier in western Greenland is melting from the Greenland Ice Sheet and flowing out to sea where it will contribute to sea level rise.

Credit: Laura Faye Tenenbaum

NASA oceanographer and climate scientist Josh Willis and his team are set to arrive in Greenland on August 9 just one week after a scorching heatwave. They’ll collect data on ocean temperature and salinity, which will help them determine how much the ice melts when the water warms, what the current melt rate is, and how much that melt rate is increasing.

Warm ocean water around Greenland is bad news for the ice sheet because as ocean water around the coastline becomes even warmer, Greenland’s glaciers melt even faster than they already are. A faster melting Greenland would be devastating, not only for the Greenland Ice Sheet, but for coastlines everywhere. The melted ice flows into the ocean and causes sea level rise worldwide. Sea level rise, which has accelerated over the last 30 years, is one of the most important indicators of climate change and one of its most troubling consequences. The repercussion of oceans rising up and swallowing land disrupts the economy for everyone, even those who don’t live on the coast.

This year will be the fourth season that NASA’s Oceans Melting Greenland, or OMG for short, will survey the ocean waters around Greenland’s coastline to monitor how quickly the glaciers are melting.

Every spring since 2016, the OMG team flies a radar instrument over almost every marine-terminating glacier in Greenland to precisely measure each glacier individually and determine how quickly each one is thinning, using the Airborne Glacier and Land Ice Surface Topography Interferometer (GLISTIN-A), a radar instrument attached to the bottom of a modified NASA G-III aircraft. Data collected over the five-year-mission can be used to determine how fast the glaciers are melting.

Then the team returns to Greenland in the late summer, early fall to measure ocean temperature and salinity from the sea surface to the sea floor around Greenland via about 250 Aircraft eXpendable Conductivity Temperature Depth (AXCTD) probes. “In most of these places,” Willis said, “there hadn’t been any temperature or salinity data collected here before OMG.”

“There’s evidence of the ice sheet disappearing all around the edges,” Willis said. “I can see it clearly from our plane. I see big scars in the rock where glaciers used to extend a mile or two downstream, but recently retreated and left a canyon behind.”

A glacier on Greenland's northwest coastline as seen from NASA's G-III modified aircraft. Ice from the Greenland Ice Sheet flows down the glacier and melts into the ocean.

Credit: Laura Faye Tenenbaum

OMG was designed to be a five-year mission, which is useful because the North Atlantic Ocean has a natural 5-20 year cycle of warm phase to cold phase to warm phase again. Willis’ team already learned that the oceans are important for controlling the pace of ice loss around Greenland. But he hopes that this season, they’ll be able to understand what happens during the entire natural cycle of warming and cooling. They’ll be able to use what they learn about this natural cycle to predict the impact of long term warming due to human induced climate change, using the natural fluctuations as a benchmark in order to calibrate how global warming will impact the amount of ice loss around Greenland.

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