Why is NASA in Greenland?
Greenland’s melting ice affects the whole world. Greenland’s ice sheet contains enough water to raise sea levels by 7.4 meters (25 feet) worldwide.
Warmer air is melting Greenland’s ice. But so are warmer oceans.
NASA’s Oceans Melting Greenland (OMG) mission is trying to figure out how much of Greenland’s ice melt is caused by warming oceans.
Why is the climate warming?
Humans are changing the climate by burning fossil fuels for energy. These add greenhouse gases to the atmosphere, which trap extra heat from the sun and warm the air and oceans.
But the oceans get most of the extra heat. In fact, more than 90% of the heat trapped by greenhouse gases warms the oceans, not the air.
OMG started its 5-year mission in 2016. Each year, OMG does two surveys, all the way around Greenland:
In summer, there is less sea ice. With more open water, this is the best time to drop ocean probes next to the Greenland coast.
Each year, OMG drops about 250 ocean probes to measure the temperature and saltiness of the water around Greenland.
To drop a probe, the aircraft flies low (between 500–5000 feet) in order to make sure that no people, equipment, or wildlife are near the drop zone.
Do the probes bother ocean animals? No, the probes don’t emit any sounds and operators always make sure the water is clear before dropping them.
Spring is the best time to fly the radar over Greenland. It’s just before the snow melts, and the dry snow gives a better return for the radar.
So every spring, the Glacier and Ice Surface Topography Interferometer (GLISTIN-A) radar—also known as UAVSAR’s Ka-band radar—is deployed to Greenland on NASA’s G-III plane. It flies 80 lines over Greenland’s more than 200 glaciers.
The radar measures glacier heights and also finds the edges of the glaciers. This allows OMG scientists to see how the thickness of the glaciers is changing over the years.
Data collected by OMG using the probes, the radar and other means are all freely available to anyone by visiting the Browse Data page on this portal. These data have already been used in many important discoveries by scientists and are also of wide interest to people in Greenland and beyond. See the following article to learn more.
Josh Willis, OMG’s principal investigator (PI), takes you along for the mission and drops some ocean probes. (Transcript)