UW News

September 10, 2018

UW polar scientists advised NASA on upcoming ICESat-2 satellite

UW News

instrument on dark sky above Earth

An artist’s depiction of the ICESat-2 satellite in orbit. Four solar panels, blue, provide energy while six laser beams send 10,000 pulses per second toward Earth.NASA

NASA plans to launch a new satellite this month that will measure elevation changes on Earth with unprecedented detail. Once in the air, it will track shifts in the height of polar ice, mountain glaciers and even forest cover around the planet.

Two University of Washington polar scientists are advising the ICESat-2 mission scheduled to launch Sept. 15 from California’s Vandenberg Air Force Base. UW researchers provided expertise in two areas of intense interest for long-term tracking: massive glaciers covering Antarctica and Greenland, and sea surface height in the Arctic and other oceans.

“ICESat-2 is designed to answer a simple glaciology question very, very well: It will tell us where, and how fast, the ice sheets are thickening and thinning,” said Benjamin Smith, a glaciologist at the UW’s Applied Physics Laboratory. “When these data start coming in we will immediately get a big-picture map of how Antarctica and Greenland have changed over the past decade.”

If you’re up early Saturday morning, you can watch the launch live during a 40-minute window starting at 5:46 a.m. PDT. Or watch a video of what the deployment will look like.

Read more about ICESat-2 from NASA.

Smith is a member of the science definition team and the lead author of the document that describes the data that ICESat-2 will provide for ice that covers land.

“My specific role is to work out how to turn the raw data that NASA generates — which track the location of individual photons — into the answer we want to give the scientific community, which is how high the ice sheet surface is at a particular point,” Smith said.

The instrument, whose full name is the Ice, Cloud, and Land Elevation Satellite, succeeds the original ICESat-1 satellite that operated from 2003 to 2009. Since then NASA has been running annual IceBridge flights to collect data over a few important parts of Antarctica and Greenland during the gap. The new satellite will provide nonstop, higher-resolution data for the Earth sciences community starting this October, one month after it launches.

“For me, the most exciting aspect of ICESat-2 is its extremely fine resolution,” said Jamie Morison, a polar oceanographer and former leader of the North Pole Environmental Observatory. The new satellite uses six laser beams to get readings every 2-3 feet, each one focused over a 30-foot patch of the surface. For comparison, Morison said, today’s instruments measure surface elevation by averaging over many hundreds of feet to miles between each data point. The new instrument’s orbit is designed to collect more data over the poles, and it can detect very small elevation changes over long timescales.

Morison is a physical oceanographer on the science definition team, and lead author the document that describes ICESat-2 data for the open oceans.

“For the oceans, ICESat-2 will yield fine-scale measurements that are important to coastal oceanography, revealing smaller features in the open ocean and even down to the characteristics of larger surface waves,” Morison said. “ICESat-2 will also help measure sea-level change, particularly at high latitudes where the most established radar altimeters don’t go, and it will give us higher-resolution measurements of the sea surface slopes that drive changing ocean circulation.”

The two UW researchers were members of a 12-person science team that consulted on the project over the years leading up to the launch. They also are among the hundreds of scientists who anticipate using the data in their research.

“ICESat-2 observations will make it possible to study glaciers that are too remote for aircraft to reach, and it will make it possible to detect small changes over large areas, which were difficult to see clearly with older data,” Smith said. “There are a lot of places in Antarctica where we assume that not much is happening, but we don’t have great evidence one way or another. My guess is that when we look carefully, there will be a lot to see.”


For more information, contact Smith at besmith@uw.edu or 206-616-9176 and Morison at jhm2@uw.edu or 206-543-1394. More ICESat-2 multimedia is here.

They will be available in Seattle until Thursday, Sept. 13, when they will travel to California for Saturday’s anticipated launch.