IceBridge also will gather data on sea ice in the Weddell and Bellingshausen seas. Because of geographical differences, Antarctic sea ice behaves differently from ice in the Arctic and presents unique challenges. "Sea ice in the Antarctic is a very different physical system," Goddard sea ice researcher Nathan Kurtz said. Ocean currents, precipitation patterns and the shape of land masses are just a few of the differences. Instead of compacting ice against land like in the Arctic basin, currents in the Southern Ocean push much of it farther out to sea. Also, the Antarctic averages more snowfall, which weighs sea ice down and allows ocean water into the bottom layer of the snow on top of the sea ice. The Antarctic has more frequent strong wind events and large temperature swings than the Arctic, which causes layers of ice to form in snow cover. Both of these factors make getting accurate readings of snow on top of sea ice challenging.  

Arctic sea ice extent and volume reached record lows this year, but Antarctic sea ice volume has been holding steady and the extent has been increasing. Predictive models have a hard time pinpointing what Antarctic sea ice might do under a warming global climate. Having more data to work with could make these models more useful. Further observations will give researchers more data on how Antarctic sea ice changes over time. "This is why having observations is really important," Kurtz said. "We want to make sure these models are getting the physics right.  

IceBridge will gather information on many different aspects of land and sea ice using a variety of scientific sensors onboard the DC-8. These instruments include a laser altimeter to measure surface elevation changes, various radar instruments for determining snow depth and ice thickness, a gravimeter that will gather data on the size and shape of water cavities under ice shelves, and a digital camera instrument that takes high-resolution images useful for building maps and digital elevation models of the ice.  

By flying previously surveyed tracks in rapidly changing areas like Pine Island Glacier, IceBridge is building on a legacy of measurements started by NASA's ICESat satellite that will continue with the launch of ICESat-2 in 2016. "This area is changing so rapidly we need to survey every year," Studinger said. In addition, IceBridge will fly along tracks for the European Space Agency's ice-monitoring satellite, CryoSat-2.