US: NASA scientists begun second year of airborne surveys over Antarctica. The mission monitors the region’s changing sea ice, ice sheets and glaciers. Researchers made flights from Punta Arenas, Chile, on NASA’s DC-8, a 157-foot airborne laboratory equipped with a suite of seven instruments. The focus is on re-surveying areas that are undergoing rapid change and embarking on new lines of investigation.
Michael Studinger, IceBridge project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said, “We are mapping uncharted regions that will allow us to better assess future behaviour of the Antarctic ice sheets and sea ice.” IceBridge science flights are scheduled to continue through mid-November.
Instruments for the 2010 Antarctic campaign are the same as those flown in 2009. A laser instrument will map and identify surface changes. Radar instruments will penetrate the snow and ice to see below the surface, providing a profile of ice characteristics and also the shape of the bedrock supporting it. A gravity instrument will measure the shape of seawater-filled cavities at the edge of some major fast-moving glaciers.
Using these tools, researchers will survey targets of on-going and potential rapid change, including the West Antarctic Ice Sheet, which is the area that has the greatest potential to rapidly increase sea level. Another concern is that the ice sheet is below sea level, adding to its instability.
Pine Island Glacier, the largest ice stream in West Antarctica with significant potential contribution to sea level rise, has long been a primary target for sustained observations. Satellite data, most recently from NASA’s Ice, Cloud and land Elevation Satellite (ICESat) have shown dramatic thinning there of up to 10 meters per year in places.
Flights are being planned to be coordinated with existing space and ground-based missions, such as the European Space Agency’s ice-observing Cryosat-2 satellite and European ship-based research. Overlapping measurements help researchers calibrate instruments and boost confidence in the resulting observations.
“A concerted effort like this will allow us to produce long time series of data spanning from past satellite missions to current and future missions,” Studinger said. “This is only possible through international collaboration.”