October 15, 2009
UW oceanographer is a lead scientist in largest airborne survey of polar ice
By Sandra Hines
News & Information
During the next six years Operation Ice Bridge will use aircraft to conduct what NASA says is the largest airborne survey ever made of ice at the Earth’s polar regions.
Flights over Antarctica, with UW oceanographer Seelye Martin as chief scientist, start Oct. 15. Martin leaves Friday to begin his journey to Punta Arenas at the tip of Chile, from where a NASA DC-8 research aircraft will make flights over the Antarctic Peninsula and West Antarctica through mid-November. The Antarctic work follows the first Operation Ice Bridge flights last spring over Greenland and the Arctic Ocean. The plan is to map key areas in each polar region once a year.
Operation Ice Bridge will help fill a gap in ice-thickness information that’s been collected by a satellite called ICESat that will probably reach the end of its operational life later this year. A replacement satellite won’t be ready until 2015-2016.
“We would just be blind for six years without these aircraft flights,” Martin says. On board the aircraft, he says, will be instruments such as ice-penetrating radar that will provide three-dimensional views of ice sheets, outlet glaciers and ice shelves. Researchers also will take ice thickness profiles in the Weddell and Amundsen Seas.
“The excitement for me in helping to plan and run this campaign is to participate in the design of experiments to replace the observations made by the aging NASA ICESat satellite, and to focus airborne observations on the rapidly changing regions of the Greenland and Antarctic ice sheets,” Martin wrote in the opening blog for the project, part of the overall Web site at http://www.espo.nasa.gov/oib/.
Changes in Greenland and Antarctic ice are of interest because melting contributes to sea level rise around the world.
Researchers have calculated that since the pioneering NASA aircraft studies in the 1990s, the outflow of fresh water and ice from Greenland has increased 7 percent a year. Scientists want to determine the equivalent rate for Antarctica. Martin says it’s important to know because Antarctica’s ice contribution to sea level rise could potentially be much greater than that of Greenland.
The current ICESat gives continent-wide measurements that are impractical to gather with aircraft. On the other hand, the DC-8 will carry instruments that allow the scientists to examine things the satellite does not. Aircraft ice-penetrating radar, for example, can measure the ice-sheet thickness and gravity measurements can infer the depth of seawater beneath the ice shelves. All this information is critical for numerical modeling of the ice behavior and mass changes, Martin says.
The flights this fall will involve 50 people from four NASA centers and five U.S. universities. The work is being done in cooperation with Chilean and British scientists.
