Recent research has combined records of ice measurements from NASA's Ice, Cloud and Land Elevation Satellite, the European Space Agency's CryoSat-2 satellite, airborne surveys and ocean-based sensors, NASA reported Wednesday.
"It's an important achievement and milestone for CryoSat-2," said study co-author Ron Kwok at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
CryoSat-2 and ICESat both measure the amount of ice floating above the ocean's surface, which scientists use to calculate thickness.
This thickness measurement is then combined with ice area to come up with a figure for total volume.
The study's final results show a larger autumn ice volume decrease than predicted, while changes in the winter were smaller than expected, researchers said.
From 2003 to 2008, autumn volumes of ice averaged 2,800 cubic miles, but from 2010 to 2012 the average volume had dropped to 1,800 cubic miles. The average ice volume in the winter from 2003 to 2008 was 3,900 cubic miles, dropping to 3,500 cubic miles between 2010 and 2012.
"It's important to know because changes in volume indicate changes in heat exchange between the ice, ocean and atmosphere," NASA scientist Nathan Kurtz said.