Gains in Antarctic Sea Ice Cover Triggered by Wind Shifts, Study Says

Scientists say they have the first direct evidence that changes in Antarctic sea ice drift caused by changing winds have produced an increase in Antarctic sea ice cover over the last two decades even as historic declines have been observed in the Arctic. Using more than 5 million measurements of daily sea ice movement collected over 19 years, researchers from NASA and the British Antarctic Survey detected long-term changes in sea ice drift, a phenomenon that has caused overall increases in sea ice cover. While sea ice around Antarctica is constantly being blown away from the continent by northerly winds, the rate of ice movement in some areas has doubled since 1992, causing total sea ice, which reflects heat from the sun, to expand out from Antarctica, according to their findings, which were published in Nature Geoscience. “The Antarctic sea ice cover interacts with the global climate system very differently than that of the Arctic, and these results highlight the sensitivity of the Antarctic ice coverage to changes in the strength of the winds around the continent,” said Ron Kwok of NASA’s Jet Propulsion Laboratory.