Arctic Sea Ice Thinning Up to Twice as Much as Previously Estimated

The Cryosphere, June 4

Between 2002 and 2018, sea ice in the Arctic thinned 60 percent more than previously estimated. In particular, the coastal area of the Chukchi Seas, just above Alaska and the Kamchatka Peninsula, thinned over twice as much as past calculations have shown. Sea ice extent, or area can easily be measured using satellites, but sea ice thickness is much more difficult because the snow on top of the sea ice is hard to measure, and therefore estimated in comparison to the ice below. Snow cover estimates used previously were however based on data collected between 1954 and 1991, when the Arctic Ocean still had extensive thick multiyear ice, with deeper snow cover. This study therefore updated estimates of snow cover to improve more recent measurements of sea ice thickness, and found it was much thinner than earlier reported; since the previous estimates were erroneously counting snow cover as a portion of sea ice. Authors emphasize that the decline of sea ice thickness has numerous and global implications on shipping, fisheries, and wildlife.

https://tc.copernicus.org/articles/15/2429/2021/