Chapter 14 - Arctic sea ice variability and trends in the last four decades: role of ocean-atmospheric forcing

Abstract

Accelerated decline is recorded in the Arctic sea ice extent and sea ice concentration over the past four decades. The ocean–atmosphere coupled mechanism plays an important role in global climate change. Sea ice variability and trends were computed using satellite and model reanalysis measurements for the total Arctic and each of their nine regions: (1) Seas of Okhotsk and Japan, (2) the Bering Sea, (3) the Hudson Bay, (4) the Baffin Bay/Labrador Sea, (5) the Gulf of St. Lawrence, (6) the Greenland Sea, (7) the Kara and Barents Seas, (8) the Arctic Ocean, and (9) the Canadian Archipelago. Overall Arctic sea ice declined in all seasons and on a yearly average basis, although the highest and lowest negative trends were recorded in summer and winter/spring, respectively. The study reveals that regionally mainly four sectors—the Arctic Ocean, Kara and Barents Seas, the Greenland Sea, and the Baffin Bay region—are majorly responsible for the negative sea ice extent trend for the total Arctic as a whole. The study demonstrated the interannual and seasonal variabilities of Arctic sea ice and interactions among the atmosphere, ice, and ocean.