Arctic sea ice regional albedo variability and trends, 1982–1998

Abstract

Whole‐summer and monthly sea ice regional albedo averages for June, July, and August from 1982 to 1998 have been processed from advanced very high resolution radiometer data. Time series for albedo, sea ice concentration, sea ice extent, and surface air temperature have been calculated for the sea ice cover for the Northern Hemisphere as a whole and for six subregions: the Arctic Ocean, the Kara and Barents Seas, the Greenland Sea, the Labrador Sea, Hudson Bay, and the Canadian archipelago. The slope of the summer albedo trend for the Northern Hemisphere is −0.0007 ± 0.0008/year. The largest monthly slope (−0.0016 ± 0.0011/year) is found for June, and the lowest slope (−0.0004 ± 0.0014/year) is found for August. Among the subregions the Greenland Sea has the steepest negative summer trend of −0.0038 ± 0.0012/year during the period, while for the Arctic Ocean the albedo trend is near zero. The calculated trends for the summer sea ice concentration and extent for the Northern Hemisphere are also negative, with a slopes of −0.093 ± 0.069%/year and −42,300 ± 15,200 km2/yr, respectively. In general, the albedo in the central Arctic is between 0.5 and 0.7. The highest albedo values are mainly found in the Arctic Ocean north of Greenland. The lowest albedo (0.2–0.3) occurs in the fringe area of the Arctic Ocean, e.g., on the coasts of Alaska and Siberia. Low albedo values also exist on the east coast of Greenland and in Hudson Bay.