Large-Scale Patterns of Snow Melt on Arctic Sea Ice Mapped from Meteorological Satellite Imagery

摘要

The seasonal progression of snow melt on Arctic pack ice is mapped from satellite shortwave imagery (0.4-1.1 micrometers) for four spring/summer seasons (1977, 1979, 1984 and 1985). This provides the first detailed information on the temporal change of the ice surface albedo in summer and of its year-to-year variability. Average surface albedo of the Arctic Basin for the years investigated falls from between 0.75 and 0.80 in early May to between 0.35 and 0.45 in late July and early August. In the central Arctic, where ice concentration remains high and 0.50 to 0.60. Overall, melt progresses poleward from the Kara and Barents Seas and from the southern Beaufort and Chukchi Seas, with the melt fronts meeting on the American side of the Pole. There are substantial year-to-year differences in timing, duration and extent of the melt interval. Progression of melt in May and June of the earliest melt year (1977) was about 3 weeks ahead of the latest year (1979). By late July, the central Arctic was essentially snow free in 1977 to 1979, but more than 50% snow covered in 1984.