Large-Scale Patterns and Variability of Snowmelt and Parameterized Surface Albedo in the Arctic Basin

Abstract

Visible-band satellite imagery is used to manually map surface brightness changes over sea ice throughout the Arctic Basin from May to mid-August over a 10-yr period. These brightness changes are primarily due to snowmelt atop the ice cover. Using image processor techniques, parameterized albedos are estimated for each brightness class. Snowmelt begins in May in the marginal seas, progressing northward with time, finally commencing near the pole in late June. large year-to-year differences are found in the timing of melt, exceeding one month in some regions. Parameterized albedo for most regions of the pack ice exceed 0.70 during May, declines rapidly during June, and reaches a seasonal low of between 0.40 and 0.50 by late July. For August, regional albedos, which also include areas of open water beyond the southern pack ice limit, are up to 0.16 lower than the corresponding values for pack ice areas only.