Maximum Thickness and Subsequent Decay of Lake, River and Fast Sea Ice in Canada and Alaska

摘要

Weekly measurements of the thickness of lake, river and fast sea ice made over a period of 10 to 15 years at 66 locations in Canada and Alaska are analyzed, and the portion of the data relating to maximum ice thickness and decay (i.e. the decrease in ice thickness) is examined. Ice thickness curves revealed individual patterns of ice decay, and comparisons between locations disclosed major contrasts in the amount of ice accretion and the times of maximum ice and ice clearance. Although many factors affect the ice decay process, this study investigates in detail the effect of thawing temperatures. Concurrent measurements of the air temperature at each location made it possible to analyze the relationship between accumulated thawing degree-days (ATDD) and ice cover decay. Other factors affecting ice ablation and breakup, such as snow-ice formation, snow cover depth, solar radiation and wind are also discussed. (Author)