ABSTRACT
Satellite monitoring of sea ice cover in the Arctic is essential for understanding the climate and ecological processes. Results of numerical investigations show that Arctic sea ice affects the climate by regulating the exchange of heat, moisture and momentum between the ocean and atmosphere and is a potential early indicator of global climate change. Regional yearly variations in the seasonal distribution and abundance of sea ice have been shown to have significant effects on Arctic marine ecosystems and on the reproduction and survival of Arctic marine mammals and birds. For example, a decrease in sea ice cover may stimulate an initial increase in biological productivity. However, it is likely that polar bear, seal and other populations will decline wherever the quality and availability of breeding habitat are reduced (Stirling, 1980; Smith et al., 1991; Stirling et al., 1993; Stirling, 1996). A number of studies have suggested that changes in the global average air temperature might be detectable by observing changes in the extents of the Arctic sea ice cover. Minimum sea ice extent and concentration during the summer provide indirect information required for evaluation of heat and humidity fluxes among the ocean, atmosphere and perennial ice pack (Parkinson, 1991A; Gloersen and Campbell, 1991). One sensitive region in the context of global change is the Barents and Kara Seas and adjacent parts of the Arctic Ocean. Documenting variations in the annual minimum ice extent and concentration in this region is important for understanding historical periodicity, and for investigating long-term trends. However, long-term trends derived from ice maps are fixed estimates without variance.
