Large Scale Characteristics and Variability of the Global Sea Ice Cover

摘要: More than two decades of satellite passive microwave data are used to study and evaluate the large scale characteristics changing state sea ice cover in both Northern Southern Hemispheres. Satellite provide day/night almost continuous observation global thereby enabling quantitative variability studies at various time scales. Despite coarse sensor resolution, spatial detail is provided through use concentrations which derived using an algorithm that determines fraction open water within each footprint. Large seasonal fluctuations extent apparent with those Hemisphere having larger amplitudes but less symmetrical distribution Hemisphere. The interannual has been evaluated globally as well regionally Hemisphere, yearly anomaly maps show a predominance positive values 1980s negative 1990s. Regression analysis area on decline rate -2.0 +/- 0.5% -3.1 0.3% per decade, respectively, there regions like Bering Sea trends. What intriguing, however, perennial declining much faster for entire hemisphere, i.e., 6.7 2.4% 8.3 2.4 % decade area, respectively. consists mainly thick multiyear floes, its persistent would mean reduction average thickness change overall Arctic cover. Furthermore, patterns coherent surface temperatures from 19 years thermal infrared AVHRR data. latter also shows consolidated regions, temperature during summer minima increasing about 0.9 0.6 K decade.