Arctic climate characteristics and recent trends based on the AVHRR Polar Pathfinder data set

The newly available Advanced Very High Resolution (AVHRR) Polar Pathfinder (APP) data set of 18 years from 1982 to 1999, subsampled to a 25 km scale, was used to retrieve cloud amount, optical depth, particle size, temperature, particle phase, surface temperature, surface albedo and radiation fluxes over the Arctic Ocean and surrounding land areas. An analysis of the seasonal and interannual variability in those parameters is presented. Results show that the Arctic climate has indeed undergone changes in surface temperature, surface broadband albedo and cloud amount at the 95% confidence level for summertime (July), implying an Arctic warming, but no significant trends were found for the wintertime (January). The significant turning point of the Arctic climate occurred the late 1980s and early 1990s.