The AVHRR Polar Pathfinder Extended (APP-x) climate data record provides cloud properties, surface temperature and albedo, sea ice thickness, and radiative fluxes over the Arctic and Antarctic from 1982 through the present. APP-x was recently used in two studies of absorbed solar radiation at the surface. One study compares changes in sea ice extent in the Arctic and Antarctic and examines their effects on the shortwave radiation budget. It was found that increasing shortwave absorption over the Arctic Ocean is not balanced by trends in the Antarctic. The second study compares the ice-albedo and snow-albedo feedbacks in the Arctic. The positive trend of solar absorption over the Arctic Ocean is more than double that over Arctic land, and the magnitude of the ice-albedo feedback is four times that of the snow-albedo feedback in summer. Therefore, decreasing sea ice cover, not changes in terrestrial snow cover, has been the dominant radiative feedback mechanism over the last few decades.
Referenced during talk: Role of Land-Surface Changes in Arctic Summer Warming