A paper published last month in the journal Climatic Change reveals "the magnitude and even direction of recent Antarctic climate change is still debated." The paper states the Antarctic Peninsula is warming, but that "in continental Antarctica [where by far the most ice is located] a cooling trend was recently detected." Also confounding, the surface temperature of permafrost areas is warming, "although the air temperature was almost stable."
A permafrost warming in a cooling Antarctica?
Mauro Guglielmin and Nicoletta Cannone
Abstract: The magnitude and even direction of recent Antarctic climate change is still debated because the paucity of long and complete instrumental data records. While along Antarctic Peninsula a strong warming coupled with large retreat of glaciers occurred, in continental Antarctica a cooling was recently detected. Here, the first existing permafrost data set longer than 10 years recorded in continental Antarctica is presented. Since 1997 summer ground surface temperature showed a strong warming trend (0.31°C per year) although the air temperature was almost stable. The summer ground surface temperature increase seemed to be influenced mainly by the increase of the total summer radiation as confirmed also by the increase of the summer thawing degree days. In the same period the active layer exhibited a thickening trend (1 cm per year) comparable with the thickening rates observed in several Arctic locations where air warming occurred. At all the investigated depths permafrost exhibited an increase of mean annual temperature of approximately 0.1°C per year. The dichotomy between active layer thickness and air temperature trends can produce large unexpected and unmodelled impacts on ecosystems and CO2.