Amplification of changing surface temperature extremes over land in a warmer climate

Anthropogenic climate change can alter surface temperature extremes differently from changes in the mean. This differential warming of extremes from the mean varies significantly across season and region. In the tropics, hot extremes are projected to warm more than the mean and this amplification is most pronounced during summertime. In the high latitudes, cold extremes are projected to warm more than the mean and this amplification is most pronounced during wintertime. Furthermore, there are regional hotspots of warming extremes. Hotspots in the tropics include Southeast Asia, Amazonia, Sahel, and Southern Africa and in the high latitudes include Eastern Canada and Europe. In this talk, I will discuss the physical mechanisms that contribute to these seasonal and spatial patterns of amplified warming of hot and cold extremes. We find that the key ingredient for amplified hot-day warming in the tropics is decreasing soil moisture and amplified cold-day warming in the high latitudes is the amplification of mean warming in the Arctic. These features, while robust in projections of future climate change, have not yet emerged in the observed temperature record.