Title: Rapid Changes in Arctic Climate: Driving Forces and Possible Influences
Abstract: Rapid climate change has occurred in the Arctic, which is representatively indicated by a decade-long accelerated decline of sea ice extent and volume and an amplified warming trend at a rate of almost twice the global average. Along with these changes, extreme climate events of sea ice cover loss also occurred in summer 2007, 2012, and 2016. At the same time, dramatic changes have also occurred in broader areas of the Northern Hemisphere, including a spatial shift of the maximum surface air temperature warming trends from the Eurasian continent to the central Arctic Ocean, an enhancement of poleward oceanic and atmospheric heat transport from either the North Atlantic or North Pacific Ocean into the Arctic, a poleward shift of storm tracks and an intensification of Arctic storm activities, and a widespread of extreme cold weather and snow storms from the US east coast to Europe and Asia. Many aspects of these changes are obviously beyond the scope of conventional climate fluctuations, and also could not be solely accounted for by greenhouse-gas-emissions forcing. In this seminar, we will synthesize our research progresses from data analysis and model simulations towards improving understanding of the rapid changes in the Arctic and the enhanced linkage between Arctic and midlatitude climate and weather. The specific results include how changes in the atmospheric circulation and storm tracks orchestrate systematic changes across different Arctic climate components, and link Arctic climate changes to midlatitude climate and weather.