Arctic Amplification and Sea Ice Loss

Presented by Till Wagner, Assistant Professor, Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison

Abstract: Arctic Amplification is the phenomenon by which the Arctic warms faster than the global average. Arctic Amplification is widely found in climate model simulations and reconstructions of past climate changes, but the instrumental record has received relatively little attention. In this talk, I will show that for much of the 20th century, the Arctic in fact cooled while the global-mean temperature rose. Two main causes for these opposing trends can be identified: The first is that regional cooling from aerosols counteracted the warming from greenhouse gases in the Arctic. The second is that natural fluctuations of the climate system manifested in a pattern of Arctic cooling under global warming. I will then turn to sea ice-ocean feedbacks that drive Arctic Amplification and will finally discuss the impact of sea ice loss on global temperatures (and modeling challenges in isolating this impact).