Location
MC 5501
Speaker
Karen Smith
Associate Professor, Teaching Stream
Director of Master of Science Program
Department of Physical and Environmental Science
University of Toronto Scarborough
Title
Ultrafast Arctic Amplification and its Governing Mechanisms
Abstract
Arctic amplification (AA), defined as the enhanced warming of the Arctic compared to the global average, is a robust feature of historical observations and simulations of future climate. Despite many studies investigating AA mechanisms, their relative importance remains contested. Recent work in our group examines the different timescales of these mechanisms to improve our understanding of AA’s fundamental causes. In CMIP5 models and the Community Earth System Model v1, Large Ensemble configuration (CESM-LE) we find that AA emerges almost immediately following an instantaneous quadrupling of CO2 increase and before any significant loss of Arctic sea ice has occurred. Through a detailed energy budget analysis of the atmospheric column, we determine the time-varying contributions of AA mechanisms over the simulation period and show that AA emerges as a rapid response to radiative forcing.