Feedbacks Affecting Polar Amplification

Introduction

Most of the existing coupled ocean-atmosphere models show significantly warmer climate in the Arctic in certain runs (IPCC). One obvious and very important candidate for explaining this pattern, the so-called polar amplification, is snow/ice albedo feedback. Snow/ice covered surfaces reflect more sunlight than bare soil, therefore, the presence of snow/ice reduces the amount of solar radiation absorbed by the surface. This feedback works in a destabilizing manner on our climate system: the less (or more) snow/ice there is on the surface - the less (or more) energy gets reflected to the outer space and therefore the warming (or cooling) tendency on the surface becomes stronger.

The figure shows the future climate projection for the Arctic from five Arctic Climate Impact Assessment (ACIA) models (upper panel). The lower panel shows a measure of "disagreement" between the models. The variance in representation of the modern climate across models is shown. Disagreement is of the same order of magnitude as the climate change signal. Diagnosing the reasons for climate change in the Arctic will help reduce the uncertainty.

Principal Investigators

V.A. Alexeev, IARC, UAF, USA
S. Vavrus, University of Wisconsin

Participants

V.A. Alexeev, IARC
J.R. Bates, University of Copenhagen, Denmark
P.L. Langen, University of Copenhagen, Denmark
C. Murray, IARC
S. Vavrus, University of Wisconsin
J. Walsh, IARC

Other Organizations Involved

University College Dublin, Ireland
University of Copenhagen, Denmark
University of Wisconsin, USA

Collaborations

Bergen University (N.-G. Kvamstoe, Oe. Byrkjedal, E. Kolstad)

National Science Foundation Some of the material on this website is based upon work supported in part by the National Science Foundation under Agreement No. ARC-0327664. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.