"Local and remote controls on observed Arctic warming" by J.A. Screen, C. Deser & I. Simmonds, GRL 39 (2012); doi:10.1029/2012GL051598

Geophysical Research Letters, 39 (21012) L10709; doi:10.1029/2012GL051598

Local and remote controls on observed Arctic warming

Key Points

• Arctic troposphere has warmed at all heights, but most strongly near the surface
• Sea ice loss and local SST changes are central to near-surface Arctic warming
• Remote SST changes are the main driver of Arctic warming aloft (above 700 hPa)

J. A. Screen (School of Earth Sciences, University of Melbourne, Melbourne, Victoria, Australia), C. Deser (Global and Climate Dynamics, National Center for Atmospheric Research, Boulder, CO, USA) and I. Simmonds (School of Earth Sciences, University of Melbourne, Melbourne, Victoria, Australia)

Abstract

The Arctic is warming two to four times faster than the global average. Debate continues on the relative roles of local factors, such as sea ice reductions, versus remote factors in driving, or amplifying, Arctic warming. This study examines the vertical profile and seasonality of observed tropospheric warming, and addresses its causes using atmospheric general circulation model simulations. The simulations enable the isolation and quantification of the role of three controlling factors of Arctic warming: (1) observed Arctic sea ice concentration (SIC) and sea surface temperature (SST) changes; (2) observed remote SST changes; and (3) direct radiative forcing (DRF) due to observed changes in greenhouse gases, ozone, aerosols, and solar output. Local SIC and SST changes explain a large portion of the observed Arctic near-surface warming, whereas remote SST changes explain the majority of observed warming aloft. DRF has primarily contributed to Arctic tropospheric warming in summer.

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Received 4 March 2012; accepted 22 April 2012; published 30 May 2012.

http://www.agu.org/pubs/crossref/2012/2012GL051598.shtml