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Sea-ice loss seems to be the main culprit behind the rapid surface warming in the Arctic, but it contributes next to nothing to the heating of the area's lower atmosphere.
The climate is warming faster in the Arctic than elsewhere. Using simulations generated by two atmospheric circulation models, James Screen at the University of Melbourne in Australia and his team disentangled and quantified local and remote contributions to this 'Arctic amplification'.
Sea-ice retreat and related changes in local sea surface temperature are the main drivers of surface-level warming, the simulations suggest. By contrast, most lower atmosphere warming seems to result from increased atmospheric heat transport from lower latitudes. Apart from in July and August, greenhouse gases and aerosols make little direct contribution to Arctic warming, the authors note.
Geophys. Res. Lett. http://dx.doi.org/10.1029/2012GL051598 (2012)