Monday, 23 January 2012: 4:15 PM
Origin of the Arctic Warming in Climate Models
Room 354 (New Orleans Convention Center )
There is a debate on whether the snow/ice change feedback or poleward energy transport from lower latitudes generates the observed Arctic warming amplification. There is another possibility that remotely induced warming in the Arctic can be amplified by snow/ice feedbacks. We demonstrate that this possibility plays an important role in two independent climate models: CAM3 and ECHAM5. We also show that the June-August temperature structure in the vertical is a good indicator of how much the climate forcing from lower latitudes contributes to the Arctic warming. In light of the June-August 3D temperature trend in ERA interim, both models, especially ECHAM5, as well as the IPCC AR4 models seem to over-simulate the transport mechanism. This has implications for the climate feedback gradient from the tropics to the Arctic in models.
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