We thank Ed Gerber and one anonymous reviewer for their thorough reviews of this manuscript, which greatly improved the earlier versions. We thank Luke Oman for performing the GEOS-5 model integrations and Dennis Hartmann and Dargan Frierson for their thoughts while this research was being performed. This work was supported by the Climate Dynamics Program of the National Science Foundation under Grant AGS-0960497 to the University of Washington and by the NASA Grant NNX06AE70G.
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