Orographic effects on the northwestern Pacific monsoon: Role of air-sea interaction

[1] Orographic effects on northwestern Pacific climate are investigated with atmospheric and coupled oceanatmosphere general circulation models. In response to the removal of global orography, both models simulate a widespread decrease of summer rainfall over the Asian Continent. Over the subtropical northwestern Pacific, however, the response is opposite between the atmospheric and coupled models during spring and early summer. Sea surface temperature (SST) cooling is responsible for these differences between the atmospheric and coupled response. The SST cooling is triggered by winter stationary wave response to the mountain removal and amplified during spring by the wind-evaporation-SST feedback, altering the atmospheric response through summer. These results illustrate the importance of air-sea interaction and provide useful guidance for interpreting paleoclimate changes in response to the uplift of the Tibetan Plateau and Rift Valley of Africa. Citation: Okajima, H., and S.-P. Xie (2007), Orographic effects on the northwestern Pacific monsoon: Role of air-sea interaction, Geophys. Res. Lett., 34, L21708, doi:10.1029/2007GL032206.