P1.17
Influence of the increased SST on baroclinic instability wave activities under the aqua planet condition
Chihiro Kodama, Tohoku Univ., Sendai, Japan; and T. Iwasaki
Global warmings have been recognized to change dynamical and thermodynamical states of the troposphere mainly through increasing SST. In the extratropics, baroclinic instability wave activities are of great interest under global warmings. Thus, we conduct a series of aqua planet experiments in order to study the influence of the increased SST on baroclinic instability wave activities in the troposphere. First experiment, named "GRA-3 run", is that the control SST is warmed by 3K only in the high latitudes. In the GRA-3 run, midlatitude meridional temperature gradient is decreased in the lower troposphere and the westerlies are suppressed in both the troposphere and stratosphere. Therefore, the eddy kinetic energy is decreased in the entire troposphere. Second experiment, "ALL+3 run", is that the control SST is homogeneously warmed by 3K all over the world. In the ALL+3 run, midlatitude meridional temperature gradient is increased in the upper troposphere and the westerlies are enhanced above the upper troposphere. Despite this, the eddy kinetic energy is generally decreased in the troposphere. These results suggest that the lower-tropospheric baroclinicity is more important for baroclinic instability wave activities in the troposphere.
Poster Session 1, Poster Session
Tuesday, 21 August 2007, 3:00 PM-5:00 PM, Hawthorne-Sellwood
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