经圈环流对定常波传播的影响
THE EFFECT OF MERIDIONAL CIRCULATION ON THE PROPAGATION OF STATIONARY ROSSBY WAVES
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摘要: 在一般斜压大气中,基本气流中包含经圈环流时,定常波传播不仅能穿过东风带,而且明显增强。在基流含有经圈环流的情况下,北半球中纬度地形强迫可引起低纬大气的显着响应,这表明经圈环流在中低纬定常响应的相互联系中起着重要作用;北半球中纬度热力强迫可产生类似北半球夏季季风环流的波列分布,这说明经圈环流在夏季季风环流的形成中起着一定的作用;在赤道东太平洋加热强迫情况下,在冬半球可引起PNA型的定常波传播波列,而在夏半球却没有明显的PNA特征。这表明经圈环流对冬、夏半球的定常波传播路径有着显着的影响。Abstract: In general baroclinic atmosphere, when the basic state includes meridional circulation. the stationary waves might not only pass through the equatorial easterlies, but also strengthen significantly. And the orographic forcing in Northern Hemisphere midlatitude might cause marked responses in low latitude atmosphere. This suggests that the meridional circulation play an important role in the connection of stationary responses in midlatitude and low latitude as a result of heating forcing in Northern Hemisphere midlatitude. The features sim- iliar to Northern Hemisphere summer monsoon circulation can be obtained. It appears that the meridional circulation play some roles in the forcing of summer monsoon circulation. The anomaly forcing locating at the eastern equatorial Pacific makes the stationary waves present PNA pattern in Winter Hemisphere, but it does not in Summer Hemisphere. It suggests that the meridional circulation has a marked influence on the route of stationary waves propagation in Winter and Summer Hemisphere.