低阶全球谱模式中地形对季节内振荡的影响

TOPOGRAPHIC INFLUENCE ON INTRASESONAL OSCILLATION IN THE LOW—ORDER GLOBAL SPECTRAL MODEL

使用三角形截断,截断波数为10的五层全球谱模式研究地形对季节内振荡的影响。分析了有地形和无地形模式模拟的一年带通滤波资料。结果表明,地形的作用在于加强了热带大西洋和印度洋的对流活动,从而加强了热带对流热源、汇的振荡强度;也加强了中、高纬季节内振荡的强度。还讨论了地形影响季节内振荡的机理。

Based on the triangle truncation at wavenumber 10,a study is made of the topographic influence on the intra—seasonal oscillation (ISO) in terms of a 5—level low—order global spectral model. Analysis of the one—year bandpass filtered data obtained by models with and without topography shows that the effect of topography lies in the intensification of convective activities in the tropical Atlantic and Indian Oceans, thus reinforcing the intensity of the oscillation of the tropical convective heat source/sink, and the extratropical ISO, In addition, the mechanism of the topographic influence on the ISO is examined herein.