青藏高原-热带印度洋地区大气热源的时空变化特征

为了寻求青藏高原一热带印度洋地区大气热源空间变化的敏感区，进一步深入研究季风的形成、变异和预测，利用NCEP1979-2008年的再分析资料计算分析了青藏高原一热带印度洋地区30年来不同季节大气热源分布的气候特征，并且利用经验正交函数分解研究了该区大气热源在夏、冬季的时空变化特征。结论如下：春季大气热源有明显的经向差异；夏季的热源明显比春季的热源强度强，范围广，热源最强中心在孟加拉湾北部大陆边缘；秋季热源区域明显南缩，热源强度较夏季明显减弱；冬季大气热源呈西西南一东东北方向分布，大气热源位置继续南移。对于夏季，前3个模态分别反映了青藏高原一热带印度洋地区大气热源的纬向差异型、经向差异型、西北一东南分布型。对于冬季，前3个模态分别反映了青藏高原一热带印度洋地区大气热源的经向差异主导型、经向差异型、纬向差异型。

Characteristics of Temporal and Spatial Variation of Atmospheric Heat Sources over the Tibetan Plateau-Tropical Indian Ocean

To explore sensitive areas of spatial variation of atmospheric heat sources over TPTIO region, as well as lu- cubrate the formation, variation and prediction of the Monsoon, by utilizing NCEP data of the Tibetan Plateau-Trop- ical Indian Ocean region from December1978 to November 2008, the climate characteristic analysis of the distribution of atmosphere heat sources in different seasons in the past 30 years is conducted and characteristics of temporal and spatial variation of atmospheric heat sources in summer and winter in this region are studied through empirical orthog- onal function. The results can be concluded as follows： Atmospheric heat sources have obvious meridional differences in spring; they are obviously stronger and broader in summer with the strongest heat source center in the northern continental margin of the Bay of Bengal than they are in spring; they move southward and reduce in autumn with their intensities weakening; and in winter, their locations continue to move southward and their distribution pattern is west southwest-east northeast direction. For summer, the first two modes, respectively, reflect the distribution of different anomalies in zonal direction, meridional direction and the third mode shows northwest-southeast distribu- tion. And in winter, the first three modes, respectively, show the distribution of different anomalies in meridional- based direction, meridional direction and zonal direction.