夏季南亚高压对流层中上层异常暖中心时空分布特征及其激发的大气波动

利用1979年1月至2016年12月ERA-interim月平均再分析资料和CAMP全球月降水资料，分析夏季（6—8月）南亚高压下方500 hPa到100 hPa暖中心的时空分布，从三维结构来揭示夏季南亚高压暖心特征.回归分析进一步探讨青藏高原上空暖中心对全球大气环流产生的可能影响.结果表明：南亚高压在150 hPa达到最强，这一层也是异常冷暖中心分界面，150 hPa以下有一强大异常暖中心，异常暖中心位于300 hPa附近，150 hPa以上为异常冷中心，中心位置位于70 hPa附近.异常暖中心从500 hPa向上逐渐向西向北倾斜，异常暖中心面积200 hPa达最大，150 hPa异常暖中心消失，100 hPa以上转变为异常冷中心.500~200 hPa异常暖中心表现出不断增暖的长期趋势（1979—2016），100 hPa异常冷中心则表现出不断变冷的长期趋势（1979—2016）.去掉长期趋势的时间序列表现出明显的"准两年振荡"特征，异常暖中心位置在纬向上较稳定，在经向上表现出年际的"东西振荡".300 hPa异常暖中心是整个南亚高压的关键层.300 hPa异常暖中心对全球其他变量场进行回归分析.高度回归场表明，青藏高原上空异常暖中心在北半球中高纬度高度场上激发出3波的行星波，波特征在对流层中上层表现明显，波振幅随高度增高不断加强，在对流层中下层逐渐减弱并消失.纬向风回归场在对流层中上层表现出横跨南北半球的波列，这个波列在200 hPa振幅最大.经向风回归场在北半球中纬度（30°N—60°N）表现出7波型，说明南北能量交换频繁.降水回归场表明，东亚地区长江中下游至日本降水偏少，而其南北两侧降水偏多.

Spatial-temporal characteristics of the Asia High warm center and atmospheric waves excited by it in upper troposphere

Using ERA-interim monthly mean data from January 1979 to December 2016 and CAMP global monthly mean precipitation data, the spatial-temporal distribution of the warm center is analyzed from 500 hPa to 100 hPa under the Asia High and reveals the 3-D structures characteristics of the warm center in summer (June to August). Regression is utilized to further study the possible impacts of the warm center over Tibetan on the global air circulation. Results show: it is at 150 hPa for Asia High to get the strongest, this level is also an interface between the cold and the warm center. Under 150 hPa there is the warm region with the warmest center at 300 hPa as well as above 150 hPa there is cooling region with the coolest center at 70 hPa. The warm center declines towards northwest from 500 hPa to 200 hPa and becomes the biggest at the level of 200 hPa. The warm center disappears at 150 hPa and then the warm center switches to the cooling center at 100 hPa. The warm centers at different levels have a gradually increasing long-term trend above 500 hPa to 200 hPa during 1979 to 2016, while the cooling center at 100 hPa shows an obvious Quasi Biennial Oscillation (QBO) features. The latitude position of the warm center is relatively stable, however, the longitude position of the warm center takes on a "west-east oscillation" from year to year. The warm center at 300 hPa is the key level for the Asia High and has the close relationship with its upper levels and lower levels. Regression of the warm center at 300 hPa on the other variable fields reveal that the warm center over Tibetan Plateau excites 3-Rossby waves in height fields on the mid-high latitude in northern hemisphere. It is marked on the upper troposphere for the waves as well as the waves amplitude increase with the height increasing. The waves disappear on the lower troposphere. The zonal wind regression field shows there is a wave train across the equator, for these waves, the wave amplitudes are the biggest at 200 hPa. A 7-waves pattern is discovered for meridional wind regression field on mid-latitude (30°N—60°N) of Northern Hemisphere. That means there are frequently energy exchange between South and North. The precipitation regression field indicates there is decreasing water trend from mid-low Yangzi River basin to Japan as well as there are increasing water trend in South and North region of Yangzi River basin.