前期印度洋海温异常对中国春季降水的影响

为了进一步认识印度洋海温的异常变化与中国降水的关系,采用SVD分析、相关分析及合成差值分析讨论了前期冬季关键区海温的异常变化对中国春季降水影响的差异,探讨了产生这种影响的原因。结果表明:前期冬季关键区海温的异常增高(降低),会造成后期春季中国华北往南到华中、华东、华南东部及西北的新疆地区的降水明显增多(减少),西南的四川、贵州及华南的广西等地降水会有所减少(增多)。与关键区冷年相比,在关键区的暖年,环流形势反映出东欧槽显著减弱,北方气压显著降低,蒙古高压明显减弱,冷空气南下更为明显,而华南东部、华中、华东及华北一直被较为显著的南风气流控制,海洋的暖湿气流向中国内陆输送更为显著,使得东部及中部大部分地区水汽较为充沛,形成大面积的降水。

The Influence of the Preceding SST of Indian Ocean on the Spring Precipitation in China

In order to further understand the relationship of the Indian Ocean surface temperature anomalies and pre- cipitation in China, we used the SVD analysis, correlation analysis and synthesis to discuss the differences of the im- pact of SST anomalies of key area in early winter on China spring rainfall. The underlying reasons for this impact were investigated.. The results showed that： the increase （decrease） of SST anomalies of key area in early winter will result in the significantly increase （decrease） of precipitation of south to central, eastern, eastern South China, and northwestern Xinjiang in the late spring, and decrease of precipitation of Sichuan, Guizhou and Guangxi in South China. Comparing with the cold year of key area, in the warm years of key area, the circulation pattern reflects the significantly weakening of Eastern European slot and significantly decreasing of pressure in the north of China and the high pressure in Mongolia; the cold air going southward is more obvious; the eastern of South China, Central China, Eastern and Northern China has been more significantly controlled by the southward air flow; the ocean warm air transportation to inland is more significant, making water vapor in most parts of eastern and central China more abundant, forming a large area of !0reciDitation.