摘要
The Jiang-Huai Meiyu rainy season can be distinguished into the Jiangnan Meiyu spell and the Huaihe Meiyu spell. The Jiangnan Meiyu spell appears on the last ten days in June and the Huaihe Meiyu spell lasts from early July to middle July. An inter-decadal transition was observed in 1998 respectively from the anomalies of Jiangnan Meiyu rainfall,the sea surface temperature (SST),and the subsurface tem-perature in the equatorial Pacific. Since the beginning of the 21st century,opposite trends and biennial oscillations of the Meiyu rainfall are observed in the Jiangnan and Huaihe basins. Before the strong La Nia of 1999―2000,the positive SST anomalies usually occurred in the eastern equatorial Pacific. Since the beginning of the 21st century,a precursory warming signal of SST anomaly comes from the subsurface temperature which is centrally exposed near the dateline in the central equatorial Pacific. The above-normal Meiyu rainfall in 2003,2005 and 2007 over the Huaihe basin followed the prior winter-spring positive SST anomaly near the dateline. A relationship shows that the more Jiangnan (Huaihe) Meiyu follows the winter-spring warm water in the eastern (central) equatorial Pacific.
The Jiang-Huai Meiyu rainy season can be distinguished into the Jiangnan Meiyu spell and the Huaihe Meiyu spell. The Jiangnan Meiyu spell appears on the last ten days in June and the Huaihe Meiyu spell lasts from early July to middle July. An inter-decadal transition was observed in 1998 respectively from the anomalies of Jiangnan Meiyu rainfall, the sea surface temperature （SST）, and the subsurface tem- perature in the equatorial Pacific. Since the beginning of the 21st century, opposite trends and biennial oscillations of the Meiyu rainfall are observed in the Jiangnan and Huaihe basins. Before the strong La Nina of 1999-2000, the positive SST anomalies usually occurred in the eastern equatorial Pacific. Since the beginning of the 21st century, a precursory warming signal of SST anomaly comes from the subsurface temperature which is centrally exposed near the dateline in the central equatorial Pacific. The above-normal Meiyu rainfall in 2003, 2005 and 2007 over the Huaihe basin followed the prior winter-spring positive SST anomaly near the dateline. A relationship shows that the more Jiangnan （Huaihe） Meiyu follows the winter-spring warm water in the eastern （central） equatorial Pacific.
基金
Supported jointly by National Basic Research Program of China (Grant No.2006CB403602)
the Chinese COPES (Grant Nos.GYHY20070605 and 2006BAC03B03)
关键词
长江流域
淮河流域
梅雨季节
赤道
温度
Yangtze River basin, Huaihe River basin, Meiyu, sea surface temperature, subsurface temperature, biennial oscillation
