太平洋海温异常对大理雨季开始期的影响

采用大理州雨季开始期资料、1961年6月~2008年5月太平洋5°×5°共286个格点的逐月平均海温资料及NCEP/NCAR的SSTA资料,通过相关分析发现,太平洋海温与大理雨季开始期的关系密切,春季和上年秋季太平洋海温对大理雨季开始的影响较大。雨季开始前若发生厄尔尼诺事件,大理雨季开始期偏晚,反之,若发生拉尼娜事件,大理雨季开始期偏早。N ino3区的海温异常对大理雨季开始期的影响相当明显,当5月N ino3区的海温异常偏高时,大理雨季开始期偏晚;反之,当5月N ino3区的海温异常偏低时,大理雨季开始期偏早,N ino3区海温异常可以作为大理雨季开始期预测的一个强信号因子。

THE EFFECTS OF ANOMALOUS SEA-SURFACE TEMPERATURE OF PACIFIC OCEAN ON THE BEGINNING OF RAINY SEASON IN DALI

The beginning of rainy season in Dali and mean monthly sea-surface temperature of the Pacific Ocean from June 1961 to May 2008 on 286 grid points by 5 ×5 and SSTA from NCEP/NCAR were used. We used correlation analysis to search the relationship between SST of Pacific Ocean and the beginning of Rainy season in Dali. It shows that they have a close relationship. SST of Pacific Ocean in the spring and last autumn have a strong effect on the beginning of rainy season in Dali. When an E1 Nino event occurs before rainy season begin, the beginning of rainy season in Dali will be later. On the contrary, when a La Nina event occurs before rainy season begin, the beginning of rainy season in Dali will be earlier. Especially, we find that anomalous SST of Nino3 has a very strong effect on the beginning of rainy season in Dali. When SST in May of Nino3 is higher than usual, the beginning of rainy season in Dali will be later. Otherwise, SST in May of Nino3 is lower than usual, the beginning of rainy season in Dali will be earlier. So the abnormality of SST in Nino3 can be seemed as a strong signal and factor to forecast the beginning of rainy season in Dali.