厄尔尼诺/拉尼娜与淮河流域汛期降水年际关系的稳定性分析

Stability Analysis of the Interannual Relationship Between E1 Ni?o/La Ni?a and the Summer Rainfall over Huaihe River Basin

根据1961-2015年淮河流域170站月降水资料、NCEP再分析资料和ERSST海温资料,采用滑动相关、合成分析等方法来探讨厄尔尼诺/拉尼娜与淮河流域汛期降水年际关系的稳定性。结果表明:厄尔尼诺/拉尼娜与淮河流域汛期降水的年际关系存在不稳定性,两者11年滑动相关在1979年出现一次突变,1961-1979年两者为明显的负相关,1980-1992年为正常阶段,1993-2015年为明显的正相关。文中主要讨论两个明显相关时段厄尔尼诺/拉尼娜对淮河流域降水的影响。1961-1979年时段和1993-2015年时段厄尔尼诺/拉尼娜对淮河流域夏季降水的影响是相反的,而且1993-2015年厄尔尼诺/拉尼娜对淮河流域汛期降水预测的指示意义不如1961-1979年时段。厄尔尼诺事件对淮河流域降水的影响较为明显,而拉尼娜的影响不明显,两者的影响表现出不对称的特点。1961-1979年期间厄尔尼诺发展(衰减)年夏季亚洲大气环流配置有利于南北气流在淮河流域上空汇合(辐散),使得流域降水偏多(偏少),而1993-2015年厄尔尼诺事件则相反。

Based on the monthly rainfall of 170 stations over Huaihe River Basin, NCEP reanalysis data and ERSST sea surface temperature data, the stability of the variation characteristics of the relationship between El Nio/La Nia and the summer rainfall over Huaihe River Basin is studied by using sliding correlation, composition analysis etc. It shows that the relationship between El Nio/La Nia and the summer rainfall over Huaihe River Basin is not stable, the 11 year slide correlation probably mutates in 1979.It is significant negative correlation between El Nio/La Nia and the summer rainfall over Huaihe River Basin during 1961-1979, and it is normal correlation during 1980-1992, but it is significant positive values during 1993-2015. The influences of El Nio/La Nia on the precipitation over the Huaihe River Basin during two obvious correlation periods are mainly discussed. The influences of El Nio/La Nia on the precipitation over the basin during 1961-1979 and 1993-2015 are on the opposite. And the El Nio/La Nia events during 1993-2015 as a predictor of the summer precipitation over the Huaihe River Basin are weaker than the El Nio/La Nia events during 1961-1979. The influence of El Nio events on the precipitation over Huaihe River Basin is obvious, but the influence of La Nia events is not obvious, and the influences of both are asymmetrical. The distribution of Asian atmospheric circulation in El Nio developing （decaying） summer during 1961-1979 is conductive to the north and south air convergence （divergence） over the Huaihe River Basin, which makes the precipitation over the basin more （less） than normal. While the El Nio events are on the opposite during 1993-2015.