北非感热年际变化与中国东部降水的遥相关

基于NCEP/NCAR月平均再分析资料和中国160站降水资料,根据春季全球54 a(1951—2004年)感热的变化特征,经研究发现北非是春季感热异常关键区,且北非春季的地表感热对中国东部夏季的降水存在着滞后影响,与华北地区和江淮流域的降水分别呈较好的正相关和负相关,当北非感热正异常时,华北地区降水异常偏少,江淮流域降水异常偏多;当北非感热负异常时,华北地区降水明显偏多,江淮流域降水明显偏少。北非春季感热对中国东部夏季降水的影响作用和物理机制有进一步研究的价值。

Correlation analysis between the decadal character of sensible heat in north Africa and rainfall in east China

Based on NCEP/NCAR monthly reanalyze and rainfall data at 160 stations of China, the effects of sensible heat character in north Africa on the rainfall in east China are investigated. The results show that north Africa region is identified as the key area, its sensible heat has a lagged impact on summer rainfall, which means that positive anomaly leads to less rainfall in north China and more rainfall in Yangtze River, and vice versa. The possible mechanism is that the sensible heat anomaly causes the circulation wave train to superimpose on the westerly belt, which results in downstream effects so as to affect the distribution of summer precipitation. Therefore, the sensible heat in north Africa would be considered as one of the significant signal for the predicting of the summer rainfall in east China.