热带海温对纵向岭谷区5月降水年际变化的影响研究

 利用主成分分析和典型相关分析方法,研究了纵向岭谷区76个站点5月份降水场与其前期(12~4月)和同期(5月份)热带海温距平场之间的相关关系.其中,资料选用了1961~2001年共41 a的数据资料.研究结果表明,纵向岭谷区5月降水与热带海温距平场以同期相关为最好,而前期热带海温距平场除12月、3月和4月外,其它月份即1月、2月均有很好的相关.通过对热带海温距平场及降水场典型特征向量的分布作分析,太平洋暖池区热带海温与纵向岭谷区5月降水有正相关关系,赤道东太平洋海温与纵向岭谷区5月降水有负相关关系.当太平洋Walker环流增强时,纵向岭谷区5月降水增多;当Walker环流减弱时,纵向岭谷区5月降水减少.

The impact of tropical sea surface temperature on May rainfall over longitudinal range-gorge region

With corresponding data from 1961 to 2001,the relationship between rainfall in May over Longitudinal Range-Gorge Region(LRGR) and previous and current tropical sea surface temperature anomaly(SSTa) was studied with principal component analysis and canonical correlation analysis.The results show that there is the closest relation between the rainfall in May and current tropical SSTa;there is closer relation between the rainfall in May and tropical SSTa in previous January and February.The correlation between the rainfall in May and tropical SSTa over western Pacific is positive,but that over tropical eastern Pacific is negative,which implies that,when walker cell over Pacific is stronger,the May rainfall over LGRG increases.On the contrary,when walker cell over Pacific is weaker,the opposite condition will happen.