【摘要】 利用西北地区东部1961 2009年99个气象测站逐月降水量资料,以及Hardley中心逐月海表面温度(SST)资料,采用最大协方差分析(MCA)、相关、回归等统计方法,考虑扣除ENSO(El Ni珘noSouthern Oscillation)影响后,分析了西北地区东部降水量和热带印度洋SST之间年际、年代际变化关系。结果表明:前期冬、春季持续异常的热带印度洋海盆模与西北地区东部5月降水异常主模态存在显著正相关关系,通常超前1~2个季节的暖(冷)海盆模对应5月西北地区东部降水偏多(少),并且这种显著关系存在年代际差异,20世纪70年代中期之前两者关系不显著,之后两者关系加强,通过了0.05显著性水平检验。热带印度洋海盆模对西北地区东部5月降水的影响可能是热带印度洋海盆模"电容器"效应的一种具体体现。更多还原

【Abstract】 M ost previous researches of Sea Surface Temperature Anomaly( SSTA) in the tropical Indian ocean influencing precipitation mainly focused on the eastern region of China. In recent years,the latest studies have found important climatic effects of the inter- annual first mode of the tropical Indian Ocean Basin M ode( IOBM). So it is necessary to study the influence of SSTA in the tropical Indian Ocean on precipitation anomaly of East of Northw est of China( ENC). Based on 99 meteorological stations monthly precipitation data in ENC,and monthly SST data of Had ISST data set from Hardley center during 1961- 2009,adopting M CA,correlation,regression and other statistical methods,the inter- annual and inter- decadal relationship betw een the precipitation in ENC and the tropical Indian ocean SST is analyzed in this article. It is found that the persisting anomaly of the IOBM in previous w inter and spring is significantly corrected w ith precipitation anomaly main mode in ENC in subsequent M ay. In further the relationship is difference before and after mid 1970 s,w hich being the climate shift year of north hemisphere. The relationship is not significant before mid 1970 s,w hile after mid 1970 s the relationship is strengthened and significant,w ith passing 95% significant test. Usually the w arm( cold) Basin mode in previous w inter and spring is corresponding to more( less) precipitation in subsequent M ay in ENC.The preliminary analysis is that the impact of the tropical Indian ocean basin mode on precipitation anomaly in ENC is a concrete manifestation of IOBM ‘Capacitor’effect.更多还原