Variability of Summer Monsoon Rainfall in India on Inter-Annual and Decadal Time Scales  

作　　者：Porathur Vareed JOSEPH Bindu GOKULAPALAN Archana NAIR Shinu Sheela WILSON 

机构地区：[1]Nansen Environmental Research Centre India

出　　处：《Atmospheric and Oceanic Science Letters》2013年第5期398-403,共6页大气和海洋科学快报（英文版）

基　　金：the European Commission(Project INDO-MARECLIM);the Norwegian Research Council(Project INDIA-CLIM)for providing financial support for this study

摘　　要：Indian Summer Monsoon Rainfall （ISMR） exhibits a prominent inter-annual variability known as troposphere biennial oscillation.A season of deficient June to September monsoon rainfall in India is followed by warm sea surface temperature （SST） anomalies over the tropical Indian Ocean and cold SST anomalies over the westem Pacific Ocean.These anomalies persist until the following monsoon,which yields normal or excessive rainfall.Monsoon rainfall in India has shown decadal variability in the form of 30 year epochs of alternately occurring frequent and infrequent drought monsoons since 1841,when rainfall measurements began in India.Decadal oscillations of monsoon rainfall and the well known decadal oscillations in SSTs of the Atlantic and Pacific oceans have the same period of approximately 60 years and nearly the same temporal phase.In both of these variabilities,anomalies in monsoon heat source,such as deep convection,and middle latitude westerlies of the upper troposphere over south Asia have prominent roles.Indian Summer Monsoon Rainfall(ISMR)exhibits a prominent inter-annual variability known as troposphere biennial oscillation.A season of deficient June to September monsoon rainfall in India is followed by warm sea surface temperature(SST)anomalies over the tropical Indian Ocean and cold SST anomalies over the western Pacific Ocean.These anomalies persist until the following monsoon,which yields normal or excessive rainfall.Monsoon rainfall in India has shown decadal variability in the form of 30 year epochs of alternately occurring frequent and infrequent drought monsoons since1841,when rainfall measurements began in India.Decadal oscillations of monsoon rainfall and the well known decadal oscillations in SSTs of the Atlantic and Pacific oceans have the same period of approximately 60 years and nearly the same temporal phase.In both of these variabilities,anomalies in monsoon heat source,such as deep convection,and middle latitude westerlies of the upper troposphere over south Asia have prominent roles.

关 键 词：Indian monsoon rainfall variability middle latitude westerly winds Asia Pacific wave global SST gradient 

分 类 号：P426.6[天文地球—大气科学及气象学]