Bymeansofsimulationexperimentswithatwo-dimensionalzonal-meanmodel,astudyismadeoftheinfluenceofthewesternNorth-Pacificmidlatitudesea-surfacetemperature(SST)anomaliesonthecirculationpatternandwet-seasonalprecipitationovertheEast-ChinaChangjiang-HuaihereachesandtheNorth-Chinaplain.TheSSTanomaliesarepidedintotwotypes,onebeing“colderinthesouthandwarmerinthenorth”andtheotherjustopposite,dependingonseason.Resultsshowthattheoccurrenceoftheanomaliesisfollowedbyconsiderablechangesinthepositionofthesubtropicalhighhappeningfor3-5monthstocome.Forinstance,thespring“colderinthesouthandwarmerinthenorth”anomaloustype(i.e.,colderfor20—35°N,andwarmernorthof35°N)leadstotheintensificationofthesummersubtropicalhigh,withtheridgelinemovedslightlynorthward,resultingindroughtoverChangjiangreachesforJuly-AugustandinexcessiverainfallintheNorth-Chinaplain,andviceversa.
