Basedonthewinter1984/1985ECMWFgridpointdatasubjectedtothe30-60dayband-passfilteringandcompositeanalysis,astudyisundertakenoftheLFO(low-frequencyoscillation)structureintheeasternAsianwesterlyjetentranceandexitregionsandtheAsia-Pacificlow-frequencyvortexactivitycharacteristics.Resultsshowthatzonalwindoscillationsonbothsidesofthejetcoreareinanti-phase,incloserelationtotheE-Wdisplacementofthecore.RanginginNW-SEdirectionisalow-frequencyvortextrain(LFVT)emanatingfromUralviacentralAsiatoEastAsia.Alow-frequencyvortexofUralorigin,whenreachingaround50(?),80(?),issplitintotwoparts,onetravellingeastwardandtheothersouthward,andfinallytheyarcconnectedcyclonicallyoranticyclonicallyatlowlatitudes,form-ingavigorouslowfrequencycycloneoranticycloneintheeasternpartofChinamainland,completingafullcycleoftheLFVT.Further,observedinthecentralPacificareameridionalLFVTandacyclone/anticyclonecoupletloopinginacounterclockwisesense,givingrisetotheLFVTphaseshiftoverthisregion.
