Basedonourpreviouswork,thewinterseasurfacetemperature(SST)intheKuroshioExtension(KE)regionshowedsignificantvariabilityoverthepastcenturywithperiodsof~6abetween1930and1950and~10abetween1980and2009.HowtheactivityoftheAleutianLow(AL)inducesthisdual-periodvariabilityoverthetwodifferenttimespansisfurtherinvestigatedhere.Forthe~6aperiodicityduring1930–1950,negativewindstresscurl(WSC)anomaliesinthecentralsubtropicalPacificassociatedwithanintensifiedALgeneratepositiveseasurfaceheight(SSH)anomalies.Whenthesewind-inducedSSHanomaliespropagatewestwardstotheeastofTaiwan,Chinatwoyearslater,positivevelocityanomaliesappeararoundtheKuroshiototheeastofTaiwanandthenthemeanadvectionviathiscurrentofvelocityanomaliesleadstoastrengthenedKEjetandthusanincreaseintheKESSToneyearlater.Forthe~10aperiodicityduring1980–2009,anegativeNorthPacificOscillation-likedipoletakes2–3atodevelopintoasignificantpositiveNorthPacificOscillation-likedipole,andthisprocesscorrespondstothenorthwardshiftoftheAL.NegativeWSCanomaliesassociatedwiththisALactivityinthecentralNorthPacificareabletoinducethepositiveSSHanomalies.TheseoceanicsignalsthenpropagatewestwardintotheKEregionafter2–3a,favoringanorthwardshiftoftheKEjet,thusleadingtothewarmingoftheKESST.ThefeedbacksoftheKESSTanomalyontheALforcingarebothnegativeforthesetwoperiodicities.Theseresultssuggestthatthedual-periodKESSTvariabilitycanbegeneratedbythetwo-wayKE-SST-ALcoupling.
