学科分类
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1 个结果
  • 简介: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.

  • 标签: 周期响应 海温异常 Low 黑潮 北太平洋涛动 速度异常