Evaluating the Brewer–Dobson circulation and its responses to ENSO,QBO,and the solar cycle in different reanalyses

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摘要 Thisstudycomparestheclimatologyandlong-termtrendofnorthernwinterstratosphericresidualmeanmeridionalcirculation(RMMC),aswellasitsresponsestoElNi?o-SouthernOscillation(ENSO),stratosphericQuasiBiennialOscillation(QBO),andsolarcycleintenreanalysesandastratosphere-resolvingmodel,CESM1-WACCM.TheRMMCisalarge-scalemeridionalcirculationcellinthestratosphere,usuallyreferredtoastheestimateoftheBrewerDobsoncirculation(BDC).ThedistributionoftheBDCisgenerallyconsistentamongmultiplereanalysesexceptthattheNOAAtwentiethcenturyreanalysis(20RC)largelyunderestimatesit.Mostreanalyses(exceptERA40andERA-Interim)showastrengtheningtrendfortheBDCduring1979–2010.AllreanalysesandCESM1-WACCMconsistentlyrevealthatthedeepbranchoftheBDCissignificantlyenhancedinElNi?owintersasmorewavesfromthetropospheredissipateinthestratosphericpolarvortexregion.AsecondarycirculationcelliscoupledtothetemperatureanomaliesbelowtheQBOeasterlycenterat50hPawithtropicalupwelling/coolingandmidlatitudedownwelling/warming,andsimilarsecondarycirculationcellsalsoappearbetween50–10hPaandabove10hPatobalancethetemperatureanomalies.ThedirectBDCresponsetoQBOintheupperstratospherecreatesabarriernear30°Ntopreventwavesfrompropagatingtomidlatitudes,contributingtotheweakeningofthepolarvortex.TheshallowbranchoftheBDCinthelowerstratosphereisintensifiedduringsolarminima,andthedownwellingwarmstheArcticlowerstratosphere.ThestratosphericresponsestoQBOandsolarcycleinmostreanalysesaregenerallyconsistentexceptinthetwo20CRs.
机构地区 不详
出版日期 2019年02月12日(中国期刊网平台首次上网日期,不代表论文的发表时间)
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