北京雷暴大风日环境特征分析

©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.[J].,14(1):54262.LiaoXiaonong.AnalysisonenvironmentalconditionforwindgustinBeijingarea[J].ClimaticandEnvironmentalResearch(inChinese),14(1):54262.2008201203,2008203203Z00062790401912005BA904B05,,1962,,,E2mail:cristinlxn@1261com,1000892120002007,,,,,,,(DCAPE),600Jkg-1,86%59%DCAPE,,,,,,,,,100629585(2009)0120054209P445AAnalysisonEnvironmentalConditionforWindGustinBeijingAreaLIAOXiaonongBeijingMeteorologicalObservatories,Beijing100089AbstractWindgustiscausedbytheconvectivecloudandisdifferentfromthetornado.Basedontherainfall,thewindgusteventsaredividedintotwokinds,i1e.,thedryandthewetones.Theinstabilityandenvironmentalwindperpendiculardistributionwithinthetroposphereinthewindgustdaysareanalysedrespectively.Theresultsindi2catethattheenvironmentalconditionissomedifferentforthesetwokindsofevents.Indrywindgustdays,theval2ueofconvectiveavailablepotentialenergyisverylowbuttheverticalwindshearbelow6kmisgreat.So,thedy2namicinstabilityduetothestrongwindshearplaysanimportantroleintheconvectivedevelopmentinthesedays.Andtheutilizationofinstabilityindexesinconvectiondevelopmentforecastisrestricted.However,theconvection©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(notonlydrybutalsowetones)developwhenthedowndraftconvectiveavailablepotentialenergyishigherthan600Jkg-1andthevalueincreasesbeforethestrongwindapproach,whichisalsouseful.Priortothewindgust,theenvironmentallapserateoftemperaturebelowtheliftingcondensationlevelalsorisesobviously.Besides,theprofilerdataaresup2plementarytothesounding.Insomeevents,theisotachinhighervaluegoesdowncontinuouslyandreachesthesur2facewhilethegustbreaksout.Iftheprofilerdatacouldbeusedeffectively,thenowcastingandwarningforthewindgustmightbeimproved.Keywordswindgust,(downdraft)convectiveavailablepotentialenergy,windperpendiculardistribution,pro2filer1,8(1719ms-1),,,(),,,(),,,6,F0F5,,,F3(Fujita,1976;Fujitaetal.,1981),,,,,(Fujitaetal.,1977),198331,31212,148,110(,2001)21,,(,2006b;,2007;,2005;,2007),,(2006)NCEP(CAPE)(CIN),CAPE,CIN(2006)3,:,,,,,,(Roger,1985),,,55©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(1985),41,(),14,27,411NCEP(6min),(CAPE)(DCAPE)2,(CAPE,EC),,EC=gZELZLFCTvp-TveTvedz,(1),Tv,epZLFCZEL,211,(1)()CAPE14,910,12CAPE100Jkg-1CAPE,12(2),2717CAPE1000Jkg-1,6310%,92000Jkg-1,,CAPE,,CAPE212,V(1a),850hPa17,,20,700hPa,700500hPa,47,600hPa,500hPa730hPa(1b),1Table1ConvectiveavailablepotentialenergyatapproachingtimeofdrywindgustdaysJkg-1CAPECAPE10802201793581536516107391740117195012067512131715701460132Table2ConvectiveavailablepotentialenergyatapproachingtimeofwetwindgustdaysJkg-1CAPECAPECAPE1426121021031919141614279616119201420624193205317124041121241816411921913138719221597135268018141716192324211961826121528181424151019786012161751122525891788711517216210262151494581718281910275561065©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.:(a);(b)Fig11Theaveragesoundingofwindgustdays:(a)dry;(b)wet,700hPa,811700hPa,700250hPa1213,200hPa16870hPaCAPE[(1)],,CAPECAPE,,,,,3DCAPEDCAPE(ED),ED=pnpiRd(Te-Tp)dp,(2),T,ep,pi(i),pn(n)-wmax=2ED,(3)(2)(3),,DCAPE,,6h()DCAPE(34),DCAPE,DCAPE(1412)16DCAPE,DCAPE3Table3DowndraftconvectiveavailablepotentialenergyindrywindgustdaysJkg-1DCAPEDCAPE156310603138146411163716215541766710915910684123761711571310867161691174751438717115811959517514411655171280017152110651215147215131202121059177470131405171410821211851275©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(,2006a),,CAPE,,,CAPE,,06km(5),1010ms-1,11,2710ms-1812,CAPE,,8(12)2(5910m)(150m)2,138min,,,5Table5Theabsolutevalueofwindvectordifferenceindrywindgustdaysms-111714861921916916193916101211426171127105181612410610