非均匀下垫面大气边界层的观测和数值模拟分析

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1、AbstractInthesummerof2005andthespringof2006，fluxmeasurementsweretwicetakeninurbanNanjing(MunicipalPartySch001)andsuburbanNanjing(Pukouarea)．Heatflux，latentheatflux，carbondioxidefluxaswellasfrictionvelocitywereobtainedapplyingtheeddy—covariance(EC)technique．I

2、nordertoeliminatetheimpactofcomplexterrain，aplanar-fit(PF)methodfortiltcorrectionwasadopted．AthoroughanalysisofthePFmethodindicatedthatPFcoefficientsarecloselyrelatedtowinddirection．Thus，winddirectionsmustbetakenintoconsiderationwhenprocessingdata．Tobespecif

3、ic，windsfromalldirectionsweredividedintoseveralsectorsandPFmethodwasappliedtoeachoftheminordertogenerateafiredplaneforeachsector．ThismethodWasnamedsectorplanarfit(spF)asdistinguishedfromthegeneralplanarfit(GPF)whichdoesnotconsiderwindsectors．Thedifferencesof

4、correctedfluxesbythetwomethods(GPF／SPF)forthetwoseasonsandtwolocationsweremainlyconsidered．Itwasclearlyrevealedthatbothurbanandsuburbanfluxresultsshareaconsistenttrendinspringandsummer；geographically，inurbanareas，thecorrectedfluxesusingSPFandGPFshowobviousdi

5、fferences．Differencesaremuchsmallerinsuburbanareas．Moreover,theverticalvelocity(w)wascorrectedusingthetwomethodsanditwasfoundthatWalsoexhibitssignificantdifferences．Finally,accordingtotheprobabilitydistributionofcorrectedverticalwindvelocitybythetwomethods，i

6、twasconcludedthatdistributionofcorrectedverticalvelocitiesbySPFiSclosertonormalthanGPF．Afterobservingthecomplicatedunderlyingsurfaceandnear-surfacelayerofurbanarea，ithasbeenfoundoutnecessarytoapplynumericalsimulationtechniquetofurtherinvestigatethefeaturesof

7、theconvectiveboundarylayer(CBL)affectedbyinhomogeneousunderlyingsurface．ThemesoscalemodelWRFfWeatherResearchandForecasting)anditslargeeddysimulation(LES)subroutinewaschosentostudythecharacteristicsoftheCBLdrivenbyinhomogeneoussurfaceheating．Different“Chessbo

8、ard-like’’patternswithpatchesofsurfaceheatfluxesattwofixedvaluesweredesigned．Theinhomogeneityscaleintwoschemesare5kilometersand2．5kilometers．Togetherwithhomogeneousunderlyingsurface，therearetota