简介：AsalientfeatureoftheEastAsianorographyisthehugeTibetanPlateauinthewestandthebroadPacificintheeast.ReversalsinthetemperaturegradientbetweentheEurasiancontinentandtheadjacentPacificOceanassociatedwiththeprogressionoftheseasonshaveproducedtheprominentEastAsianmonsoonsystem.Thesummermonsooncontributesabout49%oftheannualprecipitationoverEastAsia.Anomalousmonsoonactivitieshaveandwillcontinuetoaffectmorethanonebillionpeoplelivinginthisarea(ZhouTJetal.,2009,2011).

简介：TheuniquegeographicallocationandhighaltitudeoftheTibetanPlateaucangreatlyinfluenceregionalweatherandclimate.Inparticular,theAsiansummermonsoon(ASM)anticyclonecirculationsystemovertheTibetanPlateauisrecognizedtobeasignificanttransportpathwayforwatervaporandpollutantstoenterthestratosphere.Toimproveunderstandingofthesephysicalprocesses,amulti-locationjointatmosphericexperimentwasperformedovertheTibetanPlateaufromlateJulytoAugustin2018,fundedbythefiveyear(2018–2022)STEAM(stratosphereandtroposphereexchangeexperimentduringASM)project,duringwhichmultipleplatforms/instruments—includinglong-durationstratosphericballoons,dropsondes,unmannedaerialvehicles,specialsoundingsystems,andground-basedandsatellite-borneinstruments—willbedeployed.Thesecomplementarymethodsofdataacquisitionareexpectedtoprovidecomprehensiveatmosphericparameters(aerosol,ozone,watervapor,CO2,CH4,CO,temperature,pressure,turbulence,radiation,lightningandwind);therichnessofthisapproachisexpectedtoadvanceourcomprehensionofkeymechanismsassociatedwiththermal,dynamical,radiative,andchemicaltransportsovertheTibetanPlateauduringASMactivity.

简介：PrecipitationobservationscollectedatweatherstationsineasternChina,theNCEP/NCARreanalysisdata,thetropicalcyclone(TC)BestTrackDataset,andasensitivitynumericalexperimentwereusedinthepresentstudytoinvestigatetheroleintheEastAsiansummermonsoon(EASM)systemplayedbyfrequentTCactivitiesoverthewesternNorthPacific(WNP).Resultsindicatedthat,inactiveTCyears,theEASMisstrongerandthesoutherlywindsinthelowertroposphereadvancefarthernorthandreachhigherlatitudes.Meanwhile,themonsoonrainbeltremainsinthelowerandmiddlereachesoftheYangtzeRivervalleyforarelativelyshortperiod,leadingtolessprecipitationthere.BoththewesternPacificsubtropicalhighandtheSouthAsianhighweakenwiththenorthwardshiftoftheridgelinesforbothhigh-pressuresystemsaswellastheEastAsiansubtropicalupper-leveljet.Therefore,theimpactsoffrequentTCactivitiesovertheWNPoneachindividualcomponentoftheEASMareinphasewiththoseofthestrongerEASMitself,amplifyingfeaturesofthealreadystrengthenedEASM.

简介：Usingfoursatellitedatasets(TOMS/SBUV,OMI,MLS,andHALOE),weanalyzetheseasonalvariationsofthetotalcolumnozone(TCO)anditszonaldeviation(TCO*),andrevealtheverticalstructureoftheOzoneLow(OV)overtheAsiancontinent.Ourprincipalfindingsare:(1)TheTCOovertheAsiancontinentreachesitsmaximuminthespringanditsminimumintheautumn.TheOzoneLowexistsfromMaytoSeptember.(2)TheOzoneLowhastwonegativecores,locatedinthelowerandtheupperstratosphere.Thelowercoreisnear30hPainthewinterand70hPaintheotherseasons.Theuppercorevariesfrom10hPato1hPaamongthefourseasons.(3)ThepositionoftheOzoneLowinthelowerandtheupperstratosphereovertheAsiancontinentshowsseasonalvariability.