简介：ThisstudyusesNCEP/NCARdailyreanalysisdata,NOAAoutgoinglong-waveradiation(OLR)data,thereal-timemultivariateMJO(RMM)indexfromtheAustralianBureauofMeteorologyandTibetanPlateauvortex(TPV)datafromtheChengduInstituteofPlateauMeteorologytodiscussmodulationoftheMadden-JulianOscillation(MJO)ontheTibetanPlateauVortex(TPV).Waveletandcompositeanalysisareused.ResultsshowthattheMJOplaysanimportantroleintheoccurrenceoftheTPVthatthenumberofTPVsgeneratedwithinanactiveperiodoftheMJOisthreetimesasmuchasthatduringaninactiveperiod.Inaddition,duringtheactiveperiod,thenumberoftheTPVsgeneratedinphases1and2islargerthanthatinphases3and7.Aftercompositingphases1and7separately,allmeteorologicalelementsinphase1areapparentlyconducivetothegenerationoftheTPV,whereasthoseinphase7aresomewhatconstrained.Withitseastwardpropagationprocess,theMJOconvectioncentrespreadseastward,andtheverticalcirculationwithinthetropicalatmospherechanges.Duetotheinteractionbetweenthemid-latitudeandlow-latitudeatmosphere,changesoccurinthebarocliniccharacteristicsoftheatmosphere,theavailablepotentialenergyandeddyavailablepotentialenergyoftheatmosphere,andthecirculationstructuresoftheatmosphereovertheTibetanPlateau(TP)andsurroundingareas.Thisresultsinsignificantlydifferentwatervapourtransportationandlatentheatdistribution.Advantageousanddisadvantageousconditionsthereforealternate,leadingtoasignificantdifferenceamongthenumbersofplateauvortexindifferentphases.

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简介：Strongasymmetricalvorticesappearontheleewardofslenderbodyathighanglesofattack,whichhasveryunfavorableeffectonthestabilityandcontroloftheaircraft.Amethodisdevelopedtocontrolthesideforceofslenderbodyathighanglesofattack,andisverifiedinwindtunnel.Athin-filmtriangularself-excitedoscillationflagisfixedatthetipoftheslenderbodymodelwhosesemi-apexangleis10°.Sideforceisapproximatelylinearlyproportionaltoroll-settingangleofself-excitedoscillationflagathighanglesofattack,andtheslopoffittingstraightlineobtainedbytheleastsquaremethodis-0.158.Thelinearrelationshipbetweensideforceandroll-settingangleprovidesconveniencefordevelopingsideforcecontrollawofslenderbodyathighanglesofattack.Experimentaldatashowsthatthesideforcecoefficientsvarylinearlywithroll-settingangleswhenaspecificplasticself-excitedoscillationflagisusedasthecontrolflag.Therangeofsideforcecoefficientandroll-settingangleare,respectively,-3.2to3.0and-20°to20°.Thedeviceissimple,effective,andisofgreatpotentialinengineeringapplication.

简介：Basedonobservationsandreanalysisdata,thecharacteristicsoftheevolutionofclimatologicalspringprecipitationoverSouthernChina(SPSC)andtheassociatedclimatologicalintraseasonaloscillation(CISO)andatmosphericcirculationarestudied.ResultsshowthatSPSCincreasesinanoscillatoryway.AlthoughtheevolutionofSPSCissimilarindifferentregions,therearealsodifferences.IndifferentregionsofSouthernChina,theonsetdatesoftherainseasonarefromthe12thto24thpentadandthepeakdatesareafterthe20thpentad.CISOisanimportantcomponentofSPSC,whichisnotonlystatisticallysignificant,butalsoaccompaniesadynamicallycoherentstructure.Thepeakwet/dryphaseofeachCISOcyclecorrespondstoasignificantrainfallincreasing/decreasingperiodandmodulatestheevolutionofSPSC.TherainfallgrowthinthesecondhalfofMarchandmid-Aprilistheresultofthemodulation.Thewet/dryphaseofCISOisaccompaniedbylow-levelconvergent(upper-leveldivergent)andcyclonic(anti-cyclonic)circulation,whichfavorsascendingmotiontodevelopoverSouthernChina.

简介：Thisstudyfocusesonthedecadalvariabilityoftropicalcyclones(TC)overtheWesternNorthPacific(WNP)andhowthesechangesarerelatedtotheMadden-JulianOscillation(MJO).ItwasdonewiththehelpoftheReal-timeMultivariateMJOindexfromtheAustralianGovernmentBureauofMeteorologyoftheCentreforAustralianWeatherandClimateResearch,TCdatafromtheJointTyphoonWarmingCenterbesttrackdatasets,anddailyandmonthlydatasetsfromtheNCEP/NCARreanalysiscenter.TheresultsshowthattheTCfrequencyintheWNPexhibitedastatisticallysignificantdecreaseduring1998-2010comparedtoduring1979-1997.ThedecreaseinTCfrequencyintheWNPmainlyoccurredduringMJOactivephases(i.e.,phases4,5,6,and7).FurtherinvestigationoftheclimatebackgroundandthepropagationdifferencesoftheMJObetween1979-1997and1998-2010wasperformed.TheLaNina-liketropicalseasurfacetemperaturecoolingcausedstrongerWalkercirculationandthusinducedunfavorableatmosphereconditionsforWNPTCgenesisincludingalow-leveleasterlyanomaly,anegativerelativevorticityanomaly,anincreaseinsea-levelpressure,andstrongerverticalwindshear.Moreover,shorteningoftheMJOcycle,declineinthedurationoftheactivephasesintheWNP,andeasterlyanomalyandshrinkageoftheconvectionareaduringMJOactivephasesmayalsopartlyexplainthedecadalvariationofTC.

简介：在下列春天和夏天的索马里人喷气(SMJ)紧张上的北方的冬季南极摆动(AAO)的teleconnection影响在这份报纸被检验。北方的冬季AAO的可变性是断然与在春天和夏天的SMJ紧张有关。分析证明在南部的高、中间的纬度的SST似乎用作连接这二个系统的一座桥。当AAO在强壮的积极阶段时，在南部的海洋上的SST在高纬度冷却并且在中间的纬度温暖，它坚持直到夏天；然而，在南部的高、中间的纬度的SST的可变性密切也被相关到有AAO-SMJ关系的连接SST可变性也是的机制讨论了的可能的SMJintensity.A。在北方的冬季的AAO通过联合的airsea在南部的高、中间的纬度生产一个SST异例模式。这个AAOrelatedSST异例模式在夏天调制本地Ferrel房间异例，在热带由地区性的哈德利房间异例列在后面。在热带的异常垂直运动然后改变landsea在通过低云盖子并且向下的可变性的热带印度洋和亚洲大陆之间的热对比表面longwave放射流动。最后，在热带印度洋之间的热对比异例和亚洲大陆改变的landseaSMJ紧张。从SST异例在南部的高、中间的纬度强迫的社区空气模型实验的结果也证实这个诊断物理过程到某程度。

简介：Theimpactofstrong(weak)intraseasonaloscillation(ISO)overSouthChinaSea(SCS)andSouthAsia(SA)insummerontheSCSandSAsummermonsoonandthesummerrainfallinEasternChinaarestudiedbyusingtheNCEP-NCARanalysisdataandtherainfalldataof160stationsinChinafrom1961to2010.Itisfoundthattheimpactsaresignificantlydifferentindifferentmonthsofsummer.ThestudyshowsthatinJuneandJulycyclonic(anticyclonic)atmosphericcirculationoverSCSandSAcorrespondstostrong(weak)ISOoverSCS.InAugust,however,strong(weak)ISOoverSCSstillcorrespondstocyclonic(anticyclonic)atmosphericcirculationoverSA.InJuneandAugustcyclonic(anticyclonic)atmosphericcirculationoverSouthAsiacorrespondstostrong(weak)ISOoverSAwhileastrong(weak)ISOcorrespondstoanticyclonic(cyclonic)atmosphericcirculationoverSAinJuly.Besides,inJunethestrong(weak)ISOoverSAcorrespondstocyclonic(anticyclonic)atmosphericcirculationoverSCS,whileinJulyandAugusttheatmosphericcirculationisinthesamephaseregardlessofwhethertheISOoverSAisstrongorweak.Theimpactsofthestrong(weak)ISOoverSCSontherainfallofeasternChinaaresimilarinJuneandJuly,whichfavorsless(more)rainfallinYangtze-HuaiheRiversbasinbutsufficient(deficient)rainfallinthesouthofYangtzeRiver.However,theimpactsarenotsoapparentinAugust.InSouthAsia,thestrong(weak)ISOinJulyresultsinless(more)rainfallinthesouthofYangtzeRiverbutsufficient(deficient)rainfallinYangtze-HuaiheRiversbasin.TheinfluenceontherainfallineasternChinainJuneandAugustisnotassignificantasinJuly.