影響西南低渦發(fā)展因子的研究.pdf

1、南京信息工程大學碩士學位論文影響西南低渦發(fā)展因子的研究姓名：尹君申請學位級別：碩士專業(yè)：氣象學指導教師：閔錦忠20100401AbstractHereweimprovethestatisticalmethodofsouthwestvortexbyusingtheNCEP／NCARreanalysisdataofthegeopotentialheightandwindfor19512005，toseparateindependentpro

2、cessofsouthwestvortexbuildinganddevelopingWealsocounttimesofvortexdevelopingandmeiIlterannualchangeofbuildinganddevelopingIn55years，statistics01“1developingvortexappearascent，anddevelopingproportionisalsiseTtomeasurethat

3、vortexisdevelopingornot，astandardissetupbyusingnonthermalwindvorticity12hoursbeforevortexbuilding，positivenonthermalwindvorticityisgreaterIfnonthelmalwindvorticityisgreaterthan378，vortexwilldevelopIfnonthermalwindvortici

4、tyislessthan118，vortexwillperishgraduallyBycontrastofdevelopingvortexandperishingvortex，wefoundthattherearequitedi岱erencesinflowfield，geopotentialheight，vorticityadvectionfield，divergencefieldandSOOnFirstly，whenmereisadi

5、sturbanceabovevortexinmiddletroposphere，ifvortexcenterisin矗ontofdisturbancea11dinsouthwesterthepositivevorticitywillurgevortextodevelop，ifcenterisbehinddisturbanceandinnorthwesterthevortexwillperishgraduallySecondlywhile

6、southwestvortexisconvergenceinmiddleandlowertroposphereofatITlosphere，itmustisdivergenceinuppertroposphere，whichintensityisgreater，otherwisevortexwillperishstepbystepThirdlv’whenVcInexisinfrontofuppertroughandtroughdeeps

7、，bothpositivevorticityadvectionaIldupdrafIarebeneficialtothedevelopmentofvortexIfvortexisbehinduppertroughorbelowupperridge，vortexwillperishInaddition，adevelopingexampleisanalyzedtofinditsstructurefeatureinthestageofbuil