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1、AtmosphericCirculationofClose-InExtrasolarGiantPlanets:I.Global,Barotropic,AdiabaticSimulationsJamesY-K.Cho,DepartmentofTerrestrialMagnetism,CarnegieInstitutionofWashington,5241BroadBranchRoad,N.W.,Washington,D.C.20015,USAandAstronomyUnit,SchoolofMathem
2、aticalSciences,QueenMary,UniversityofLondon,MileEndRoad,LondonE14NS,UKKristenMenou,DepartmentofAstronomy,ColumbiaUniversity,550W.120thStreet,NewYork,NY10027,USABradleyM.S.Hansen,DepartmentofPhysicsandAstronomyandInstituteforGeophysicsandPlanetaryPhysics
3、,UniversityofCalifornia,475PortolaPlaza,Box951547,LosAngeles,CA90095,USAandSaraSeagerDepartmentofTerrestrialMagnetism,CarnegieInstitutionofWashington,5241BroadBranchRoad,N.W.,Washington,D.C.20015,USAABSTRACTarXiv:astro-ph/0607338v221Oct2007Wepresentresu
4、ltsfromasetofover300pseudospectralsimulationsofat-mosphericcirculationonextrasolargiantplanetswithcircularorbits.Thesim-ulationsareofhighenoughresolution(upto341totalandsectoralmodes)toresolvesmall-scaleeddiesandwaves,requiredforreasonablephysicalaccura
5、cy.Inthiswork,wefocusontheglobalcirculationpatternthatemergesinashallow,“equivalent-barotropic”,turbulentatmosphereonbothtidallysynchronizedandunsynchronizedplanets.Afullexplorationofthelargephysicalandnumericalparameter-spaceisperformedtoidentifyrobust
6、featuresofthecirculation.Forsomevalidation,themodelisfirstappliedtoSolarSystemgiantplanets.ForextrasolargiantplanetswithphysicalparameterssimilartoHD209458b—apre-sumablysynchronizedextrasolargiantplanet,representativeinmanydynamical–2–respects—thecircula
7、tionischaracterizedbythefollowingfeatures:1)acoherentpolarvortexthatrevolvesaroundthepoleineachhemisphere;2)alownumber—typicallytwoorthree—ofslowly-varying,broadzonal(east-west)jetsthatformwhenthemaximumjetspeediscomparableto,orsomewhatstrongerthan,thos
8、eobservedontheplanetsintheSolarSystem;and,3)motion-associatedtemper-aturefield,whosedetectabilityandvariabilitydependonthestrengthofthenetheatingrateandtheglobalrootmeansquarewindspeedintheatmosphere.Inmanyways,theglobalcirculatio