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4 个结果
  • 简介:Inthispaper,theSpaceWeatherModelingFramework(SWMF)isusedtosimulatethereal-timeresponseofthemagnetospheretoasolarwindeventonJune5,1998,inwhichtheinterplanetarymagneticfieldshifteditsdirectionfromnorthtosouth.Sincemostcurrentmodelsdonottakeintoaccountconvectiveeffectsoftheinnermagnetosphere,wefirststudytheimportanceofRiceConvectionModel(RCM)intheglobalmodel.Wethenfocusonthefollowingfouraspectsofthemagnetosphere’sresponse:themagnetosphere’sdensitydistribution,thestructureofitsmagneticfieldlines,theareaofthepolarcapboundary,andthecorrespondingionosphericcurrentchange.Wefindthat(1)whentheIMFchangesfromnorthtosouthinthisevent,highmagnetosheathdensityisobservedtoflowdownstreamalongthemagnetopausewiththesolarwind;low-latitudereconnectionatdaysideoccursunderthesouthwardIMF,whilethemagneticfieldlinesinthetaillobecaudal,causedbythenightsidehighlatitudereconnection,extendintotheinterplanetaryspace.Openmagneticfieldlinesexistsimultaneouslyatbothhighandlowlatitudesatthemagnetopause;(2)theareaofthepolarcapisobviouslyincreasediftheIMFturnsfromthenorthtothesouth;thisobservationishighlyconsistentwithempiricalobservations;(3)theionosphericfieldaligncurrentinthenorthernhemisphereisstrongerthaninthesouthernhemisphereandalsoincreasesastheIMFchangesfromnorthtosouth.SWMFwiththeRiceConvectioneffectprovidesreliablemodelingofthemagnetosphericandionosphericresponsetothissolarwindvariation.

  • 标签: MAGNETOSPHERE global MHD simulation POLAR cap
  • 简介:WepresentpreliminaryresultsofanewglobalMagnetohydrodynamics(MHD)simulationmodeloftheJovianmagnetosphere.ThemodelincorporatesmassloadingfromJupiter'ssatelliteIo,theplanet'sfastcorotation,andelectrostaticcouplingbetweenitsmagnetosphereandionosphere(M-Icoupling).ThebasicconfigurationoftheJovianmagnetosphereincludingtheequatorialplasmaflowpattern,thecorotationenforcementcurrentsystem,andthefieldalignedcurrents(FACs)intheionospherearepresentedunderanantiparallelinterplanetarymagneticfield(IMF)condition.Thesimulationmodelresultsforequatorialdensityandpressureprofilesareconsistentwithresultsfromdata-basedempiricalmodels.ItisalsofoundthattherearesimilaritiesbetweentheFACsdistributionintheionosphereandtheobservedaurorafeatures,showingthepotentialapplicationofthesimpleionosphericmodeltothecomplicatedM-Icoupling.ThismodelwillhelpdeepenourunderstandingoftheglobaldynamicsoftheJovianmagnetosphere.

  • 标签: JUPITER MAGNETOSPHERE magnetohydrodynamic(MHD)simulation
  • 简介:Whistler-modechoruswavesareregardedasanimportantaccelerationmechanismcontributingtotheformationofrelativisticandultra-relativisticelectronsintheJovianradiationbelts.QuantitativedeterminationofthechoruswavedrivenelectronscatteringeffectintheJovianmagnetosphererequiresdetailedinformationofbothambientmagneticfieldandplasmadensityandwavespectralproperty,whichhowevercannotbealwaysreadilyacquiredfromobservationsofexistedmissionstoJupiter.WethereforeperformacomprehensiveanalysisofthesensitivityofchorusinducedelectronscatteringratestoambientmagnetosphericandwaveparametersintheJovianradiationbeltstoelaboratetowhichextentthediffusioncoefficientsdependonanumberofkeyinputparameters.Itisfoundthatquasi-linearelectronscatteringratesbychoruscanbestronglyaffectedbytheambientmagneticfieldintensity,thewavelatitudinalcoverage,andthepeakfrequencyandbandwidthofthewavespectraldistributionintheJovianmagnetosphere,whiletheyonlyrelyslightlyonthebackgroundplasmadensityprofileandthepeakwavenormalangle,especiallywhenthewaveemissionsareconfinedatlowerlatitudes.Giventhechoruswaveamplitude,chorusinducedelectronscatteringratesstronglydependonJovianL-shelltoexhibitatendencyapproximatelyproportionaltoLJ3.OurcomprehensiveanalysisexplicitlydemonstratestheimportanceofreliableinformationofboththeambientmagnetosphericstateandwavedistributionpropertytounderstandingthedynamicelectronevolutionintheJovianradiationbeltsandthereforehasimplicationsforfuturemissionplanningtoexploretheextremeparticleradiationenvironmentofJupiteranditssatellites.

  • 标签: Jovian radiation BELTS whistler-mode CHORUS RESONANT