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.
简介:Thequantitativeinterpretationofgravityanomaliesduetoshallowstructuresneedsseparationbetweenlongwavelengthanomalies(regionalanomalies)andshortwavelengthanomalies(residualanomalies).Theregional-residualfieldseparationcanbecarriedoutusingthepolynomialmethod.Inthiscase,theso-calledregionalfieldofordernistreatedasapolynomialofdegreen.Thepresentstudyshowsthatthedegreenmustvarybetweenasmallestvaluenminandamaximumvaluenmax.Thisarticlepresentsamethodtoprocessgravitydatathatallowsdeterminationofnminandnmaxforagivenstudyarea.WeapplythemethodtogravitydataoftheSouth-WestCameroonzone.Inthischosenstudyarea,wefindthatregionalanomalymapsofordersrangingfrom1to9andresidualanomalymapsofordersrangingfrom1to8canbeusedforsuitableinterpretation.Theanalysesshowthatonemayneedresidualanomalymapsofseveralorderstoperformsatisfactoryquantitativeinterpretationofthedifferentintrusivebodiesfoundinagivenarea.