Statisticsoftheinterplanetarymagneticfieldsobservedat0.72AUand1AU

ThispaperpresentstheInterplanetaryMagneticField(IMF)observationsat0.72AUmeasuredbyVenusExpress(VEX)and1AUbyAdvancedCompositionExplorer(ACE)in2007.Thedistributionsofdailyaveragesof$B$arelognormalinbothlocations.Themultiscalestructureofthemagneticfieldfluctuationswasdescribedbystudyingtheincrementsof$B$overarangescalesfrom10minto21.3hours.AlltheProbabilityDistributionFunctions(PDFs)canbedescribedquantitativelybyTsallisdistributionfunction.Ontheeclipticplanefrom0.72AUto1AU,theentropyindexqincreaseswithdistanceoverallscales,indicatingtheintermittencyofturbulenceisgrowing.ThewidthsofthePDFsat0.72AUarelargerthanthoseat1AUatallscales,whichindicatingtheturbulenceat0.72AUismoreintensethanthatat1AU.Thishelpsusunderstandthenatureanddevelopmentofthemagneticfieldfluctuations.