Solar-wind control of plasma sheet dynamics

dc.contributorAalto-yliopistofi
dc.contributorAalto Universityen
dc.contributor.authorMyllys, M.
dc.contributor.authorKilpua, E.
dc.contributor.authorPulkkinen, T.
dc.contributor.departmentUniversity of Helsinki
dc.contributor.departmentDepartment of Radio Science and Engineering
dc.date.accessioned2016-09-23T09:31:45Z
dc.date.issued2015
dc.description.abstractThe purpose of this study is to quantify how solar-wind conditions affect the energy and plasma transport in the geomagnetic tail and its large-scale configuration. To identify the role of various effects, the magnetospheric data were sorted according to different solar-wind plasma and interplanetary magnetic field (IMF) parameters: speed, dynamic pressure, IMF north-south component, epsilon parameter, Auroral Electrojet (AE) index and IMF ultra low-frequency (ULF) fluctuation power. We study variations in the average flow speed pattern and the occurrence rate of fast flow bursts in the magnetotail during different solar-wind conditions using magnetospheric data from five Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission spacecraft and solar-wind data from NASA's OM-NIWeb. The time interval covers the years from 2008 to 2011 during the deep solar minimum between cycles 23 and 24 and the relatively quiet rising phase of cycle 24. Hence, we investigate magnetospheric processesand solar-wind-magnetospheric coupling during a relatively quiet state of the magnetosphere. We show that the occurrence rate of the fast (vertical bar V-tail vertical bar > 100 km s(-1)) sunward flows varies under different solar-wind conditions more than the occurrence of the fast tailward flows. The occurrence frequency of the fast tailward flows does not change much with the solar-wind conditions. We also note that the sign of the IMF B-Z has the most visible effect on the occurrence rate and pattern of the fast sunward flows. High-speed flow bursts are more common during the slow than fast solar-wind conditions.en
dc.description.versionPeer revieweden
dc.format.extent11
dc.format.extent845-855
dc.format.mimetypeapplication/pdf
dc.identifier.citationMyllys , M , Kilpua , E & Pulkkinen , T 2015 , ' Solar-wind control of plasma sheet dynamics ' , Annales Geophysicae , vol. 33 , no. 7 , pp. 845-855 . https://doi.org/10.5194/angeo-33-845-2015en
dc.identifier.doi10.5194/angeo-33-845-2015
dc.identifier.issn0992-7689
dc.identifier.issn1432-0576
dc.identifier.otherPURE UUID: eccfdc79-81be-478f-bb20-3ed1b1dacd83
dc.identifier.otherPURE ITEMURL: https://research.aalto.fi/en/publications/eccfdc79-81be-478f-bb20-3ed1b1dacd83
dc.identifier.otherPURE FILEURL: https://research.aalto.fi/files/6790330/angeo_33_845_2015.pdf
dc.identifier.urihttps://aaltodoc.aalto.fi/handle/123456789/22488
dc.identifier.urnURN:NBN:fi:aalto-201609234491
dc.language.isoenen
dc.relation.ispartofseriesANNALES GEOPHYSICAEen
dc.relation.ispartofseriesVolume 33, issue 7en
dc.rightsopenAccessen
dc.subject.keywordMagnetospheric physics
dc.subject.keywordplasma sheet
dc.subject.keywordINTERPLANETARY MAGNETIC-FIELD
dc.subject.keywordGEOMAGNETIC-ACTIVITY
dc.subject.keywordBULK FLOWS
dc.subject.keywordSPEED
dc.subject.keywordMAGNETOSPHERE
dc.subject.keywordEVENTS
dc.subject.keywordSUBSTORM
dc.titleSolar-wind control of plasma sheet dynamicsen
dc.typeA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessäfi
dc.type.versionpublishedVersion
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