Outer radiation belt and inner magnetospheric response to sheath regions of coronal mass ejections : a statistical analysis

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dc.contributor.author Kalliokoski, Milla M. H.
dc.contributor.author Kilpua, Emilia K. J.
dc.contributor.author Osmane, Adnane
dc.contributor.author Turner, Drew L.
dc.contributor.author Jaynes, Allison N.
dc.contributor.author Turc, Lucile
dc.contributor.author George, Harriet
dc.contributor.author Palmroth, Minna
dc.date.accessioned 2020-08-18T06:58:02Z
dc.date.available 2020-08-18T06:58:02Z
dc.date.issued 2020-06-09
dc.identifier.citation Kalliokoski , M M H , Kilpua , E K J , Osmane , A , Turner , D L , Jaynes , A N , Turc , L , George , H & Palmroth , M 2020 , ' Outer radiation belt and inner magnetospheric response to sheath regions of coronal mass ejections : a statistical analysis ' , Annales Geophysicae , vol. 38 , no. 3 , pp. 683-701 . https://doi.org/10.5194/angeo-38-683-2020
dc.identifier.other PURE: 142513215
dc.identifier.other PURE UUID: c59247d6-5e42-46b6-b29b-cf83457e52d9
dc.identifier.other WOS: 000541457900001
dc.identifier.other ORCID: /0000-0003-4857-1227/work/79181303
dc.identifier.other ORCID: /0000-0002-4489-8073/work/79181306
dc.identifier.other ORCID: /0000-0002-7576-3251/work/79183711
dc.identifier.other ORCID: /0000-0002-6445-5595/work/79183863
dc.identifier.uri http://hdl.handle.net/10138/318375
dc.description.abstract The energetic electron content in the Van Allen radiation belts surrounding the Earth can vary dramatically at several timescales, and these strong electron fluxes present a hazard for spacecraft traversing the belts. The belt response to solar wind driving is, however, largely unpredictable, and the direct response to specific large-scale heliospheric structures has not been considered previously. We investigate the immediate response of electron fluxes in the outer belt that are driven by sheath regions preceding interplanetary coronal mass ejections and the associated wave activity in the inner magnetosphere. We consider the events recorded from 2012 to 2018 in the Van Allen Probes era to utilise the energy- and radial-distance-resolved electron flux observations of the twin spacecraft mission. We perform a statistical study of the events by using the superposed epoch analysis in which the sheaths are superposed separately from the ejecta and resampled to the same average duration. Our results show that the wave power of ultra-low frequency Pc5 and electromagnetic ion cyclotron waves, as measured by a Geostationary Operational Environmental Satellite (GOES), is higher during the sheath than during the ejecta. However, the level of chorus wave power, as measured by the Van Allen Probes, remains approximately the same due to similar substorm activity during the sheath and ejecta. Electron flux enhancements are common at low energies (<1 MeV) throughout the outer belt (L = 3-6), whereas depletion predominantly occurs at high energies for high radial distances (L > 4). It is distinctive that the depletion extends to lower energies at larger distances. We suggest that this L-shell and energy-dependent depletion results from the magnetopause shadowing that dominates the losses at large distances, while the wave-particle interactions dominate closer to the Earth. We also show that non-geoeffective sheaths cause significant changes in the outer belt electron fluxes. en
dc.format.extent 19
dc.language.iso eng
dc.relation.ispartof Annales Geophysicae
dc.rights cc_by
dc.rights.uri info:eu-repo/semantics/openAccess
dc.subject DRIVEN
dc.subject DIFFUSION
dc.subject DYNAMICS
dc.subject 115 Astronomy, Space science
dc.title Outer radiation belt and inner magnetospheric response to sheath regions of coronal mass ejections : a statistical analysis en
dc.type Article
dc.contributor.organization Space Physics Research Group
dc.contributor.organization Particle Physics and Astrophysics
dc.contributor.organization Department of Physics
dc.description.reviewstatus Peer reviewed
dc.relation.doi https://doi.org/10.5194/angeo-38-683-2020
dc.relation.issn 0992-7689
dc.rights.accesslevel openAccess
dc.type.version publishedVersion

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