Solar energetic proton propagation in the geomagnetic field

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dc.contributor.advisorKnudsen, David J.
dc.contributor.authorKouznetsov, Alexei
dc.date.accessioned2017-12-18T22:34:19Z
dc.date.available2017-12-18T22:34:19Z
dc.date.issued2012
dc.descriptionBibliography: p. 229-243en
dc.descriptionSome pages are in colour.en
dc.descriptionIncludes copy of copyright permission. Original copy with original Partial Copyright Licence.en
dc.description.abstractDuring solar proton events (SP Es), large fluxes of energetic protons spreading through­out the interplanetary medium (IPM) have access to the upper polar atmosphere where they play important roles in physical and chemical processes. The angular distribution of arriving solar energetic particles is a superposition of isotropic and anisotropic compo­nents. The isotropic component easily penetrates the magnetosphere forming a uniform background flux distribution inside the cut-off boundaries of the polar caps. We investi­gate the anisotropic component and the conditions that allow solar energetic protons to be focused into small spots in the polar caps, mostly near their boundaries. We examine also the dynamics of the relation between SPEs as detected through ionospheric absorption measured by a high-latitude riometer on one hand, and proton fluxes measured outside the magnetosphere by the SOHO satellite on the other. Vie find a high correlation between SOHO fluxes and absorption in some types of events (those having insignificant electron precipitation and background radio noise from the solar emission which boosts the radio signal received by the riometer causing a reduction in the measured absorption) and at some time intervals (more than ten hours after SEP onset, and within tens of hours following times of maximum flux) but not others. A probable explanation for this is that early in SPEs protons follow solar magnetic field lines and their distributions tend to be highly anisotropic, and the strong angular dependence decreases the correlation between IPM fluxes and polar cap absorption. After tens of hours the proton angular distribution becomes nearly isotropic and we find strong correlations ( correlation coefficients of up to 0.98) between the logarithm of proton integral fluxes observed at SOHO and the logarithm of polar cap absorption obtained from a NORSTAR riometer. We use these observations to construct and validate a realistic transport model that will map proton fluxes originating out ide the magnetosphere to those incident on the upper atmosphere, and vice versa. This in turn will enable riometers located outside the auroral oval to be used as a diagnostic tool to determine properties of energetic proton populations in the IPM.
dc.format.extentxvii, 243 leaves : ill. ; 30 cm.en
dc.identifier.citationKouznetsov, A. (2012). Solar energetic proton propagation in the geomagnetic field (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/4892en_US
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/4892
dc.identifier.urihttp://hdl.handle.net/1880/105893
dc.language.isoeng
dc.publisher.institutionUniversity of Calgaryen
dc.publisher.placeCalgaryen
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.titleSolar energetic proton propagation in the geomagnetic field
dc.typedoctoral thesis
thesis.degree.disciplinePhysics and Astronomy
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameDoctor of Philosophy (PhD)
ucalgary.item.requestcopytrue
ucalgary.thesis.accessionTheses Collection 58.002:Box 2111 627942981
ucalgary.thesis.notesUARCen
ucalgary.thesis.uarcreleaseyen
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