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The Largest Electron Differential Energy Flux Observed at Mars by the Mars Express Spacecraft, 2004–2016

The goal of this paper is to understand the processes by which solar wind electrons are energized in the Martian magnetosphere and how this compares to processes at Venus and Earth. Each is unique in the source of its magnetic field topology and how this influences electron energization. To achieve...

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Detalles Bibliográficos
Autores principales: Frahm, R. A., Winningham, J. D., Coates, A. J., Gérard, J.‐C., Holmström, M., Barabash, S.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6473521/
https://www.ncbi.nlm.nih.gov/pubmed/31032167
http://dx.doi.org/10.1029/2018JA025311
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author Frahm, R. A.
Winningham, J. D.
Coates, A. J.
Gérard, J.‐C.
Holmström, M.
Barabash, S.
author_facet Frahm, R. A.
Winningham, J. D.
Coates, A. J.
Gérard, J.‐C.
Holmström, M.
Barabash, S.
author_sort Frahm, R. A.
collection PubMed
description The goal of this paper is to understand the processes by which solar wind electrons are energized in the Martian magnetosphere and how this compares to processes at Venus and Earth. Each is unique in the source of its magnetic field topology and how this influences electron energization. To achieve this goal, 24 million spectra spanning 13 years have been examined using the electron spectrometer from the Mars Express spacecraft between about 12,000 km and about 250 km altitude, and from all latitudes and local times. The top 10 largest differential energy flux at energies above the differential energy flux peak have been found: seven spectra from the magnetosheath near noon, three from the dark tail (the largest two from the middle and ionospheric edge of the magnetosheath). Spectral comparisons show a decade range in the peak of the electron distributions; however, all distributions show a similar energy maximum dictated by solar wind/planet interaction. Similarly derived, the largest Venus spectrum occurred near the magnetosheath bow shock and had the same shape as the most intense Mars inner magnetosheath spectrum. The Mars and Venus dayside spectra compared to the Mars nightside spectrum that included an enhanced optical signal attributed to discrete “auroral” precipitation show a similar shape. These spectra are also compared to a selected auroral zone electron spectra from the Earth. The Mars and Venus results suggest that there is no more energy needed to generate electrons forming the nightside precipitation than is gained during the solar wind/planet interaction.
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spelling pubmed-64735212019-04-24 The Largest Electron Differential Energy Flux Observed at Mars by the Mars Express Spacecraft, 2004–2016 Frahm, R. A. Winningham, J. D. Coates, A. J. Gérard, J.‐C. Holmström, M. Barabash, S. J Geophys Res Space Phys Research Articles The goal of this paper is to understand the processes by which solar wind electrons are energized in the Martian magnetosphere and how this compares to processes at Venus and Earth. Each is unique in the source of its magnetic field topology and how this influences electron energization. To achieve this goal, 24 million spectra spanning 13 years have been examined using the electron spectrometer from the Mars Express spacecraft between about 12,000 km and about 250 km altitude, and from all latitudes and local times. The top 10 largest differential energy flux at energies above the differential energy flux peak have been found: seven spectra from the magnetosheath near noon, three from the dark tail (the largest two from the middle and ionospheric edge of the magnetosheath). Spectral comparisons show a decade range in the peak of the electron distributions; however, all distributions show a similar energy maximum dictated by solar wind/planet interaction. Similarly derived, the largest Venus spectrum occurred near the magnetosheath bow shock and had the same shape as the most intense Mars inner magnetosheath spectrum. The Mars and Venus dayside spectra compared to the Mars nightside spectrum that included an enhanced optical signal attributed to discrete “auroral” precipitation show a similar shape. These spectra are also compared to a selected auroral zone electron spectra from the Earth. The Mars and Venus results suggest that there is no more energy needed to generate electrons forming the nightside precipitation than is gained during the solar wind/planet interaction. John Wiley and Sons Inc. 2018-08-22 2018-08 /pmc/articles/PMC6473521/ /pubmed/31032167 http://dx.doi.org/10.1029/2018JA025311 Text en ©2018. The Authors. This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Articles
Frahm, R. A.
Winningham, J. D.
Coates, A. J.
Gérard, J.‐C.
Holmström, M.
Barabash, S.
The Largest Electron Differential Energy Flux Observed at Mars by the Mars Express Spacecraft, 2004–2016
title The Largest Electron Differential Energy Flux Observed at Mars by the Mars Express Spacecraft, 2004–2016
title_full The Largest Electron Differential Energy Flux Observed at Mars by the Mars Express Spacecraft, 2004–2016
title_fullStr The Largest Electron Differential Energy Flux Observed at Mars by the Mars Express Spacecraft, 2004–2016
title_full_unstemmed The Largest Electron Differential Energy Flux Observed at Mars by the Mars Express Spacecraft, 2004–2016
title_short The Largest Electron Differential Energy Flux Observed at Mars by the Mars Express Spacecraft, 2004–2016
title_sort largest electron differential energy flux observed at mars by the mars express spacecraft, 2004–2016
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6473521/
https://www.ncbi.nlm.nih.gov/pubmed/31032167
http://dx.doi.org/10.1029/2018JA025311
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