Estimation of the characteristic energy of electron precipitation
Data from simultaneous observations (on 13 February 1996, 9 November 1998, and 12 February 1999) with the IRIS, DASI and EISCAT systems are employed in the study of the energy distribution of the electron precipitation during substorm activity. The estimation of the characteristic energy of the elec...
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ftdoajarticles:oai:doaj.org/article:0d995d0cacc14884a8fe1911a09930ec 2023-05-15T16:04:36+02:00 Estimation of the characteristic energy of electron precipitation C. F. del Pozo M. J. Kosch F. Honary 2002-09-01T00:00:00Z https://doi.org/10.5194/angeo-20-1349-2002 https://doaj.org/article/0d995d0cacc14884a8fe1911a09930ec EN eng Copernicus Publications https://www.ann-geophys.net/20/1349/2002/angeo-20-1349-2002.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-20-1349-2002 0992-7689 1432-0576 https://doaj.org/article/0d995d0cacc14884a8fe1911a09930ec Annales Geophysicae, Vol 20, Pp 1349-1359 (2002) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2002 ftdoajarticles https://doi.org/10.5194/angeo-20-1349-2002 2022-12-31T14:31:04Z Data from simultaneous observations (on 13 February 1996, 9 November 1998, and 12 February 1999) with the IRIS, DASI and EISCAT systems are employed in the study of the energy distribution of the electron precipitation during substorm activity. The estimation of the characteristic energy of the electron precipitation over the common field of view of IRIS and DASI is discussed. In particular, we look closely at the physical basis of the correspondence between the characteristic energy, the flux-averaged energy, as defined below, and the logarithm of the ratio of the green-light intensity to the square of absorption. This study expands and corrects results presented in the paper by Kosch et al. (2001). It is noticed, moreover, that acceleration associated with diffusion processes in the magnetosphere long before precipitation may be controlling the shape of the energy spectrum. We propose and test a "mixed" distribution for the energy-flux spectrum, exponential at the lower energies and Maxwellian or modified power-law at the higher energies, with a threshold energy separating these two regimes. The energy-flux spectrum at Tromsø, in the 1–320 keV range, is derived from EISCAT electron density profiles in the 70–140 km altitude range and is applied in the "calibration" of the optical intensity and absorption distributions, in order to extrapolate the flux and characteristic energy maps. Key words. Ionosphere (auroral ionosphere; particle precipitation; particle acceleration) Article in Journal/Newspaper EISCAT Tromsø Directory of Open Access Journals: DOAJ Articles Tromsø Annales Geophysicae 20 9 1349 1359 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 C. F. del Pozo M. J. Kosch F. Honary Estimation of the characteristic energy of electron precipitation |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
Data from simultaneous observations (on 13 February 1996, 9 November 1998, and 12 February 1999) with the IRIS, DASI and EISCAT systems are employed in the study of the energy distribution of the electron precipitation during substorm activity. The estimation of the characteristic energy of the electron precipitation over the common field of view of IRIS and DASI is discussed. In particular, we look closely at the physical basis of the correspondence between the characteristic energy, the flux-averaged energy, as defined below, and the logarithm of the ratio of the green-light intensity to the square of absorption. This study expands and corrects results presented in the paper by Kosch et al. (2001). It is noticed, moreover, that acceleration associated with diffusion processes in the magnetosphere long before precipitation may be controlling the shape of the energy spectrum. We propose and test a "mixed" distribution for the energy-flux spectrum, exponential at the lower energies and Maxwellian or modified power-law at the higher energies, with a threshold energy separating these two regimes. The energy-flux spectrum at Tromsø, in the 1–320 keV range, is derived from EISCAT electron density profiles in the 70–140 km altitude range and is applied in the "calibration" of the optical intensity and absorption distributions, in order to extrapolate the flux and characteristic energy maps. Key words. Ionosphere (auroral ionosphere; particle precipitation; particle acceleration) |
format |
Article in Journal/Newspaper |
author |
C. F. del Pozo M. J. Kosch F. Honary |
author_facet |
C. F. del Pozo M. J. Kosch F. Honary |
author_sort |
C. F. del Pozo |
title |
Estimation of the characteristic energy of electron precipitation |
title_short |
Estimation of the characteristic energy of electron precipitation |
title_full |
Estimation of the characteristic energy of electron precipitation |
title_fullStr |
Estimation of the characteristic energy of electron precipitation |
title_full_unstemmed |
Estimation of the characteristic energy of electron precipitation |
title_sort |
estimation of the characteristic energy of electron precipitation |
publisher |
Copernicus Publications |
publishDate |
2002 |
url |
https://doi.org/10.5194/angeo-20-1349-2002 https://doaj.org/article/0d995d0cacc14884a8fe1911a09930ec |
geographic |
Tromsø |
geographic_facet |
Tromsø |
genre |
EISCAT Tromsø |
genre_facet |
EISCAT Tromsø |
op_source |
Annales Geophysicae, Vol 20, Pp 1349-1359 (2002) |
op_relation |
https://www.ann-geophys.net/20/1349/2002/angeo-20-1349-2002.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-20-1349-2002 0992-7689 1432-0576 https://doaj.org/article/0d995d0cacc14884a8fe1911a09930ec |
op_doi |
https://doi.org/10.5194/angeo-20-1349-2002 |
container_title |
Annales Geophysicae |
container_volume |
20 |
container_issue |
9 |
container_start_page |
1349 |
op_container_end_page |
1359 |
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1766400195235414016 |