Variations of auroral hydrogen emission near substorm onset
The results of coordinated optical ground-based observations of the auroral substorm on 26 March 2004 in the Kola Peninsula are described. Imaging spectrograph data with high spectral and temporal resolution recorded the Doppler profile of the Hα hydrogen emission; this allows us to estimate the ave...
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ftdoajarticles:oai:doaj.org/article:438eb54618bf4991919a811dd7ef058b 2023-05-15T17:05:02+02:00 Variations of auroral hydrogen emission near substorm onset L. P. Borovkov B. V. Kozelov L. S. Yevlashin S. A. Chernouss 2005-07-01T00:00:00Z https://doi.org/10.5194/angeo-23-1623-2005 https://doaj.org/article/438eb54618bf4991919a811dd7ef058b EN eng Copernicus Publications https://www.ann-geophys.net/23/1623/2005/angeo-23-1623-2005.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-23-1623-2005 0992-7689 1432-0576 https://doaj.org/article/438eb54618bf4991919a811dd7ef058b Annales Geophysicae, Vol 23, Pp 1623-1635 (2005) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2005 ftdoajarticles https://doi.org/10.5194/angeo-23-1623-2005 2022-12-31T15:46:43Z The results of coordinated optical ground-based observations of the auroral substorm on 26 March 2004 in the Kola Peninsula are described. Imaging spectrograph data with high spectral and temporal resolution recorded the Doppler profile of the Hα hydrogen emission; this allows us to estimate the average energy of precipitating protons and the emission intensity of the hydrogen Balmer line. Two different populations of precipitating protons were observed during an auroral substorm. The first of these is associated with a diffuse hydrogen emission that is usually observed in the evening sector of the auroral oval and located equatorward of the discrete electron arcs associated with substorm onset. The average energy of the protons during this precipitation was ~20–35 keV, and the energy flux was ~3x10 –4 Joule/m 2 s. The second proton population was observed 1–2min after the breakup during 4–5min of the expansion phase of substorm into the zone of bright, discrete auroral structures (N-S arcs). The average energy of the protons in this population was ~60 keV, and the energy flux was ~2.2x10 –3 Joule/m 2 s. The observed spatial structure of hydrogen emission is additional evidence of the higher energy of precipitated protons in the second population, relative to the protons in the diffuse aurora. We believe that the most probable mechanism of precipitation of the second population protons was pitch-angle scattering of particles due to non-adiabatic motion in the region of local dipolarization near the equatorial plane. Keywords. Auroral ionosphere; Particle precipitation; Storms and substorms Article in Journal/Newspaper kola peninsula Directory of Open Access Journals: DOAJ Articles Kola Peninsula Annales Geophysicae 23 5 1623 1635 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
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English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 L. P. Borovkov B. V. Kozelov L. S. Yevlashin S. A. Chernouss Variations of auroral hydrogen emission near substorm onset |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
The results of coordinated optical ground-based observations of the auroral substorm on 26 March 2004 in the Kola Peninsula are described. Imaging spectrograph data with high spectral and temporal resolution recorded the Doppler profile of the Hα hydrogen emission; this allows us to estimate the average energy of precipitating protons and the emission intensity of the hydrogen Balmer line. Two different populations of precipitating protons were observed during an auroral substorm. The first of these is associated with a diffuse hydrogen emission that is usually observed in the evening sector of the auroral oval and located equatorward of the discrete electron arcs associated with substorm onset. The average energy of the protons during this precipitation was ~20–35 keV, and the energy flux was ~3x10 –4 Joule/m 2 s. The second proton population was observed 1–2min after the breakup during 4–5min of the expansion phase of substorm into the zone of bright, discrete auroral structures (N-S arcs). The average energy of the protons in this population was ~60 keV, and the energy flux was ~2.2x10 –3 Joule/m 2 s. The observed spatial structure of hydrogen emission is additional evidence of the higher energy of precipitated protons in the second population, relative to the protons in the diffuse aurora. We believe that the most probable mechanism of precipitation of the second population protons was pitch-angle scattering of particles due to non-adiabatic motion in the region of local dipolarization near the equatorial plane. Keywords. Auroral ionosphere; Particle precipitation; Storms and substorms |
format |
Article in Journal/Newspaper |
author |
L. P. Borovkov B. V. Kozelov L. S. Yevlashin S. A. Chernouss |
author_facet |
L. P. Borovkov B. V. Kozelov L. S. Yevlashin S. A. Chernouss |
author_sort |
L. P. Borovkov |
title |
Variations of auroral hydrogen emission near substorm onset |
title_short |
Variations of auroral hydrogen emission near substorm onset |
title_full |
Variations of auroral hydrogen emission near substorm onset |
title_fullStr |
Variations of auroral hydrogen emission near substorm onset |
title_full_unstemmed |
Variations of auroral hydrogen emission near substorm onset |
title_sort |
variations of auroral hydrogen emission near substorm onset |
publisher |
Copernicus Publications |
publishDate |
2005 |
url |
https://doi.org/10.5194/angeo-23-1623-2005 https://doaj.org/article/438eb54618bf4991919a811dd7ef058b |
geographic |
Kola Peninsula |
geographic_facet |
Kola Peninsula |
genre |
kola peninsula |
genre_facet |
kola peninsula |
op_source |
Annales Geophysicae, Vol 23, Pp 1623-1635 (2005) |
op_relation |
https://www.ann-geophys.net/23/1623/2005/angeo-23-1623-2005.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-23-1623-2005 0992-7689 1432-0576 https://doaj.org/article/438eb54618bf4991919a811dd7ef058b |
op_doi |
https://doi.org/10.5194/angeo-23-1623-2005 |
container_title |
Annales Geophysicae |
container_volume |
23 |
container_issue |
5 |
container_start_page |
1623 |
op_container_end_page |
1635 |
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1766059410853986304 |