Variations of auroral hydrogen emission near substorm onset
Abstract. 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 estima...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.210.2398 2023-05-15T17:05:01+02:00 Variations of auroral hydrogen emission near substorm onset L. P. Borovkov B. V. Kozelov L. S. Yevlashin S. A. Chernouss The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.210.2398 http://www.ann-geophys.net/23/1623/2005/angeo-23-1623-2005.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.210.2398 http://www.ann-geophys.net/23/1623/2005/angeo-23-1623-2005.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.ann-geophys.net/23/1623/2005/angeo-23-1623-2005.pdf Particle precipitation text ftciteseerx 2016-01-07T17:49:12Z Abstract. 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 ∼3×10−4Joule/m2s. The second proton population was observed 1–2 min after the breakup during 4–5 min 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 ∼2.2×10−3Joule/m2s. 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. Text kola peninsula Unknown Kola Peninsula |
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English |
topic |
Particle precipitation |
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Particle precipitation L. P. Borovkov B. V. Kozelov L. S. Yevlashin S. A. Chernouss Variations of auroral hydrogen emission near substorm onset |
topic_facet |
Particle precipitation |
description |
Abstract. 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 ∼3×10−4Joule/m2s. The second proton population was observed 1–2 min after the breakup during 4–5 min 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 ∼2.2×10−3Joule/m2s. 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. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
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 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.210.2398 http://www.ann-geophys.net/23/1623/2005/angeo-23-1623-2005.pdf |
geographic |
Kola Peninsula |
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Kola Peninsula |
genre |
kola peninsula |
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kola peninsula |
op_source |
http://www.ann-geophys.net/23/1623/2005/angeo-23-1623-2005.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.210.2398 http://www.ann-geophys.net/23/1623/2005/angeo-23-1623-2005.pdf |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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