On the fine structure of medium energy electron fluxes in the auroral zone and related effects in the ionospheric D-region
This study is based on measurements of trapped and precipitated electrons of energy >30 keV and >100 keV observed by polar orbiting environmental satellites during overpasses of the imaging riometer at Kilpisjärvi, Finland. The satellites are in sun-synchronous orbits of about 850 km altitude,...
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ftdoajarticles:oai:doaj.org/article:17dc3085e4104cb0bfd9b309f671281d 2023-05-15T17:03:43+02:00 On the fine structure of medium energy electron fluxes in the auroral zone and related effects in the ionospheric D-region J. K. Hargreaves M. J. Birch D. S. Evans 2010-05-01T00:00:00Z https://doi.org/10.5194/angeo-28-1107-2010 https://doaj.org/article/17dc3085e4104cb0bfd9b309f671281d EN eng Copernicus Publications https://www.ann-geophys.net/28/1107/2010/angeo-28-1107-2010.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-28-1107-2010 0992-7689 1432-0576 https://doaj.org/article/17dc3085e4104cb0bfd9b309f671281d Annales Geophysicae, Vol 28, Pp 1107-1120 (2010) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2010 ftdoajarticles https://doi.org/10.5194/angeo-28-1107-2010 2022-12-31T15:54:47Z This study is based on measurements of trapped and precipitated electrons of energy >30 keV and >100 keV observed by polar orbiting environmental satellites during overpasses of the imaging riometer at Kilpisjärvi, Finland. The satellites are in sun-synchronous orbits of about 850 km altitude, recording the electron fluxes at 2-s time resolution. The riometer measures the radiowave absorption at 38.2 MHz, showing the spatial pattern within a 240 km field of view. The analysis has focussed on two areas. Having found a close correlation between the radiowave absorption and the medium-energy electron fluxes during satellite overpasses, empirical relationships are derived, enabling one quantity to be predicted from the other for three sectors of local time. It is shown that small-scale variations observed during a pass are essentially spatial rather than temporal. Other properties, such as the spectra and the relation between precipitated and trapped components, are also considered in the light of the theory of pitch angle scattering by VLF waves. It is found that the properties and behaviour depend strongly on the time of day. In the noon sector, the precipitated and trapped fluxes are highly correlated through a square law relationship. Article in Journal/Newspaper Kilpisjärvi Directory of Open Access Journals: DOAJ Articles Kilpisjärvi ENVELOPE(20.767,20.767,69.034,69.034) Annales Geophysicae 28 5 1107 1120 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
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 J. K. Hargreaves M. J. Birch D. S. Evans On the fine structure of medium energy electron fluxes in the auroral zone and related effects in the ionospheric D-region |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
This study is based on measurements of trapped and precipitated electrons of energy >30 keV and >100 keV observed by polar orbiting environmental satellites during overpasses of the imaging riometer at Kilpisjärvi, Finland. The satellites are in sun-synchronous orbits of about 850 km altitude, recording the electron fluxes at 2-s time resolution. The riometer measures the radiowave absorption at 38.2 MHz, showing the spatial pattern within a 240 km field of view. The analysis has focussed on two areas. Having found a close correlation between the radiowave absorption and the medium-energy electron fluxes during satellite overpasses, empirical relationships are derived, enabling one quantity to be predicted from the other for three sectors of local time. It is shown that small-scale variations observed during a pass are essentially spatial rather than temporal. Other properties, such as the spectra and the relation between precipitated and trapped components, are also considered in the light of the theory of pitch angle scattering by VLF waves. It is found that the properties and behaviour depend strongly on the time of day. In the noon sector, the precipitated and trapped fluxes are highly correlated through a square law relationship. |
format |
Article in Journal/Newspaper |
author |
J. K. Hargreaves M. J. Birch D. S. Evans |
author_facet |
J. K. Hargreaves M. J. Birch D. S. Evans |
author_sort |
J. K. Hargreaves |
title |
On the fine structure of medium energy electron fluxes in the auroral zone and related effects in the ionospheric D-region |
title_short |
On the fine structure of medium energy electron fluxes in the auroral zone and related effects in the ionospheric D-region |
title_full |
On the fine structure of medium energy electron fluxes in the auroral zone and related effects in the ionospheric D-region |
title_fullStr |
On the fine structure of medium energy electron fluxes in the auroral zone and related effects in the ionospheric D-region |
title_full_unstemmed |
On the fine structure of medium energy electron fluxes in the auroral zone and related effects in the ionospheric D-region |
title_sort |
on the fine structure of medium energy electron fluxes in the auroral zone and related effects in the ionospheric d-region |
publisher |
Copernicus Publications |
publishDate |
2010 |
url |
https://doi.org/10.5194/angeo-28-1107-2010 https://doaj.org/article/17dc3085e4104cb0bfd9b309f671281d |
long_lat |
ENVELOPE(20.767,20.767,69.034,69.034) |
geographic |
Kilpisjärvi |
geographic_facet |
Kilpisjärvi |
genre |
Kilpisjärvi |
genre_facet |
Kilpisjärvi |
op_source |
Annales Geophysicae, Vol 28, Pp 1107-1120 (2010) |
op_relation |
https://www.ann-geophys.net/28/1107/2010/angeo-28-1107-2010.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-28-1107-2010 0992-7689 1432-0576 https://doaj.org/article/17dc3085e4104cb0bfd9b309f671281d |
op_doi |
https://doi.org/10.5194/angeo-28-1107-2010 |
container_title |
Annales Geophysicae |
container_volume |
28 |
container_issue |
5 |
container_start_page |
1107 |
op_container_end_page |
1120 |
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