The statistical dependence of auroral absorption on geomagnetic and solar wind parameters
Data from the Imaging Riometer for Ionospheric Studies (IRIS) at Kilpisjärvi, Finland, have been compiled to form statistics of auroral absorption based on seven years of observations. In a previous study a linear relationship between the logarithm of the absorption and the K p index provided a link...
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ftdoajarticles:oai:doaj.org/article:db02aa24136e450a8c8234438b4dbb48 2023-05-15T17:03:44+02:00 The statistical dependence of auroral absorption on geomagnetic and solar wind parameters A. J. Kavanagh M. J. Kosch F. Honary A. Senior S. R. Marple E. E. Woodfield I. W. McCrea 2004-03-01T00:00:00Z https://doi.org/10.5194/angeo-22-877-2004 https://doaj.org/article/db02aa24136e450a8c8234438b4dbb48 EN eng Copernicus Publications https://www.ann-geophys.net/22/877/2004/angeo-22-877-2004.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-22-877-2004 0992-7689 1432-0576 https://doaj.org/article/db02aa24136e450a8c8234438b4dbb48 Annales Geophysicae, Vol 22, Pp 877-887 (2004) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2004 ftdoajarticles https://doi.org/10.5194/angeo-22-877-2004 2022-12-31T01:49:45Z Data from the Imaging Riometer for Ionospheric Studies (IRIS) at Kilpisjärvi, Finland, have been compiled to form statistics of auroral absorption based on seven years of observations. In a previous study a linear relationship between the logarithm of the absorption and the K p index provided a link between the observations of precipitation with the level of geomagnetic activity. A better fit to the absorption data is found in the form of a quadratic in K p for eight magnetic local time sectors. Past statistical investigations of absorption have hinted at the possibility of using the solar wind velocity as a proxy for the auroral absorption, although the lack of available satellite data made such an investigation difficult. Here we employ data from the solar wind monitors, WIND and ACE, and derive a linear relationship between the solar wind velocity and the cosmic noise absorption at IRIS for the same eight magnetic local time sectors. As far as the authors are aware this is the first time that in situ measurements of the solar wind velocity have been used to create a direct link with absorption on a statistical basis. The results are promising although, it is clear that some other factor is necessary in providing reliable absorption predictions. Due to the substorm related nature of auroral absorption, this is likely formed by the recent time history of the geomagnetic activity, or by some other indicator of the energy stored within the magnetotail. For example, a dependence on the southward IMF (interplanetary magnetic field) is demonstrated with absorption increasing with successive decreases in B z a northward IMF appears to have little effect and neither does the eastward component, B y . Key words. Magnetospheric physics (energetic particles, precipitating; solar wind-magnetosphere interactions) – Ionosphere (modeling and forecasting) Article in Journal/Newspaper Kilpisjärvi Directory of Open Access Journals: DOAJ Articles Kilpisjärvi ENVELOPE(20.767,20.767,69.034,69.034) Annales Geophysicae 22 3 877 887 |
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Open Polar |
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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 A. J. Kavanagh M. J. Kosch F. Honary A. Senior S. R. Marple E. E. Woodfield I. W. McCrea The statistical dependence of auroral absorption on geomagnetic and solar wind parameters |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
Data from the Imaging Riometer for Ionospheric Studies (IRIS) at Kilpisjärvi, Finland, have been compiled to form statistics of auroral absorption based on seven years of observations. In a previous study a linear relationship between the logarithm of the absorption and the K p index provided a link between the observations of precipitation with the level of geomagnetic activity. A better fit to the absorption data is found in the form of a quadratic in K p for eight magnetic local time sectors. Past statistical investigations of absorption have hinted at the possibility of using the solar wind velocity as a proxy for the auroral absorption, although the lack of available satellite data made such an investigation difficult. Here we employ data from the solar wind monitors, WIND and ACE, and derive a linear relationship between the solar wind velocity and the cosmic noise absorption at IRIS for the same eight magnetic local time sectors. As far as the authors are aware this is the first time that in situ measurements of the solar wind velocity have been used to create a direct link with absorption on a statistical basis. The results are promising although, it is clear that some other factor is necessary in providing reliable absorption predictions. Due to the substorm related nature of auroral absorption, this is likely formed by the recent time history of the geomagnetic activity, or by some other indicator of the energy stored within the magnetotail. For example, a dependence on the southward IMF (interplanetary magnetic field) is demonstrated with absorption increasing with successive decreases in B z a northward IMF appears to have little effect and neither does the eastward component, B y . Key words. Magnetospheric physics (energetic particles, precipitating; solar wind-magnetosphere interactions) – Ionosphere (modeling and forecasting) |
format |
Article in Journal/Newspaper |
author |
A. J. Kavanagh M. J. Kosch F. Honary A. Senior S. R. Marple E. E. Woodfield I. W. McCrea |
author_facet |
A. J. Kavanagh M. J. Kosch F. Honary A. Senior S. R. Marple E. E. Woodfield I. W. McCrea |
author_sort |
A. J. Kavanagh |
title |
The statistical dependence of auroral absorption on geomagnetic and solar wind parameters |
title_short |
The statistical dependence of auroral absorption on geomagnetic and solar wind parameters |
title_full |
The statistical dependence of auroral absorption on geomagnetic and solar wind parameters |
title_fullStr |
The statistical dependence of auroral absorption on geomagnetic and solar wind parameters |
title_full_unstemmed |
The statistical dependence of auroral absorption on geomagnetic and solar wind parameters |
title_sort |
statistical dependence of auroral absorption on geomagnetic and solar wind parameters |
publisher |
Copernicus Publications |
publishDate |
2004 |
url |
https://doi.org/10.5194/angeo-22-877-2004 https://doaj.org/article/db02aa24136e450a8c8234438b4dbb48 |
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 22, Pp 877-887 (2004) |
op_relation |
https://www.ann-geophys.net/22/877/2004/angeo-22-877-2004.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-22-877-2004 0992-7689 1432-0576 https://doaj.org/article/db02aa24136e450a8c8234438b4dbb48 |
op_doi |
https://doi.org/10.5194/angeo-22-877-2004 |
container_title |
Annales Geophysicae |
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22 |
container_issue |
3 |
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877 |
op_container_end_page |
887 |
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1766057657186123776 |