A model for estimating the relation between the Hall to Pedersen conductance ratio and ground magnetic data derived from CHAMP satellite statistics
The goal of this study is to find a way to statistically estimate the Hall to Pedersen conductance ratio α from ground magnetic data. We use vector magnetic data from the CHAMP satellite to derive this relation. α is attained from magnetic satellite data using the 1-D Spherical Elementary Current Sy...
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ftdoajarticles:oai:doaj.org/article:da35591f91be43cbadcd42001e9c8a23 2023-05-15T16:04:50+02:00 A model for estimating the relation between the Hall to Pedersen conductance ratio and ground magnetic data derived from CHAMP satellite statistics L. Juusola O. Amm K. Kauristie A. Viljanen 2007-03-01T00:00:00Z https://doi.org/10.5194/angeo-25-721-2007 https://doaj.org/article/da35591f91be43cbadcd42001e9c8a23 EN eng Copernicus Publications https://www.ann-geophys.net/25/721/2007/angeo-25-721-2007.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-25-721-2007 0992-7689 1432-0576 https://doaj.org/article/da35591f91be43cbadcd42001e9c8a23 Annales Geophysicae, Vol 25, Pp 721-736 (2007) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2007 ftdoajarticles https://doi.org/10.5194/angeo-25-721-2007 2022-12-31T03:04:03Z The goal of this study is to find a way to statistically estimate the Hall to Pedersen conductance ratio α from ground magnetic data. We use vector magnetic data from the CHAMP satellite to derive this relation. α is attained from magnetic satellite data using the 1-D Spherical Elementary Current Systems (SECS). The ionospheric equivalent current density can either be computed from ground or satellite magnetic data. Under the required 1-D assumption, these two approaches are shown to be equal, which leads to the advantage that the statistics are not restricted to areas covered by ground data. Unlike other methods, using magnetic satellite measurements to determine α ensures reliable data over long time sequences. The statistical study, comprising over 6000 passes between 55° and 76.5° northern geomagnetic latitude during 2001 and 2002, is carried out employing data from the CHAMP satellite. The data are binned according to activity and season. In agreement with earlier studies, values between 1 and 3 are typically found for α. Good compatibility is found, when α attained from CHAMP data is compared with EISCAT radar measurements. The results make it possible to estimate α from the east-west equivalent current density J ϕ [A/km]: α=2.07/(36.54/| J ϕ |+1) for J ϕ <0 (westward) and α=1.73/(14.79/| J ϕ +1) for J ϕ 0 (eastward). Using the same data, statistics of ionospheric and field-aligned current densities as a function of geomagnetic latitude and MLT are included. These are binned with respect to activity, season and IMF B Z and B Y . For the first time, all three current density components are simultaneously studied this way on a comparable spatial scale. With increasing activity, the enhancement and the equatorward expansion of the electrojets and the R1 and R2 currents is observed, and in the nightside, possible indications of a Cowling channel appear. During southward IMF B Z , the electrojets and the R1 and R2 currents are stronger and clearer than during northward B Z . IMF B Y affects the orientation ... Article in Journal/Newspaper EISCAT Directory of Open Access Journals: DOAJ Articles Pedersen ENVELOPE(140.013,140.013,-66.668,-66.668) Annales Geophysicae 25 3 721 736 |
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Open Polar |
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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 L. Juusola O. Amm K. Kauristie A. Viljanen A model for estimating the relation between the Hall to Pedersen conductance ratio and ground magnetic data derived from CHAMP satellite statistics |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
The goal of this study is to find a way to statistically estimate the Hall to Pedersen conductance ratio α from ground magnetic data. We use vector magnetic data from the CHAMP satellite to derive this relation. α is attained from magnetic satellite data using the 1-D Spherical Elementary Current Systems (SECS). The ionospheric equivalent current density can either be computed from ground or satellite magnetic data. Under the required 1-D assumption, these two approaches are shown to be equal, which leads to the advantage that the statistics are not restricted to areas covered by ground data. Unlike other methods, using magnetic satellite measurements to determine α ensures reliable data over long time sequences. The statistical study, comprising over 6000 passes between 55° and 76.5° northern geomagnetic latitude during 2001 and 2002, is carried out employing data from the CHAMP satellite. The data are binned according to activity and season. In agreement with earlier studies, values between 1 and 3 are typically found for α. Good compatibility is found, when α attained from CHAMP data is compared with EISCAT radar measurements. The results make it possible to estimate α from the east-west equivalent current density J ϕ [A/km]: α=2.07/(36.54/| J ϕ |+1) for J ϕ <0 (westward) and α=1.73/(14.79/| J ϕ +1) for J ϕ 0 (eastward). Using the same data, statistics of ionospheric and field-aligned current densities as a function of geomagnetic latitude and MLT are included. These are binned with respect to activity, season and IMF B Z and B Y . For the first time, all three current density components are simultaneously studied this way on a comparable spatial scale. With increasing activity, the enhancement and the equatorward expansion of the electrojets and the R1 and R2 currents is observed, and in the nightside, possible indications of a Cowling channel appear. During southward IMF B Z , the electrojets and the R1 and R2 currents are stronger and clearer than during northward B Z . IMF B Y affects the orientation ... |
format |
Article in Journal/Newspaper |
author |
L. Juusola O. Amm K. Kauristie A. Viljanen |
author_facet |
L. Juusola O. Amm K. Kauristie A. Viljanen |
author_sort |
L. Juusola |
title |
A model for estimating the relation between the Hall to Pedersen conductance ratio and ground magnetic data derived from CHAMP satellite statistics |
title_short |
A model for estimating the relation between the Hall to Pedersen conductance ratio and ground magnetic data derived from CHAMP satellite statistics |
title_full |
A model for estimating the relation between the Hall to Pedersen conductance ratio and ground magnetic data derived from CHAMP satellite statistics |
title_fullStr |
A model for estimating the relation between the Hall to Pedersen conductance ratio and ground magnetic data derived from CHAMP satellite statistics |
title_full_unstemmed |
A model for estimating the relation between the Hall to Pedersen conductance ratio and ground magnetic data derived from CHAMP satellite statistics |
title_sort |
model for estimating the relation between the hall to pedersen conductance ratio and ground magnetic data derived from champ satellite statistics |
publisher |
Copernicus Publications |
publishDate |
2007 |
url |
https://doi.org/10.5194/angeo-25-721-2007 https://doaj.org/article/da35591f91be43cbadcd42001e9c8a23 |
long_lat |
ENVELOPE(140.013,140.013,-66.668,-66.668) |
geographic |
Pedersen |
geographic_facet |
Pedersen |
genre |
EISCAT |
genre_facet |
EISCAT |
op_source |
Annales Geophysicae, Vol 25, Pp 721-736 (2007) |
op_relation |
https://www.ann-geophys.net/25/721/2007/angeo-25-721-2007.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-25-721-2007 0992-7689 1432-0576 https://doaj.org/article/da35591f91be43cbadcd42001e9c8a23 |
op_doi |
https://doi.org/10.5194/angeo-25-721-2007 |
container_title |
Annales Geophysicae |
container_volume |
25 |
container_issue |
3 |
container_start_page |
721 |
op_container_end_page |
736 |
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1766400482723495936 |