Statistical study on the conjugacy of geomagnetic field variations
The diurnal and seasonal dependence of the conjugacy of geomagnetic variations associated with the auroral electrojet is investigated and their dependence on ionospheric conductivity (due to solar EUV and auroral particle precipitations) is examined. We analyze the fluxgate magnetometer data from tw...
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National Institute of Polar Research
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ftdoajarticles:oai:doaj.org/article:e92a0d5b9b90407fb2ae041367f2c093 2023-05-15T13:45:05+02:00 Statistical study on the conjugacy of geomagnetic field variations Kumiko Hashimoto Natsuo Sato Masahiko Kusunose 1993-03-01T00:00:00Z https://doi.org/10.15094/00008797 https://doaj.org/article/e92a0d5b9b90407fb2ae041367f2c093 EN JA eng jpn National Institute of Polar Research http://doi.org/10.15094/00008797 https://doaj.org/toc/0085-7289 https://doaj.org/toc/2432-079X doi:10.15094/00008797 0085-7289 2432-079X https://doaj.org/article/e92a0d5b9b90407fb2ae041367f2c093 Antarctic Record, Vol 37, Iss 1, Pp 1-18 (1993) Geography (General) G1-922 article 1993 ftdoajarticles https://doi.org/10.15094/00008797 2022-12-31T14:08:22Z The diurnal and seasonal dependence of the conjugacy of geomagnetic variations associated with the auroral electrojet is investigated and their dependence on ionospheric conductivity (due to solar EUV and auroral particle precipitations) is examined. We analyze the fluxgate magnetometer data from two magnetic conjugate stations at Syowa in Antarctica and at Aedey in Iceland, during the period from September 1989 to September 1990. Here, a magnitude of geomagnetic variation is defined as a deviation from quiet time geomagnetic elements for each month. We further examined a ratio of the magnitudes of the geomagnetic variations between two stations (ΔHSYOWA/ΔHAEDEY). Principal characteristics of the magnitude ratio between two conjugate observatories include the following : When the sense of magnetic variations of H component is positive (northward), the magnitude in the summer hemisphere is about three times larger than that in the winter hemisphere during 1300-2000 UT, and the magnitude ratio becomes largest around 1800 UT in the northern summer. Almost the same magnitude of geomagnetic variations at the two observatories appeared at around 1800 UT in February and October. On the other hand, for negative variation (southward), a similar seasonal change can be seen only under low magnetic activity conditions. The magnitude ratio for the negative variation is always smaller than that for the positive one. The ratios are equal around 0600 UT in April and August. The magnitude of geomagnetic variation showed dependence on the geomagnetic activity level. Generally, in all seasons, the magnitude at Syowa shows to be larger than that at Aedey relatively for both positive and negative variations with geomagnetic activity level. These results are consistent with the diurnal and seasonal change of the ionospheres depending on the sunlit conditions. We further examined the effects of ionization made by auroral particle precipitations. Article in Journal/Newspaper Antarc* Antarctica Iceland Directory of Open Access Journals: DOAJ Articles |
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Directory of Open Access Journals: DOAJ Articles |
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language |
English Japanese |
topic |
Geography (General) G1-922 |
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Geography (General) G1-922 Kumiko Hashimoto Natsuo Sato Masahiko Kusunose Statistical study on the conjugacy of geomagnetic field variations |
topic_facet |
Geography (General) G1-922 |
description |
The diurnal and seasonal dependence of the conjugacy of geomagnetic variations associated with the auroral electrojet is investigated and their dependence on ionospheric conductivity (due to solar EUV and auroral particle precipitations) is examined. We analyze the fluxgate magnetometer data from two magnetic conjugate stations at Syowa in Antarctica and at Aedey in Iceland, during the period from September 1989 to September 1990. Here, a magnitude of geomagnetic variation is defined as a deviation from quiet time geomagnetic elements for each month. We further examined a ratio of the magnitudes of the geomagnetic variations between two stations (ΔHSYOWA/ΔHAEDEY). Principal characteristics of the magnitude ratio between two conjugate observatories include the following : When the sense of magnetic variations of H component is positive (northward), the magnitude in the summer hemisphere is about three times larger than that in the winter hemisphere during 1300-2000 UT, and the magnitude ratio becomes largest around 1800 UT in the northern summer. Almost the same magnitude of geomagnetic variations at the two observatories appeared at around 1800 UT in February and October. On the other hand, for negative variation (southward), a similar seasonal change can be seen only under low magnetic activity conditions. The magnitude ratio for the negative variation is always smaller than that for the positive one. The ratios are equal around 0600 UT in April and August. The magnitude of geomagnetic variation showed dependence on the geomagnetic activity level. Generally, in all seasons, the magnitude at Syowa shows to be larger than that at Aedey relatively for both positive and negative variations with geomagnetic activity level. These results are consistent with the diurnal and seasonal change of the ionospheres depending on the sunlit conditions. We further examined the effects of ionization made by auroral particle precipitations. |
format |
Article in Journal/Newspaper |
author |
Kumiko Hashimoto Natsuo Sato Masahiko Kusunose |
author_facet |
Kumiko Hashimoto Natsuo Sato Masahiko Kusunose |
author_sort |
Kumiko Hashimoto |
title |
Statistical study on the conjugacy of geomagnetic field variations |
title_short |
Statistical study on the conjugacy of geomagnetic field variations |
title_full |
Statistical study on the conjugacy of geomagnetic field variations |
title_fullStr |
Statistical study on the conjugacy of geomagnetic field variations |
title_full_unstemmed |
Statistical study on the conjugacy of geomagnetic field variations |
title_sort |
statistical study on the conjugacy of geomagnetic field variations |
publisher |
National Institute of Polar Research |
publishDate |
1993 |
url |
https://doi.org/10.15094/00008797 https://doaj.org/article/e92a0d5b9b90407fb2ae041367f2c093 |
genre |
Antarc* Antarctica Iceland |
genre_facet |
Antarc* Antarctica Iceland |
op_source |
Antarctic Record, Vol 37, Iss 1, Pp 1-18 (1993) |
op_relation |
http://doi.org/10.15094/00008797 https://doaj.org/toc/0085-7289 https://doaj.org/toc/2432-079X doi:10.15094/00008797 0085-7289 2432-079X https://doaj.org/article/e92a0d5b9b90407fb2ae041367f2c093 |
op_doi |
https://doi.org/10.15094/00008797 |
_version_ |
1766212556918095872 |