The effect of magnetic substorms on near-ground atmospheric current
International audience Ionosphere-magnetosphere disturbances at high latitudes, e.g. magnetic substorms, are accompanied by energetic particle precipitation and strong variations of the ionospheric electric fields and currents. These might reasonably be expected to modify the local atmospheric elect...
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ftinsu:oai:HAL:hal-00316832v1 2023-11-12T04:23:24+01:00 The effect of magnetic substorms on near-ground atmospheric current Belova, E. Kirkwood, S. Tammet, H. MRI Atmospheric Research Programme Swedish Institute of Space Physics Kiruna (IRF) Laboratory of Environmental Physics Tartu University of Tartu 2000 https://hal.science/hal-00316832 https://hal.science/hal-00316832/document https://hal.science/hal-00316832/file/angeo-18-1623-2000.pdf en eng HAL CCSD European Geosciences Union hal-00316832 https://hal.science/hal-00316832 https://hal.science/hal-00316832/document https://hal.science/hal-00316832/file/angeo-18-1623-2000.pdf info:eu-repo/semantics/OpenAccess ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00316832 Annales Geophysicae, 2000, 18 (12), pp.1623-1629 [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2000 ftinsu 2023-10-25T16:25:30Z International audience Ionosphere-magnetosphere disturbances at high latitudes, e.g. magnetic substorms, are accompanied by energetic particle precipitation and strong variations of the ionospheric electric fields and currents. These might reasonably be expected to modify the local atmospheric electric circuit. We have analysed air-earth vertical currents (AECs) measured by a long wire antenna at Esrange, northern Sweden during 35 geomagnetic substorms. Using superposed epoch analysis we compare the air-earth current variations during the 3 h before and after the time of the magnetic X-component minimum with those for corresponding local times on 35 days without substorms. After elimination of the average daily variation we can conclude that the effect of substorms on AEC is small but distinguishable. It is speculated that the AEC increases observed during about 2 h prior to the geomagnetic X-component minimum, are due to enhancement of the ionospheric electric field. During the subsequent 2 h of the substorm recovery phase, the difference between "substorm" and "quiet" atmospheric currents decreases. The amplitude of this "substorm" variation of AEC is estimated to be less than 50% of the amplitude of the diurnal variation in AEC during the same time interval . The statistical significance of this result was confirmed using the Van der Waerden X-test. This method was further used to show that the average air-earth current and its fluctuations increase during late expansion and early recovery phases of substorms. Key words: Ionosphere (electric fields and currents) · Magnetospheric physics (storms and substorms) · Meteorology and atmospheric dynamics (atmospheric electricity) Article in Journal/Newspaper Northern Sweden Institut national des sciences de l'Univers: HAL-INSU Esrange ENVELOPE(21.117,21.117,67.883,67.883) |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Belova, E. Kirkwood, S. Tammet, H. The effect of magnetic substorms on near-ground atmospheric current |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience Ionosphere-magnetosphere disturbances at high latitudes, e.g. magnetic substorms, are accompanied by energetic particle precipitation and strong variations of the ionospheric electric fields and currents. These might reasonably be expected to modify the local atmospheric electric circuit. We have analysed air-earth vertical currents (AECs) measured by a long wire antenna at Esrange, northern Sweden during 35 geomagnetic substorms. Using superposed epoch analysis we compare the air-earth current variations during the 3 h before and after the time of the magnetic X-component minimum with those for corresponding local times on 35 days without substorms. After elimination of the average daily variation we can conclude that the effect of substorms on AEC is small but distinguishable. It is speculated that the AEC increases observed during about 2 h prior to the geomagnetic X-component minimum, are due to enhancement of the ionospheric electric field. During the subsequent 2 h of the substorm recovery phase, the difference between "substorm" and "quiet" atmospheric currents decreases. The amplitude of this "substorm" variation of AEC is estimated to be less than 50% of the amplitude of the diurnal variation in AEC during the same time interval . The statistical significance of this result was confirmed using the Van der Waerden X-test. This method was further used to show that the average air-earth current and its fluctuations increase during late expansion and early recovery phases of substorms. Key words: Ionosphere (electric fields and currents) · Magnetospheric physics (storms and substorms) · Meteorology and atmospheric dynamics (atmospheric electricity) |
author2 |
MRI Atmospheric Research Programme Swedish Institute of Space Physics Kiruna (IRF) Laboratory of Environmental Physics Tartu University of Tartu |
format |
Article in Journal/Newspaper |
author |
Belova, E. Kirkwood, S. Tammet, H. |
author_facet |
Belova, E. Kirkwood, S. Tammet, H. |
author_sort |
Belova, E. |
title |
The effect of magnetic substorms on near-ground atmospheric current |
title_short |
The effect of magnetic substorms on near-ground atmospheric current |
title_full |
The effect of magnetic substorms on near-ground atmospheric current |
title_fullStr |
The effect of magnetic substorms on near-ground atmospheric current |
title_full_unstemmed |
The effect of magnetic substorms on near-ground atmospheric current |
title_sort |
effect of magnetic substorms on near-ground atmospheric current |
publisher |
HAL CCSD |
publishDate |
2000 |
url |
https://hal.science/hal-00316832 https://hal.science/hal-00316832/document https://hal.science/hal-00316832/file/angeo-18-1623-2000.pdf |
long_lat |
ENVELOPE(21.117,21.117,67.883,67.883) |
geographic |
Esrange |
geographic_facet |
Esrange |
genre |
Northern Sweden |
genre_facet |
Northern Sweden |
op_source |
ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00316832 Annales Geophysicae, 2000, 18 (12), pp.1623-1629 |
op_relation |
hal-00316832 https://hal.science/hal-00316832 https://hal.science/hal-00316832/document https://hal.science/hal-00316832/file/angeo-18-1623-2000.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782338182545670144 |