The dawn and dusk electrojet response to substorm onset
International audience We have investigated the time delay between substorm onset and related reactions in the dawn and dusk ionospheric electrojets, clearly separated from the nightside located substorm current wedge by several hours in MLT. We looked for substorm onsets occurring over Greenland, w...
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ftccsdartic:oai:HAL:hal-00316782v1 2023-11-12T04:16:38+01:00 The dawn and dusk electrojet response to substorm onset Borälv, E. Eglitis, P. Opgenoorth, H. J. Donovan, E. Reeves, G. Stauning, P. Swedish Institute of Space Physics Kiruna (IRF) Finnish Meteorological Institute (FMI) Department of Physics and Astronomy Calgary University of Calgary Los Alamos National Laboratory (LANL) Solar-Terrestrial Physics Division Copenhagen Danish Meteorological Institute (DMI) 2000 https://hal.science/hal-00316782 https://hal.science/hal-00316782/document https://hal.science/hal-00316782/file/angeo-18-1097-2000.pdf en eng HAL CCSD European Geosciences Union hal-00316782 https://hal.science/hal-00316782 https://hal.science/hal-00316782/document https://hal.science/hal-00316782/file/angeo-18-1097-2000.pdf info:eu-repo/semantics/OpenAccess ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00316782 Annales Geophysicae, 2000, 18 (9), pp.1097-1107 [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 ftccsdartic 2023-10-21T23:08:10Z International audience We have investigated the time delay between substorm onset and related reactions in the dawn and dusk ionospheric electrojets, clearly separated from the nightside located substorm current wedge by several hours in MLT. We looked for substorm onsets occurring over Greenland, where the onset was identified by a LANL satellite and DMI magnetometers located on Greenland. With this setup the MARIA magnetometer network was located at dusk, monitoring the eastward electrojet, and the IMAGE chain at dawn, for the westward jet. In the first few minutes following substorm onset, sudden enhancements of the electrojets were identified by looking for rapid changes in magnetograms. These results show that the speed of information transfer between the region of onset and the dawn and dusk ionosphere is very high. A number of events where the reaction seemed to preceed the onset were explained by either unfavorable instrument locations, preventing proper onset timing, or by the inner magnetosphere's reaction to the Earthward fast flows from the near-Earth neutral line model. Case studies with ionospheric coherent (SuperDARN) and incoherent (EISCAT) radars have been performed to see whether a convection-induced electric field or enhanced conductivity is the main agent for the reactions in the electrojets. The results indicate an imposed electric field enhancement. Key words: Ionosphere (auroral ionosphere; electric fields and currents) - Magnetospheric physics (storms and substorms) Article in Journal/Newspaper EISCAT Greenland Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Greenland |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
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 Borälv, E. Eglitis, P. Opgenoorth, H. J. Donovan, E. Reeves, G. Stauning, P. The dawn and dusk electrojet response to substorm onset |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience We have investigated the time delay between substorm onset and related reactions in the dawn and dusk ionospheric electrojets, clearly separated from the nightside located substorm current wedge by several hours in MLT. We looked for substorm onsets occurring over Greenland, where the onset was identified by a LANL satellite and DMI magnetometers located on Greenland. With this setup the MARIA magnetometer network was located at dusk, monitoring the eastward electrojet, and the IMAGE chain at dawn, for the westward jet. In the first few minutes following substorm onset, sudden enhancements of the electrojets were identified by looking for rapid changes in magnetograms. These results show that the speed of information transfer between the region of onset and the dawn and dusk ionosphere is very high. A number of events where the reaction seemed to preceed the onset were explained by either unfavorable instrument locations, preventing proper onset timing, or by the inner magnetosphere's reaction to the Earthward fast flows from the near-Earth neutral line model. Case studies with ionospheric coherent (SuperDARN) and incoherent (EISCAT) radars have been performed to see whether a convection-induced electric field or enhanced conductivity is the main agent for the reactions in the electrojets. The results indicate an imposed electric field enhancement. Key words: Ionosphere (auroral ionosphere; electric fields and currents) - Magnetospheric physics (storms and substorms) |
author2 |
Swedish Institute of Space Physics Kiruna (IRF) Finnish Meteorological Institute (FMI) Department of Physics and Astronomy Calgary University of Calgary Los Alamos National Laboratory (LANL) Solar-Terrestrial Physics Division Copenhagen Danish Meteorological Institute (DMI) |
format |
Article in Journal/Newspaper |
author |
Borälv, E. Eglitis, P. Opgenoorth, H. J. Donovan, E. Reeves, G. Stauning, P. |
author_facet |
Borälv, E. Eglitis, P. Opgenoorth, H. J. Donovan, E. Reeves, G. Stauning, P. |
author_sort |
Borälv, E. |
title |
The dawn and dusk electrojet response to substorm onset |
title_short |
The dawn and dusk electrojet response to substorm onset |
title_full |
The dawn and dusk electrojet response to substorm onset |
title_fullStr |
The dawn and dusk electrojet response to substorm onset |
title_full_unstemmed |
The dawn and dusk electrojet response to substorm onset |
title_sort |
dawn and dusk electrojet response to substorm onset |
publisher |
HAL CCSD |
publishDate |
2000 |
url |
https://hal.science/hal-00316782 https://hal.science/hal-00316782/document https://hal.science/hal-00316782/file/angeo-18-1097-2000.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
EISCAT Greenland |
genre_facet |
EISCAT Greenland |
op_source |
ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00316782 Annales Geophysicae, 2000, 18 (9), pp.1097-1107 |
op_relation |
hal-00316782 https://hal.science/hal-00316782 https://hal.science/hal-00316782/document https://hal.science/hal-00316782/file/angeo-18-1097-2000.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782333706513416192 |