A multipoint study of a substorm occurring on 7 December, 1992, and its theoretical implications
On 7 December 1992, a moderate substorm was observed by a variety of satellites and ground-based instruments. Ionospheric flows were monitored near dusk by the Goose Bay HF radar and near midnight by the EISCAT radar. The observed flows are compared here with magnetometer observations by the IMAGE a...
Published in: | Annales Geophysicae |
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Springer Verlag
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00036917 2023-05-15T16:04:47+02:00 A multipoint study of a substorm occurring on 7 December, 1992, and its theoretical implications Fox, N. J. Cowley, S. W. H. Davda, V. N. Enno, G. Friis-Christensen, E. Greenwald, R. A. Hairston, M. R. Lester, M. Lockwood, M. Lühr, H. Milling, D. K. Murphree, J. S. Pinnock, M. Reeves, G. D. 1999-11 electronic https://doi.org/10.1007/s00585-999-1369-6 https://noa.gwlb.de/receive/cop_mods_00036917 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00036871/angeo-17-1369-1999.pdf https://angeo.copernicus.org/articles/17/1369/1999/angeo-17-1369-1999.pdf eng eng Springer Verlag Annales Geophysicae -- http://www.bibliothek.uni-regensburg.de/ezeit/?1458425 -- https://www.ann-geophys.net/ -- https://www.ann-geophys.net/volumes.html -- http://link.springer.com/journal/585 -- 1432-0576 https://doi.org/10.1007/s00585-999-1369-6 https://noa.gwlb.de/receive/cop_mods_00036917 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00036871/angeo-17-1369-1999.pdf https://angeo.copernicus.org/articles/17/1369/1999/angeo-17-1369-1999.pdf https://open-access.net/ uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 1999 ftnonlinearchiv https://doi.org/10.1007/s00585-999-1369-6 2022-02-08T22:43:45Z On 7 December 1992, a moderate substorm was observed by a variety of satellites and ground-based instruments. Ionospheric flows were monitored near dusk by the Goose Bay HF radar and near midnight by the EISCAT radar. The observed flows are compared here with magnetometer observations by the IMAGE array in Scandinavia and the two Greenland chains, the auroral distribution observed by Freja and the substorm cycle observations by the SABRE radar, the SAMNET magnetometer array and LANL geosynchronous satellites. Data from Galileo Earth-encounter II are used to estimate the IMF Bz component. The data presented show that the substorm onset electrojet at midnight was confined to closed field lines equatorward of the pre-existing convection reversal boundaries observed in the dusk and midnight regions. No evidence of substantial closure of open flux was detected following this substorm onset. Indeed the convection reversal boundary on the duskside continued to expand equatorward after onset due to the continued presence of strong southward IMF, such that growth and expansion phase features were simultaneously present. Clear indications of closure of open flux were not observed until a subsequent substorm intensification 25 min after the initial onset. After this time, the substorm auroral bulge in the nightside hours propagated well poleward of the pre-existing convection reversal boundary, and strong flow perturbations were observed by the Goose Bay radar, indicative of flows driven by reconnection in the tail. Key words. Ionosphere (auroral ionosphere; plasma convection) · Magnetospheric physics (storms and substorms) Article in Journal/Newspaper EISCAT Greenland Niedersächsisches Online-Archiv NOA Greenland Annales Geophysicae 17 11 1369 1384 |
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Niedersächsisches Online-Archiv NOA |
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English |
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article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Fox, N. J. Cowley, S. W. H. Davda, V. N. Enno, G. Friis-Christensen, E. Greenwald, R. A. Hairston, M. R. Lester, M. Lockwood, M. Lühr, H. Milling, D. K. Murphree, J. S. Pinnock, M. Reeves, G. D. A multipoint study of a substorm occurring on 7 December, 1992, and its theoretical implications |
topic_facet |
article Verlagsveröffentlichung |
description |
On 7 December 1992, a moderate substorm was observed by a variety of satellites and ground-based instruments. Ionospheric flows were monitored near dusk by the Goose Bay HF radar and near midnight by the EISCAT radar. The observed flows are compared here with magnetometer observations by the IMAGE array in Scandinavia and the two Greenland chains, the auroral distribution observed by Freja and the substorm cycle observations by the SABRE radar, the SAMNET magnetometer array and LANL geosynchronous satellites. Data from Galileo Earth-encounter II are used to estimate the IMF Bz component. The data presented show that the substorm onset electrojet at midnight was confined to closed field lines equatorward of the pre-existing convection reversal boundaries observed in the dusk and midnight regions. No evidence of substantial closure of open flux was detected following this substorm onset. Indeed the convection reversal boundary on the duskside continued to expand equatorward after onset due to the continued presence of strong southward IMF, such that growth and expansion phase features were simultaneously present. Clear indications of closure of open flux were not observed until a subsequent substorm intensification 25 min after the initial onset. After this time, the substorm auroral bulge in the nightside hours propagated well poleward of the pre-existing convection reversal boundary, and strong flow perturbations were observed by the Goose Bay radar, indicative of flows driven by reconnection in the tail. Key words. Ionosphere (auroral ionosphere; plasma convection) · Magnetospheric physics (storms and substorms) |
format |
Article in Journal/Newspaper |
author |
Fox, N. J. Cowley, S. W. H. Davda, V. N. Enno, G. Friis-Christensen, E. Greenwald, R. A. Hairston, M. R. Lester, M. Lockwood, M. Lühr, H. Milling, D. K. Murphree, J. S. Pinnock, M. Reeves, G. D. |
author_facet |
Fox, N. J. Cowley, S. W. H. Davda, V. N. Enno, G. Friis-Christensen, E. Greenwald, R. A. Hairston, M. R. Lester, M. Lockwood, M. Lühr, H. Milling, D. K. Murphree, J. S. Pinnock, M. Reeves, G. D. |
author_sort |
Fox, N. J. |
title |
A multipoint study of a substorm occurring on 7 December, 1992, and its theoretical implications |
title_short |
A multipoint study of a substorm occurring on 7 December, 1992, and its theoretical implications |
title_full |
A multipoint study of a substorm occurring on 7 December, 1992, and its theoretical implications |
title_fullStr |
A multipoint study of a substorm occurring on 7 December, 1992, and its theoretical implications |
title_full_unstemmed |
A multipoint study of a substorm occurring on 7 December, 1992, and its theoretical implications |
title_sort |
multipoint study of a substorm occurring on 7 december, 1992, and its theoretical implications |
publisher |
Springer Verlag |
publishDate |
1999 |
url |
https://doi.org/10.1007/s00585-999-1369-6 https://noa.gwlb.de/receive/cop_mods_00036917 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00036871/angeo-17-1369-1999.pdf https://angeo.copernicus.org/articles/17/1369/1999/angeo-17-1369-1999.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
EISCAT Greenland |
genre_facet |
EISCAT Greenland |
op_relation |
Annales Geophysicae -- http://www.bibliothek.uni-regensburg.de/ezeit/?1458425 -- https://www.ann-geophys.net/ -- https://www.ann-geophys.net/volumes.html -- http://link.springer.com/journal/585 -- 1432-0576 https://doi.org/10.1007/s00585-999-1369-6 https://noa.gwlb.de/receive/cop_mods_00036917 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00036871/angeo-17-1369-1999.pdf https://angeo.copernicus.org/articles/17/1369/1999/angeo-17-1369-1999.pdf |
op_rights |
https://open-access.net/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1007/s00585-999-1369-6 |
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Annales Geophysicae |
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17 |
container_issue |
11 |
container_start_page |
1369 |
op_container_end_page |
1384 |
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1766400422953615360 |