A study of the dusk convection cell's response to an IMF southward turning
International audience One example of the response of ionospheric convection and the polar cap boundary to a sudden change in the interplanetary magnetic field (IMF) orientation has been studied by using ground magnetometers, the Super Dual Auroral Radar Network (SuperDARN), and Defense Meteorologic...
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ftinsu:oai:HAL:insu-03039703v1 2024-04-28T08:22:22+00:00 A study of the dusk convection cell's response to an IMF southward turning Ogawa, Tadahiko Nishitani, Nozomu Sato, Natsuo Yamagishi, Hisao Pinnock, Mike Villain, Jean-Paul Sofko, George Troshichev, Oleg Solar-Terrestrial Environment Laboratory Nagoya (STEL) Nagoya University National Institute of Polar Research Tokyo (NiPR) British Antarctic Survey (BAS) Natural Environment Research Council (NERC) Laboratoire de physique et chimie de l'environnement (LPCE) Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS) 2002 https://insu.hal.science/insu-03039703 https://insu.hal.science/insu-03039703/document https://insu.hal.science/insu-03039703/file/2001JA900095.pdf https://doi.org/10.1029/2001JA900095 en eng HAL CCSD American Geophysical Union info:eu-repo/semantics/altIdentifier/doi/10.1029/2001JA900095 insu-03039703 https://insu.hal.science/insu-03039703 https://insu.hal.science/insu-03039703/document https://insu.hal.science/insu-03039703/file/2001JA900095.pdf doi:10.1029/2001JA900095 info:eu-repo/semantics/OpenAccess ISSN: 0148-0227 EISSN: 2156-2202 Journal of Geophysical Research https://insu.hal.science/insu-03039703 Journal of Geophysical Research, 2002, 107 (A3), ⟨10.1029/2001JA900095⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2002 ftinsu https://doi.org/10.1029/2001JA900095 2024-04-05T00:39:09Z International audience One example of the response of ionospheric convection and the polar cap boundary to a sudden change in the interplanetary magnetic field (IMF) orientation has been studied by using ground magnetometers, the Super Dual Auroral Radar Network (SuperDARN), and Defense Meteorological Satellite Program (DMSP) particle detectors when the IMF suddenly changed from northward (+6 nT) to strongly southward (À19 nT) at 1716 UT on 5 September 1995. The B z component was fairly constant for $2 hours before and $25 min after the sudden IMF change. The convection flow changed almost simultaneously over a global extent. This initial change of the convection pattern can be characterized by a sudden formation of a large flow vortex in the afternoon sector. This agrees with the earlier findings by Ruohoniemi and Greenwald [1998] and Ridley et al. [1998]. On the other hand, the response of the polar cap boundary (or its proxy) is more complicated. The Saskatoon radar, located in the late morning sector, observed an equatorward shift of the cusp scatter region simultaneously with the initial response of the convection flows. The DMSP particle data also showed a simultaneous equatorward expansion of the auroral oval in the 2100 magnetic local time (MLT) sector. The radar and particle data indicate the immediate equatorward expansion of the precipitation regions in the noon and premidnight sectors. About 10-20 min after the initial change, there were changes observed in the dusk region, namely, an equatorward expansion of the current reversal boundary observed by the Greenland magnetometer chain in the dusk sector between 1740 and 1750 UT and an equatorward expansion of the convection reversal boundary detected by the Stokkseyri, Halley, and Syowa radars. The delayed responses were observed 18-8 min before a substorm onset was recorded at midlatitude stations at 1756 UT. These observations indicate that there were two kinds of ionospheric responses to the southward turning of the IMF; the first response is the ... Article in Journal/Newspaper Greenland Institut national des sciences de l'Univers: HAL-INSU Journal of Geophysical Research 107 A3 |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
spellingShingle |
[SDU]Sciences of the Universe [physics] Ogawa, Tadahiko Nishitani, Nozomu Sato, Natsuo Yamagishi, Hisao Pinnock, Mike Villain, Jean-Paul Sofko, George Troshichev, Oleg A study of the dusk convection cell's response to an IMF southward turning |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience One example of the response of ionospheric convection and the polar cap boundary to a sudden change in the interplanetary magnetic field (IMF) orientation has been studied by using ground magnetometers, the Super Dual Auroral Radar Network (SuperDARN), and Defense Meteorological Satellite Program (DMSP) particle detectors when the IMF suddenly changed from northward (+6 nT) to strongly southward (À19 nT) at 1716 UT on 5 September 1995. The B z component was fairly constant for $2 hours before and $25 min after the sudden IMF change. The convection flow changed almost simultaneously over a global extent. This initial change of the convection pattern can be characterized by a sudden formation of a large flow vortex in the afternoon sector. This agrees with the earlier findings by Ruohoniemi and Greenwald [1998] and Ridley et al. [1998]. On the other hand, the response of the polar cap boundary (or its proxy) is more complicated. The Saskatoon radar, located in the late morning sector, observed an equatorward shift of the cusp scatter region simultaneously with the initial response of the convection flows. The DMSP particle data also showed a simultaneous equatorward expansion of the auroral oval in the 2100 magnetic local time (MLT) sector. The radar and particle data indicate the immediate equatorward expansion of the precipitation regions in the noon and premidnight sectors. About 10-20 min after the initial change, there were changes observed in the dusk region, namely, an equatorward expansion of the current reversal boundary observed by the Greenland magnetometer chain in the dusk sector between 1740 and 1750 UT and an equatorward expansion of the convection reversal boundary detected by the Stokkseyri, Halley, and Syowa radars. The delayed responses were observed 18-8 min before a substorm onset was recorded at midlatitude stations at 1756 UT. These observations indicate that there were two kinds of ionospheric responses to the southward turning of the IMF; the first response is the ... |
author2 |
Solar-Terrestrial Environment Laboratory Nagoya (STEL) Nagoya University National Institute of Polar Research Tokyo (NiPR) British Antarctic Survey (BAS) Natural Environment Research Council (NERC) Laboratoire de physique et chimie de l'environnement (LPCE) Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Ogawa, Tadahiko Nishitani, Nozomu Sato, Natsuo Yamagishi, Hisao Pinnock, Mike Villain, Jean-Paul Sofko, George Troshichev, Oleg |
author_facet |
Ogawa, Tadahiko Nishitani, Nozomu Sato, Natsuo Yamagishi, Hisao Pinnock, Mike Villain, Jean-Paul Sofko, George Troshichev, Oleg |
author_sort |
Ogawa, Tadahiko |
title |
A study of the dusk convection cell's response to an IMF southward turning |
title_short |
A study of the dusk convection cell's response to an IMF southward turning |
title_full |
A study of the dusk convection cell's response to an IMF southward turning |
title_fullStr |
A study of the dusk convection cell's response to an IMF southward turning |
title_full_unstemmed |
A study of the dusk convection cell's response to an IMF southward turning |
title_sort |
study of the dusk convection cell's response to an imf southward turning |
publisher |
HAL CCSD |
publishDate |
2002 |
url |
https://insu.hal.science/insu-03039703 https://insu.hal.science/insu-03039703/document https://insu.hal.science/insu-03039703/file/2001JA900095.pdf https://doi.org/10.1029/2001JA900095 |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
ISSN: 0148-0227 EISSN: 2156-2202 Journal of Geophysical Research https://insu.hal.science/insu-03039703 Journal of Geophysical Research, 2002, 107 (A3), ⟨10.1029/2001JA900095⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2001JA900095 insu-03039703 https://insu.hal.science/insu-03039703 https://insu.hal.science/insu-03039703/document https://insu.hal.science/insu-03039703/file/2001JA900095.pdf doi:10.1029/2001JA900095 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/2001JA900095 |
container_title |
Journal of Geophysical Research |
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107 |
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A3 |
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1797584040212037632 |