A study of the dusk convection cell's response to an IMF southward turning
[1] 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 Progra...
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ftnerc:oai:nora.nerc.ac.uk:13599 2023-05-15T16:30:15+02:00 A study of the dusk convection cell's response to an IMF southward turning Nishitani, Nozomu Ogawa, Tadahiko Sato, Natsuo Yamagishi, Hisao Pinnock, Mike Villain, Jean-Paul Sofko, George Troshichev, Oleg 2002 http://nora.nerc.ac.uk/id/eprint/13599/ http://www.agu.org/journals/ja/ja0203/2001JA900095/2001JA900095.pdf unknown American Geophysical Union Nishitani, Nozomu; Ogawa, Tadahiko; Sato, Natsuo; Yamagishi, Hisao; Pinnock, Mike; Villain, Jean-Paul; Sofko, George; Troshichev, Oleg. 2002 A study of the dusk convection cell's response to an IMF southward turning. Journal of Geophysical Research, 107 (A3), 1036. 15, pp. https://doi.org/10.1029/2001JA900095 <https://doi.org/10.1029/2001JA900095> Physics Atmospheric Sciences Publication - Article PeerReviewed 2002 ftnerc https://doi.org/10.1029/2001JA900095 2023-02-04T19:28:43Z [1] 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 (-19 nT) at 1716 UT on 5 September 1995. The B-z component was fairly constant for similar to2 hours before and similar to25 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 Natural Environment Research Council: NERC Open Research Archive Greenland Ridley ENVELOPE(-130.315,-130.315,54.250,54.250) Stokkseyri ENVELOPE(-21.059,-21.059,63.838,63.838) Journal of Geophysical Research 107 A3 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Physics Atmospheric Sciences |
spellingShingle |
Physics Atmospheric Sciences Nishitani, Nozomu Ogawa, Tadahiko 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 |
Physics Atmospheric Sciences |
description |
[1] 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 (-19 nT) at 1716 UT on 5 September 1995. The B-z component was fairly constant for similar to2 hours before and similar to25 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 ... |
format |
Article in Journal/Newspaper |
author |
Nishitani, Nozomu Ogawa, Tadahiko Sato, Natsuo Yamagishi, Hisao Pinnock, Mike Villain, Jean-Paul Sofko, George Troshichev, Oleg |
author_facet |
Nishitani, Nozomu Ogawa, Tadahiko Sato, Natsuo Yamagishi, Hisao Pinnock, Mike Villain, Jean-Paul Sofko, George Troshichev, Oleg |
author_sort |
Nishitani, Nozomu |
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 |
American Geophysical Union |
publishDate |
2002 |
url |
http://nora.nerc.ac.uk/id/eprint/13599/ http://www.agu.org/journals/ja/ja0203/2001JA900095/2001JA900095.pdf |
long_lat |
ENVELOPE(-130.315,-130.315,54.250,54.250) ENVELOPE(-21.059,-21.059,63.838,63.838) |
geographic |
Greenland Ridley Stokkseyri |
geographic_facet |
Greenland Ridley Stokkseyri |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
Nishitani, Nozomu; Ogawa, Tadahiko; Sato, Natsuo; Yamagishi, Hisao; Pinnock, Mike; Villain, Jean-Paul; Sofko, George; Troshichev, Oleg. 2002 A study of the dusk convection cell's response to an IMF southward turning. Journal of Geophysical Research, 107 (A3), 1036. 15, pp. https://doi.org/10.1029/2001JA900095 <https://doi.org/10.1029/2001JA900095> |
op_doi |
https://doi.org/10.1029/2001JA900095 |
container_title |
Journal of Geophysical Research |
container_volume |
107 |
container_issue |
A3 |
_version_ |
1766019964721954816 |