Preliminary two-point observations of the mid-altitude cusp by Cluster PEACE and FGM

On 1 October 2000, Cluster spacecraft Samba (Cluster 3) and Tango (Cluster 4) made an outbound crossing of the northern mid-altitude (4.7 <i>R<sub>E</sub></i>) cusp region, moving roughly parallel to the noon meridian. We present preliminary observations from this int...

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Main Authors: I. Krauklis, A. N. Fazakerley, C. J. Owen, P. J. Carter, M. W. Dunlop, A. J. Coates, S. Szita, M. G. G. T. Taylor, P. Travnicek, G. Watson, R. J. Wilson
Format: Article
Language:English
Published: Copernicus Publications 2001-09-01
Series:Annales Geophysicae
Online Access:https://www.ann-geophys.net/19/1579/2001/angeo-19-1579-2001.pdf
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author I. Krauklis
A. N. Fazakerley
C. J. Owen
P. J. Carter
M. W. Dunlop
A. J. Coates
S. Szita
M. G. G. T. Taylor
P. Travnicek
G. Watson
R. J. Wilson
author_facet I. Krauklis
A. N. Fazakerley
C. J. Owen
P. J. Carter
M. W. Dunlop
A. J. Coates
S. Szita
M. G. G. T. Taylor
P. Travnicek
G. Watson
R. J. Wilson
author_sort I. Krauklis
collection DOAJ
description On 1 October 2000, Cluster spacecraft Samba (Cluster 3) and Tango (Cluster 4) made an outbound crossing of the northern mid-altitude (4.7 <i>R<sub>E</sub></i>) cusp region, moving roughly parallel to the noon meridian. We present preliminary observations from this interval made by the PEACE and FGM instruments. The interplanetary magnetic field at the magnetopause is estimated to have turned south at the time of our observations, based on ACE data as well as a rough estimate of the time taken for the solar wind to travel between ACE and the magnetopause. Cluster 3 encountered the low-latitude boundary layer (LLBL) between 12:20:30 to 12:26:00 UT, and the cusp region between 12:26:00 and 12:32:30 UT. Cluster 4 encountered the LLBL between 12:22:00 to 12:29:00 UT, and the cusp region between 12:29:00 and 12:38:00 UT. During the interval between the two spacecraft passages through these regions, the open/closed field line boundary was observed to move equatorward by 0.33° invariant latitude, while the latitudinal extent of the cusp region increased by 0.5°. Both of these observations are consistent with the ongoing reconnection at the sub-solar magnetopause. The magnetic field data indicate that Cluster encountered four field-aligned longitudinally extended current sheets. The most equatorward of these is consistent with the location of a Region 1 current sheet. Two current sheets were observed in the vicinity of the cusp region, though neither of these were thin current sheets. The fourth current sheet was observed in the mantle region and was largely unaffected by the latitudinal expansion of the cusp region.<br><br><b>Key words. </b>Magnetospheric physics (current systems; energetic particles, precipitating; magnetopause, cusp and boundary layers)
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spelling doaj.art-a2ce4be3af684b1089cb032a8ce06cbc2022-12-22T00:32:49ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762001-09-01191579158710.5194/angeo-19-1579-2001Preliminary two-point observations of the mid-altitude cusp by Cluster PEACE and FGMI. Krauklis0A. N. Fazakerley1C. J. Owen2P. J. Carter3M. W. Dunlop4A. J. Coates5S. Szita6M. G. G. T. Taylor7P. Travnicek8G. Watson9R. J. Wilson10Mullard Space Science Laboratory, Department of Space and Climate Physics, University College London, UKMullard Space Science Laboratory, Department of Space and Climate Physics, University College London, UKMullard Space Science Laboratory, Department of Space and Climate Physics, University College London, UKMullard Space Science Laboratory, Department of Space and Climate Physics, University College London, UKBlackett Laboratory, Imperial College of Science Technology and Medicine, London, UKMullard Space Science Laboratory, Department of Space and Climate Physics, University College London, UKMullard Space Science Laboratory, Department of Space and Climate Physics, University College London, UKMullard Space Science Laboratory, Department of Space and Climate Physics, University College London, UKMullard Space Science Laboratory, Department of Space and Climate Physics, University College London, UKMullard Space Science Laboratory, Department of Space and Climate Physics, University College London, UKMullard Space Science Laboratory, Department of Space and Climate Physics, University College London, UKOn 1 October 2000, Cluster spacecraft Samba (Cluster 3) and Tango (Cluster 4) made an outbound crossing of the northern mid-altitude (4.7 <i>R<sub>E</sub></i>) cusp region, moving roughly parallel to the noon meridian. We present preliminary observations from this interval made by the PEACE and FGM instruments. The interplanetary magnetic field at the magnetopause is estimated to have turned south at the time of our observations, based on ACE data as well as a rough estimate of the time taken for the solar wind to travel between ACE and the magnetopause. Cluster 3 encountered the low-latitude boundary layer (LLBL) between 12:20:30 to 12:26:00 UT, and the cusp region between 12:26:00 and 12:32:30 UT. Cluster 4 encountered the LLBL between 12:22:00 to 12:29:00 UT, and the cusp region between 12:29:00 and 12:38:00 UT. During the interval between the two spacecraft passages through these regions, the open/closed field line boundary was observed to move equatorward by 0.33° invariant latitude, while the latitudinal extent of the cusp region increased by 0.5°. Both of these observations are consistent with the ongoing reconnection at the sub-solar magnetopause. The magnetic field data indicate that Cluster encountered four field-aligned longitudinally extended current sheets. The most equatorward of these is consistent with the location of a Region 1 current sheet. Two current sheets were observed in the vicinity of the cusp region, though neither of these were thin current sheets. The fourth current sheet was observed in the mantle region and was largely unaffected by the latitudinal expansion of the cusp region.<br><br><b>Key words. </b>Magnetospheric physics (current systems; energetic particles, precipitating; magnetopause, cusp and boundary layers)https://www.ann-geophys.net/19/1579/2001/angeo-19-1579-2001.pdf
spellingShingle I. Krauklis
A. N. Fazakerley
C. J. Owen
P. J. Carter
M. W. Dunlop
A. J. Coates
S. Szita
M. G. G. T. Taylor
P. Travnicek
G. Watson
R. J. Wilson
Preliminary two-point observations of the mid-altitude cusp by Cluster PEACE and FGM
Annales Geophysicae
title Preliminary two-point observations of the mid-altitude cusp by Cluster PEACE and FGM
title_full Preliminary two-point observations of the mid-altitude cusp by Cluster PEACE and FGM
title_fullStr Preliminary two-point observations of the mid-altitude cusp by Cluster PEACE and FGM
title_full_unstemmed Preliminary two-point observations of the mid-altitude cusp by Cluster PEACE and FGM
title_short Preliminary two-point observations of the mid-altitude cusp by Cluster PEACE and FGM
title_sort preliminary two point observations of the mid altitude cusp by cluster peace and fgm
url https://www.ann-geophys.net/19/1579/2001/angeo-19-1579-2001.pdf
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