Location and characteristics of the reconnection X line deduced from low-altitude satellite and ground-based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data
We present an analysis of a cusp ion step, observed by the Defense Meteorological Satellite Program (DMSP) F10 spacecraft, between two poleward moving events of enhanced ionospheric electron temperature, observed by the European Incoherent Scatter (EISCAT) radar. From the ions detected by the satell...
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American Geophysical Union
1995
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Online Access: | https://centaur.reading.ac.uk/38797/ https://centaur.reading.ac.uk/38797/1/131_Lockwood_95JA01339.pdf https://doi.org/10.1029/95JA01339 |
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ftunivreading:oai:centaur.reading.ac.uk:38797 2024-02-11T10:03:29+01:00 Location and characteristics of the reconnection X line deduced from low-altitude satellite and ground-based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data Lockwood, Mike Davis, Chris J. Smith, M. F. Onsager, T. G. Denig, W. F. 1995 text https://centaur.reading.ac.uk/38797/ https://centaur.reading.ac.uk/38797/1/131_Lockwood_95JA01339.pdf https://doi.org/10.1029/95JA01339 en eng American Geophysical Union https://centaur.reading.ac.uk/38797/1/131_Lockwood_95JA01339.pdf Lockwood, M. <https://centaur.reading.ac.uk/view/creators/90001127.html> orcid:0000-0002-7397-2172 , Davis, C. J. <https://centaur.reading.ac.uk/view/creators/90003900.html> orcid:0000-0001-6411-5649 , Smith, M. F., Onsager, T. G. and Denig, W. F. (1995) Location and characteristics of the reconnection X line deduced from low-altitude satellite and ground-based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data. Journal of Geophysical Research, 100 (A11). p. 21803. ISSN 0148-0227 doi: https://doi.org/10.1029/95JA01339 <https://doi.org/10.1029/95JA01339> Article PeerReviewed 1995 ftunivreading https://doi.org/10.1029/95JA01339 2024-01-25T23:59:31Z We present an analysis of a cusp ion step, observed by the Defense Meteorological Satellite Program (DMSP) F10 spacecraft, between two poleward moving events of enhanced ionospheric electron temperature, observed by the European Incoherent Scatter (EISCAT) radar. From the ions detected by the satellite, the variation of the reconnection rate is computed for assumed distances along the open-closed field line separatrix from the satellite to the X line, do. Comparison with the onset times of the associated ionospheric events allows this distance to be estimated, but with an uncertainty due to the determination of the low-energy cutoff of the ion velocity distribution function, ƒ(ν). Nevertheless, the reconnection site is shown to be on the dayside magnetopause, consistent with the reconnection model of the cusp during southward interplanetary magnetic field (IMF). Analysis of the time series of distribution function at constant energies, ƒ(ts), shows that the best estimate of the distance do is 14.5±2 RE. This is consistent with various magnetopause observations of the signatures of reconnection for southward IMF. The ion precipitation is used to reconstruct the field-parallel part of the Cowley D ion distribution function injected into the open low-latitude boundary layer in the vicinity of the X line. From this reconstruction, the field-aligned component of the magnetosheath flow is found to be only −55±65 km s−1 near the X line, which means either that the reconnection X line is near the stagnation region at the nose of the magnetosphere, or that it is closely aligned with the magnetosheath flow streamline which is orthogonal to the magnetosheath field, or both. In addition, the sheath Alfvén speed at the X line is found to be 220±45 km s−1, and the speed with which newly opened field lines are ejected from the X line is 165±30 km s−1. We show that the inferred magnetic field, plasma density, and temperature of the sheath near the X line are consistent with a near-subsolar reconnection site and confirm that the ... Article in Journal/Newspaper EISCAT CentAUR: Central Archive at the University of Reading Cowley ENVELOPE(-134.909,-134.909,60.518,60.518) Journal of Geophysical Research: Space Physics 100 A11 21803 21813 |
institution |
Open Polar |
collection |
CentAUR: Central Archive at the University of Reading |
op_collection_id |
ftunivreading |
language |
English |
description |
We present an analysis of a cusp ion step, observed by the Defense Meteorological Satellite Program (DMSP) F10 spacecraft, between two poleward moving events of enhanced ionospheric electron temperature, observed by the European Incoherent Scatter (EISCAT) radar. From the ions detected by the satellite, the variation of the reconnection rate is computed for assumed distances along the open-closed field line separatrix from the satellite to the X line, do. Comparison with the onset times of the associated ionospheric events allows this distance to be estimated, but with an uncertainty due to the determination of the low-energy cutoff of the ion velocity distribution function, ƒ(ν). Nevertheless, the reconnection site is shown to be on the dayside magnetopause, consistent with the reconnection model of the cusp during southward interplanetary magnetic field (IMF). Analysis of the time series of distribution function at constant energies, ƒ(ts), shows that the best estimate of the distance do is 14.5±2 RE. This is consistent with various magnetopause observations of the signatures of reconnection for southward IMF. The ion precipitation is used to reconstruct the field-parallel part of the Cowley D ion distribution function injected into the open low-latitude boundary layer in the vicinity of the X line. From this reconstruction, the field-aligned component of the magnetosheath flow is found to be only −55±65 km s−1 near the X line, which means either that the reconnection X line is near the stagnation region at the nose of the magnetosphere, or that it is closely aligned with the magnetosheath flow streamline which is orthogonal to the magnetosheath field, or both. In addition, the sheath Alfvén speed at the X line is found to be 220±45 km s−1, and the speed with which newly opened field lines are ejected from the X line is 165±30 km s−1. We show that the inferred magnetic field, plasma density, and temperature of the sheath near the X line are consistent with a near-subsolar reconnection site and confirm that the ... |
format |
Article in Journal/Newspaper |
author |
Lockwood, Mike Davis, Chris J. Smith, M. F. Onsager, T. G. Denig, W. F. |
spellingShingle |
Lockwood, Mike Davis, Chris J. Smith, M. F. Onsager, T. G. Denig, W. F. Location and characteristics of the reconnection X line deduced from low-altitude satellite and ground-based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data |
author_facet |
Lockwood, Mike Davis, Chris J. Smith, M. F. Onsager, T. G. Denig, W. F. |
author_sort |
Lockwood, Mike |
title |
Location and characteristics of the reconnection X line deduced from low-altitude satellite and ground-based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data |
title_short |
Location and characteristics of the reconnection X line deduced from low-altitude satellite and ground-based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data |
title_full |
Location and characteristics of the reconnection X line deduced from low-altitude satellite and ground-based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data |
title_fullStr |
Location and characteristics of the reconnection X line deduced from low-altitude satellite and ground-based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data |
title_full_unstemmed |
Location and characteristics of the reconnection X line deduced from low-altitude satellite and ground-based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data |
title_sort |
location and characteristics of the reconnection x line deduced from low-altitude satellite and ground-based observations: 2. defense meteorological satellite program and european incoherent scatter data |
publisher |
American Geophysical Union |
publishDate |
1995 |
url |
https://centaur.reading.ac.uk/38797/ https://centaur.reading.ac.uk/38797/1/131_Lockwood_95JA01339.pdf https://doi.org/10.1029/95JA01339 |
long_lat |
ENVELOPE(-134.909,-134.909,60.518,60.518) |
geographic |
Cowley |
geographic_facet |
Cowley |
genre |
EISCAT |
genre_facet |
EISCAT |
op_relation |
https://centaur.reading.ac.uk/38797/1/131_Lockwood_95JA01339.pdf Lockwood, M. <https://centaur.reading.ac.uk/view/creators/90001127.html> orcid:0000-0002-7397-2172 , Davis, C. J. <https://centaur.reading.ac.uk/view/creators/90003900.html> orcid:0000-0001-6411-5649 , Smith, M. F., Onsager, T. G. and Denig, W. F. (1995) Location and characteristics of the reconnection X line deduced from low-altitude satellite and ground-based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data. Journal of Geophysical Research, 100 (A11). p. 21803. ISSN 0148-0227 doi: https://doi.org/10.1029/95JA01339 <https://doi.org/10.1029/95JA01339> |
op_doi |
https://doi.org/10.1029/95JA01339 |
container_title |
Journal of Geophysical Research: Space Physics |
container_volume |
100 |
container_issue |
A11 |
container_start_page |
21803 |
op_container_end_page |
21813 |
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