Dayside auroral activity and magnetic flux transfer from the solar wind
Combined observations by meridian-scanning photometers and the EISCAT radar show that the "midday-auroral breakup" phenomenon is associated with major increases in ionospheric flow. A sequence of nine events is observed in the early afternoon MLT sector during a period when the IMF is stro...
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American Geophysical Union
1989
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Online Access: | https://centaur.reading.ac.uk/38883/ https://centaur.reading.ac.uk/38883/1/49_Lockwoodetal_1989.pdf https://doi.org/10.1029/GL016i001p00033 |
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ftunivreading:oai:centaur.reading.ac.uk:38883 2024-09-15T18:04:29+00:00 Dayside auroral activity and magnetic flux transfer from the solar wind Lockwood, Mike Sandholt, P. E. Cowley, S. W. H. 1989 text https://centaur.reading.ac.uk/38883/ https://centaur.reading.ac.uk/38883/1/49_Lockwoodetal_1989.pdf https://doi.org/10.1029/GL016i001p00033 en eng American Geophysical Union https://centaur.reading.ac.uk/38883/1/49_Lockwoodetal_1989.pdf Lockwood, M. <https://centaur.reading.ac.uk/view/creators/90001127.html> orcid:0000-0002-7397-2172 , Sandholt, P. E. and Cowley, S. W. H. (1989) Dayside auroral activity and magnetic flux transfer from the solar wind. Geophysical Research Letters, 16 (1). pp. 33-36. ISSN 0094-8276 doi: https://doi.org/10.1029/GL016i001p00033 <https://doi.org/10.1029/GL016i001p00033> Article PeerReviewed 1989 ftunivreading https://doi.org/10.1029/GL016i001p00033 2024-06-25T14:57:10Z Combined observations by meridian-scanning photometers and the EISCAT radar show that the "midday-auroral breakup" phenomenon is associated with major increases in ionospheric flow. A sequence of nine events is observed in the early afternoon MLT sector during a period when the IMF is strongly southward with a large positive By component. Each auroral structure is seen at both 630 and 557.7nm and initially moves westward, accompanied by an increase in potential of 30-60kV across the north-south dimension of the EISCAT field-of-view. After a few minutes the arc (or arc fragment) moves into the polar cap and fades, and the velocities observed by the radar swing from westward toward northward. We conclude that dayside auroral breakup is closely associated with momentum transfer across the magnetopause which occurs in a series of events 5-15 minutes apart. The largest of the observed events has dimensions of about 300km (in the direction of westward motion) by 700km, is bounded on its poleward edge by a 5kR arc and is associated with a potential of at least 80kV. Article in Journal/Newspaper EISCAT CentAUR: Central Archive at the University of Reading Geophysical Research Letters 16 1 33 36 |
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Open Polar |
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CentAUR: Central Archive at the University of Reading |
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ftunivreading |
language |
English |
description |
Combined observations by meridian-scanning photometers and the EISCAT radar show that the "midday-auroral breakup" phenomenon is associated with major increases in ionospheric flow. A sequence of nine events is observed in the early afternoon MLT sector during a period when the IMF is strongly southward with a large positive By component. Each auroral structure is seen at both 630 and 557.7nm and initially moves westward, accompanied by an increase in potential of 30-60kV across the north-south dimension of the EISCAT field-of-view. After a few minutes the arc (or arc fragment) moves into the polar cap and fades, and the velocities observed by the radar swing from westward toward northward. We conclude that dayside auroral breakup is closely associated with momentum transfer across the magnetopause which occurs in a series of events 5-15 minutes apart. The largest of the observed events has dimensions of about 300km (in the direction of westward motion) by 700km, is bounded on its poleward edge by a 5kR arc and is associated with a potential of at least 80kV. |
format |
Article in Journal/Newspaper |
author |
Lockwood, Mike Sandholt, P. E. Cowley, S. W. H. |
spellingShingle |
Lockwood, Mike Sandholt, P. E. Cowley, S. W. H. Dayside auroral activity and magnetic flux transfer from the solar wind |
author_facet |
Lockwood, Mike Sandholt, P. E. Cowley, S. W. H. |
author_sort |
Lockwood, Mike |
title |
Dayside auroral activity and magnetic flux transfer from the solar wind |
title_short |
Dayside auroral activity and magnetic flux transfer from the solar wind |
title_full |
Dayside auroral activity and magnetic flux transfer from the solar wind |
title_fullStr |
Dayside auroral activity and magnetic flux transfer from the solar wind |
title_full_unstemmed |
Dayside auroral activity and magnetic flux transfer from the solar wind |
title_sort |
dayside auroral activity and magnetic flux transfer from the solar wind |
publisher |
American Geophysical Union |
publishDate |
1989 |
url |
https://centaur.reading.ac.uk/38883/ https://centaur.reading.ac.uk/38883/1/49_Lockwoodetal_1989.pdf https://doi.org/10.1029/GL016i001p00033 |
genre |
EISCAT |
genre_facet |
EISCAT |
op_relation |
https://centaur.reading.ac.uk/38883/1/49_Lockwoodetal_1989.pdf Lockwood, M. <https://centaur.reading.ac.uk/view/creators/90001127.html> orcid:0000-0002-7397-2172 , Sandholt, P. E. and Cowley, S. W. H. (1989) Dayside auroral activity and magnetic flux transfer from the solar wind. Geophysical Research Letters, 16 (1). pp. 33-36. ISSN 0094-8276 doi: https://doi.org/10.1029/GL016i001p00033 <https://doi.org/10.1029/GL016i001p00033> |
op_doi |
https://doi.org/10.1029/GL016i001p00033 |
container_title |
Geophysical Research Letters |
container_volume |
16 |
container_issue |
1 |
container_start_page |
33 |
op_container_end_page |
36 |
_version_ |
1810441974534111232 |