Flow-aligned jets in the magnetospheric cusp: Results from the Geospace Environment Modeling Pilot Program
The extended flight of the Airborne Ionospheric Observatory during the Geospace Environment Modeling (GEM) Pilot program on January 16, 1990, allowed continuous all-sky monitoring of the two-dimensional ionospheric footprint of the northward interplanetary magnetic field (IMF) cusp in several wavele...
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Online Access: | https://centaur.reading.ac.uk/38806/ https://centaur.reading.ac.uk/38806/1/122_Weissetal_94JA03360.pdf https://doi.org/10.1029/94JA03360 |
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ftunivreading:oai:centaur.reading.ac.uk:38806 2024-06-23T07:52:27+00:00 Flow-aligned jets in the magnetospheric cusp: Results from the Geospace Environment Modeling Pilot Program Weiss, L. A. Reiff, P. H. Weber, E. J. Carlson, H. C. Lockwood, Mike Peterson, W. K. 1995 text https://centaur.reading.ac.uk/38806/ https://centaur.reading.ac.uk/38806/1/122_Weissetal_94JA03360.pdf https://doi.org/10.1029/94JA03360 en eng https://centaur.reading.ac.uk/38806/1/122_Weissetal_94JA03360.pdf Weiss, L. A., Reiff, P. H., Weber, E. J., Carlson, H. C., Lockwood, M. <https://centaur.reading.ac.uk/view/creators/90001127.html> orcid:0000-0002-7397-2172 and Peterson, W. K. (1995) Flow-aligned jets in the magnetospheric cusp: Results from the Geospace Environment Modeling Pilot Program. Journal of Geophysical Research, 100 (A5). p. 7649. ISSN 0148-0227 doi: https://doi.org/10.1029/94JA03360 <https://doi.org/10.1029/94JA03360> Article PeerReviewed 1995 ftunivreading https://doi.org/10.1029/94JA03360 2024-06-11T15:02:59Z The extended flight of the Airborne Ionospheric Observatory during the Geospace Environment Modeling (GEM) Pilot program on January 16, 1990, allowed continuous all-sky monitoring of the two-dimensional ionospheric footprint of the northward interplanetary magnetic field (IMF) cusp in several wavelengths. Especially important in determining the locus of magnetosheath electron precipitation was the 630.0-nm red line emission. The most striking morphological change in the images was the transient appearance of zonally elongated regions of enhanced 630.0-nm emission which resembled “rays” emanating from the centroid of the precipitation. The appearance of these rays was strongly correlated with the Y component of the IMF: when the magnitude of By was large compared to Bz, the rays appeared; otherwise, the distribution was relatively unstructured. Late in the flight the field of view of the imager included the field of view of flow measurements from the European incoherent scatter radar (EISCAT). The rays visible in 630.0-nm emission exactly aligned with the position of strong flow jets observed by EISCAT. We attribute this correspondence to the requirement of quasi-neutrality; namely, the soft electrons have their largest precipitating fluxes where the bulk of the ions precipitate. The ions, in regions of strong convective flow, are spread out farther along the flow path than in regions of weaker flow. The occurrence and direction of these flow bursts are controlled by the IMF in a manner consistent with newly opened flux tubes; i.e., when |By| > |Bz|, tension in the reconnected field lines produce east-west flow regions downstream of the ionospheric projection of the x line. We interpret the optical rays (flow bursts), which typically last between 5 and 15 min, as evidence of periods of enhanced dayside (or lobe) reconnection when |By| > |Bz|. The length of the reconnection pulse is difficult to determine, however, since strong zonal flows would be expected to persist until the tension force in the field ... Article in Journal/Newspaper EISCAT CentAUR: Central Archive at the University of Reading The ''Y'' ENVELOPE(-112.453,-112.453,57.591,57.591) Journal of Geophysical Research 100 A5 7649 |
institution |
Open Polar |
collection |
CentAUR: Central Archive at the University of Reading |
op_collection_id |
ftunivreading |
language |
English |
description |
The extended flight of the Airborne Ionospheric Observatory during the Geospace Environment Modeling (GEM) Pilot program on January 16, 1990, allowed continuous all-sky monitoring of the two-dimensional ionospheric footprint of the northward interplanetary magnetic field (IMF) cusp in several wavelengths. Especially important in determining the locus of magnetosheath electron precipitation was the 630.0-nm red line emission. The most striking morphological change in the images was the transient appearance of zonally elongated regions of enhanced 630.0-nm emission which resembled “rays” emanating from the centroid of the precipitation. The appearance of these rays was strongly correlated with the Y component of the IMF: when the magnitude of By was large compared to Bz, the rays appeared; otherwise, the distribution was relatively unstructured. Late in the flight the field of view of the imager included the field of view of flow measurements from the European incoherent scatter radar (EISCAT). The rays visible in 630.0-nm emission exactly aligned with the position of strong flow jets observed by EISCAT. We attribute this correspondence to the requirement of quasi-neutrality; namely, the soft electrons have their largest precipitating fluxes where the bulk of the ions precipitate. The ions, in regions of strong convective flow, are spread out farther along the flow path than in regions of weaker flow. The occurrence and direction of these flow bursts are controlled by the IMF in a manner consistent with newly opened flux tubes; i.e., when |By| > |Bz|, tension in the reconnected field lines produce east-west flow regions downstream of the ionospheric projection of the x line. We interpret the optical rays (flow bursts), which typically last between 5 and 15 min, as evidence of periods of enhanced dayside (or lobe) reconnection when |By| > |Bz|. The length of the reconnection pulse is difficult to determine, however, since strong zonal flows would be expected to persist until the tension force in the field ... |
format |
Article in Journal/Newspaper |
author |
Weiss, L. A. Reiff, P. H. Weber, E. J. Carlson, H. C. Lockwood, Mike Peterson, W. K. |
spellingShingle |
Weiss, L. A. Reiff, P. H. Weber, E. J. Carlson, H. C. Lockwood, Mike Peterson, W. K. Flow-aligned jets in the magnetospheric cusp: Results from the Geospace Environment Modeling Pilot Program |
author_facet |
Weiss, L. A. Reiff, P. H. Weber, E. J. Carlson, H. C. Lockwood, Mike Peterson, W. K. |
author_sort |
Weiss, L. A. |
title |
Flow-aligned jets in the magnetospheric cusp: Results from the Geospace Environment Modeling Pilot Program |
title_short |
Flow-aligned jets in the magnetospheric cusp: Results from the Geospace Environment Modeling Pilot Program |
title_full |
Flow-aligned jets in the magnetospheric cusp: Results from the Geospace Environment Modeling Pilot Program |
title_fullStr |
Flow-aligned jets in the magnetospheric cusp: Results from the Geospace Environment Modeling Pilot Program |
title_full_unstemmed |
Flow-aligned jets in the magnetospheric cusp: Results from the Geospace Environment Modeling Pilot Program |
title_sort |
flow-aligned jets in the magnetospheric cusp: results from the geospace environment modeling pilot program |
publishDate |
1995 |
url |
https://centaur.reading.ac.uk/38806/ https://centaur.reading.ac.uk/38806/1/122_Weissetal_94JA03360.pdf https://doi.org/10.1029/94JA03360 |
long_lat |
ENVELOPE(-112.453,-112.453,57.591,57.591) |
geographic |
The ''Y'' |
geographic_facet |
The ''Y'' |
genre |
EISCAT |
genre_facet |
EISCAT |
op_relation |
https://centaur.reading.ac.uk/38806/1/122_Weissetal_94JA03360.pdf Weiss, L. A., Reiff, P. H., Weber, E. J., Carlson, H. C., Lockwood, M. <https://centaur.reading.ac.uk/view/creators/90001127.html> orcid:0000-0002-7397-2172 and Peterson, W. K. (1995) Flow-aligned jets in the magnetospheric cusp: Results from the Geospace Environment Modeling Pilot Program. Journal of Geophysical Research, 100 (A5). p. 7649. ISSN 0148-0227 doi: https://doi.org/10.1029/94JA03360 <https://doi.org/10.1029/94JA03360> |
op_doi |
https://doi.org/10.1029/94JA03360 |
container_title |
Journal of Geophysical Research |
container_volume |
100 |
container_issue |
A5 |
container_start_page |
7649 |
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1802643761569726464 |