Wind observations of low energy particles within a solar wind reconnection region
We report characteristics of thermal particle observations during the encounter of the Wind satellite with the separatrix and the outflow domains of a reconnection event on 22 July 1999 in the solar wind. During the studied event the electrostatic analyzers on Wind were transmitting three-dimens...
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doaj-4d0e93df072e45538eec487e1d8eeacb2020-11-25T00:02:52ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762008-09-01262701271010.5194/angeo-26-2701-2008Wind observations of low energy particles within a solar wind reconnection regionK. E. J. Huttunen0K. E. J. Huttunen1S. D. Bale2S. D. Bale3C. Salem4Space Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720, USADepartment of Physics, P.O. Box 64, 00014, Univeristy of Helsinki, FinlandSpace Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720, USADepartment of Physics, University of California, Berkeley, CA 94720, USASpace Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720, USAWe report characteristics of thermal particle observations during the encounter of the Wind satellite with the separatrix and the outflow domains of a reconnection event on 22 July 1999 in the solar wind. During the studied event the electrostatic analyzers on Wind were transmitting three-dimensional electron and proton distributions in a burst mode every 3 s, the spin period of the spacecraft. The event was associated with a magnetic shear angle of 114° and a large guide magnetic field. The observations suggest that Wind crossed the separatrix and outflow regions about a thousand of ion skin depths from the X-line. At the leading separator boundary, a strong proton beam was identified that originated from the direction of the X-line. In the separatrix and the outflow regions, the phase space distributions of thermal electrons displayed field aligned bidirectional anisotropy. During the crossings of the current sheets bounding the outflow region, we identified two adjacent layers in which the dominant thermal electron flows were towards the X-line at the inner edges of the current sheets and away from the X-line at the outer edges. Interestingly, simulation studies and observations in the Earth's magnetosphere have revealed that the electron flows are reversed, consistent with the Hall current system.https://www.ann-geophys.net/26/2701/2008/angeo-26-2701-2008.pdf |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
K. E. J. Huttunen K. E. J. Huttunen S. D. Bale S. D. Bale C. Salem |
spellingShingle |
K. E. J. Huttunen K. E. J. Huttunen S. D. Bale S. D. Bale C. Salem Wind observations of low energy particles within a solar wind reconnection region Annales Geophysicae |
author_facet |
K. E. J. Huttunen K. E. J. Huttunen S. D. Bale S. D. Bale C. Salem |
author_sort |
K. E. J. Huttunen |
title |
Wind observations of low energy particles within a solar wind reconnection region |
title_short |
Wind observations of low energy particles within a solar wind reconnection region |
title_full |
Wind observations of low energy particles within a solar wind reconnection region |
title_fullStr |
Wind observations of low energy particles within a solar wind reconnection region |
title_full_unstemmed |
Wind observations of low energy particles within a solar wind reconnection region |
title_sort |
wind observations of low energy particles within a solar wind reconnection region |
publisher |
Copernicus Publications |
series |
Annales Geophysicae |
issn |
0992-7689 1432-0576 |
publishDate |
2008-09-01 |
description |
We report characteristics of thermal particle observations during the
encounter of the Wind satellite with the separatrix and the outflow domains
of a reconnection event on 22 July 1999 in the solar wind. During the
studied event the electrostatic analyzers on Wind were transmitting
three-dimensional electron and proton distributions in a burst mode every 3 s,
the spin period of the spacecraft. The event was associated with a
magnetic shear angle of 114° and a large guide magnetic field. The
observations suggest that Wind crossed the separatrix and outflow regions
about a thousand of ion skin depths from the X-line. At the leading separator
boundary, a strong proton beam was identified that originated from the
direction of the X-line. In the separatrix and the outflow regions, the phase
space distributions of thermal electrons displayed field aligned
bidirectional anisotropy. During the crossings of the current sheets bounding
the outflow region, we identified two adjacent layers in which the dominant
thermal electron flows were towards the X-line at the inner edges of the
current sheets and away from the X-line at the outer edges. Interestingly,
simulation studies and observations in the Earth's magnetosphere have
revealed that the electron flows are reversed, consistent with the Hall
current system. |
url |
https://www.ann-geophys.net/26/2701/2008/angeo-26-2701-2008.pdf |
work_keys_str_mv |
AT kejhuttunen windobservationsoflowenergyparticleswithinasolarwindreconnectionregion AT kejhuttunen windobservationsoflowenergyparticleswithinasolarwindreconnectionregion AT sdbale windobservationsoflowenergyparticleswithinasolarwindreconnectionregion AT sdbale windobservationsoflowenergyparticleswithinasolarwindreconnectionregion AT csalem windobservationsoflowenergyparticleswithinasolarwindreconnectionregion |
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