Magnetic field configuration and field-aligned acceleration of energetic ions during substorm onsets
In this paper, we present an interpretation of the observed field-aligned acceleration events measured by GEOS-2 near the night-side synchronous orbit at substorm onsets (Chen et al., 2000). We show that field-aligned acceleration of ions (with pitch angle asymmetry) is closely related to st...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2001-09-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/19/1089/2001/angeo-19-1089-2001.pdf |
| _version_ | 1818392808436793344 |
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| author | A. Korth Z. Y. Pu |
| author_facet | A. Korth Z. Y. Pu |
| author_sort | A. Korth |
| collection | DOAJ |
| description | In this paper, we present
an interpretation of the observed field-aligned acceleration events measured by
GEOS-2 near the night-side synchronous orbit at substorm onsets (Chen et al.,
2000). We show that field-aligned acceleration of ions (with pitch angle
asymmetry) is closely related to strong short-lived electric fields in the <i>E<sub>y</sub></i>
direction. The acceleration is associated with either rapid dipolarization or
further stretching of local magnetic field lines. Theoretical analysis suggests
that a centrifugal mechanism is a likely candidate for the parallel
energization. <i>Equatorward</i> or <i>anti-equatorward </i>energization occurs
when the tail current sheet is thinner tailward or earthward of the spacecraft,
respectively. The magnetic field topology leading to <i>anti-equatorward</i>
energization corresponds to a situation where the near-Earth tail undergoes
further compression and the inner edge of the plasma sheet extends inwards as
close as the night-side geosynchronous altitudes.<br><br><b>Key words. </b>Magnetospheric physics (magnetospheric
configuration and dynamics; plasma sheet; storms and sub-storms) |
| first_indexed | 2024-12-14T05:35:18Z |
| format | Article |
| id | doaj.art-f3847606bc9e43948f78eef51f920abf |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-12-14T05:35:18Z |
| publishDate | 2001-09-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-f3847606bc9e43948f78eef51f920abf2022-12-21T23:15:13ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762001-09-01191089109410.5194/angeo-19-1089-2001Magnetic field configuration and field-aligned acceleration of energetic ions during substorm onsetsA. Korth0Z. Y. Pu1Max-Planck-Institut für Aeronomie, D-37191 Katlenburg-Lindau, GermanySpace Weather Laboratory, Center for Space Science and Application Research, Chinese Academy of Science, Beijing, China and Department of Geophysics, Peking University, Beijing, ChinaIn this paper, we present an interpretation of the observed field-aligned acceleration events measured by GEOS-2 near the night-side synchronous orbit at substorm onsets (Chen et al., 2000). We show that field-aligned acceleration of ions (with pitch angle asymmetry) is closely related to strong short-lived electric fields in the <i>E<sub>y</sub></i> direction. The acceleration is associated with either rapid dipolarization or further stretching of local magnetic field lines. Theoretical analysis suggests that a centrifugal mechanism is a likely candidate for the parallel energization. <i>Equatorward</i> or <i>anti-equatorward </i>energization occurs when the tail current sheet is thinner tailward or earthward of the spacecraft, respectively. The magnetic field topology leading to <i>anti-equatorward</i> energization corresponds to a situation where the near-Earth tail undergoes further compression and the inner edge of the plasma sheet extends inwards as close as the night-side geosynchronous altitudes.<br><br><b>Key words. </b>Magnetospheric physics (magnetospheric configuration and dynamics; plasma sheet; storms and sub-storms)https://www.ann-geophys.net/19/1089/2001/angeo-19-1089-2001.pdf |
| spellingShingle | A. Korth Z. Y. Pu Magnetic field configuration and field-aligned acceleration of energetic ions during substorm onsets Annales Geophysicae |
| title | Magnetic field configuration and field-aligned acceleration of energetic ions during substorm onsets |
| title_full | Magnetic field configuration and field-aligned acceleration of energetic ions during substorm onsets |
| title_fullStr | Magnetic field configuration and field-aligned acceleration of energetic ions during substorm onsets |
| title_full_unstemmed | Magnetic field configuration and field-aligned acceleration of energetic ions during substorm onsets |
| title_short | Magnetic field configuration and field-aligned acceleration of energetic ions during substorm onsets |
| title_sort | magnetic field configuration and field aligned acceleration of energetic ions during substorm onsets |
| url | https://www.ann-geophys.net/19/1089/2001/angeo-19-1089-2001.pdf |
| work_keys_str_mv | AT akorth magneticfieldconfigurationandfieldalignedaccelerationofenergeticionsduringsubstormonsets AT zypu magneticfieldconfigurationandfieldalignedaccelerationofenergeticionsduringsubstormonsets |