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| Titel |
Solitary potential structures observed in the magnetosheath by the Cluster spacecraft |
| VerfasserIn |
J. S. Pickett, J. D. Menietti, D. A. Gurnett, B. Tsurutani, P. M. Kintner, E. Klatt, A. Balogh |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1023-5809
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| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics ; 10, no. 1/2 ; Nr. 10, no. 1/2, S.3-11 |
| Datensatznummer |
250007815
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| Publikation (Nr.) |
 copernicus.org/npg-10-3-2003.pdf |
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| Zusammenfassung |
| Bipolar pulses of ~
25-100 µs in duration have been observed in the wave electric field
data obtained by the Wideband plasma wave instrument on the Cluster
spacecraft in the dayside magnetosheath. These pulses are similar in
almost all respects to those observed on several spacecraft over the last
few years. They represent solitary potential structures, and in this case,
electron phase space holes. When the time series data containing the
bipolar pulses on Cluster are transformed to the frequency domain by a
windowed FFT, the pulses appear as typical broad-band features, extending
from the low-frequency cutoff of the bandpass filter, ~ 1 kHz, up to as
great as 20-40 kHz in some cases, with decreasing intensity as the
frequency increases. The upper frequency cutoff of the broad band is an
indication of the individual pulse durations (1/f). The solitary potential
structures are detected when the local magnetic field is contained
primarily in the spin plane, indicating that they propagate along the
magnetic field. Their frequency extent and intensity seem to increase as
the angle between the directions of the magnetic field and the plasma flow
decreases from 90°. Of major significance is the finding that the overall
profile of the broad-band features observed simultaneously by two Cluster
spacecraft, separated by a distance of over 750 km, are strikingly similar
in terms of onset times, frequency extent, intensity, and termination.
This implies that the generation region of the solitary potential
structures observed in the magnetosheath near the bow shock is very large
and may be located at or near the bow shock, or be connected with the bow
shock in some way. |
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