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| Titel |
Electrostatic solitary waves in current layers: from Cluster observations during a super-substorm to beam experiments at the LAPD |
| VerfasserIn |
J. S. Pickett, L.-J. Chen, O. Santolík, S. Grimald, B. Lavraud, O. P. Verkhoglyadova, B. T. Tsurutani, B. Lefebvre, A. Fazakerley, G. S. Lakhina, S. S. Ghosh, B. Grison, P. M. E. Décréau, D. A. Gurnett, R. Torbert, N. Cornilleau-Wehrlin, I. Dandouras, E. Lucek |
| 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 ; 16, no. 3 ; Nr. 16, no. 3 (2009-06-25), S.431-442 |
| Datensatznummer |
250013193
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| Publikation (Nr.) |
 copernicus.org/npg-16-431-2009.pdf |
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| Zusammenfassung |
| Electrostatic Solitary Waves (ESWs) have been observed by several spacecraft
in the current layers of Earth's magnetosphere since 1982. ESWs are
manifested as isolated pulses (one wave period) in the high time resolution
waveform data obtained on these spacecraft. They are thus nonlinear
structures generated out of nonlinear instabilities and processes. We report
the first observations of ESWs associated with the onset of a super-substorm
that occurred on 24 August 2005 while the Cluster spacecraft were located in
the magnetotail at around 18–19 RE and moving northward from the plasma
sheet to the lobes. These ESWs were detected in the waveform data of the WBD
plasma wave receiver on three of the Cluster spacecraft. The majority of the
ESWs were detected about 5 min after the super-substorm onset during
which time 1) the PEACE electron instrument detected significant
field-aligned electron fluxes from a few 100 eV to 3.5 keV, 2) the EDI
instrument detected bursts of field-aligned electron currents, 3) the FGM
instrument detected substantial magnetic fluctuations and the presence of
Alfvén waves, 4) the STAFF experiment detected broadband electric and
magnetic waves, ion cyclotron waves and whistler mode waves, and 5) CIS
detected nearly comparable densities of H+ and O+ ions and a large tailward
H+ velocity. We compare the characteristics of the ESWs observed during this
event to those created in the laboratory at the University of California-Los
Angeles Plasma Device (LAPD) with an electron beam. We find that the
time durations of both space and LAPD ESWs are only slightly larger than the
respective local electron plasma periods, indicating that electron, and not
ion, dynamics are responsible for generation of the ESWs. We have discussed
possible mechanisms for generating the ESWs in space, including the beam and
kinetic Buneman type instabilities and the acoustic instabilities. Future
studies will examine these mechanisms in more detail using the space
measurements as inputs to models, and better relate the ESW space
measurements to the laboratory through PIC code models. |
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