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Titel |
Magnetic field turbulence, electron heating, magnetic holes, proton cyclotron waves, and the onsets of bipolar pulse (electron hole) events: a possible unifying scenario |
VerfasserIn |
B. T. Tsurutani, B. Dasgupta, J. K. Arballo, G. S. Lakhina, J. S. Pickett |
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.27-35 |
Datensatznummer |
250007817
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Publikation (Nr.) |
copernicus.org/npg-10-27-2003.pdf |
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Zusammenfassung |
Two electron heating
events have been identified on 20 May 1996 when Polar was in the polar
cap/polar cusp boundary layer. The electron heating events were located
within magnetic holes/cavities/bubbles and were accompanied by nonlinear
± 14 nT peak-to-peak (f ~ 0.6 to 0.7 fcp) obliquely
propagating proton cyclotron waves. The electrons appear to be heated
isotropically. Electric bipolar pulse (electron hole) onset events were
also detected within the heating events. We propose a scenario which can
link the above phenomena. Nonlinear Alfvén waves, generated through cusp
magnetic reconnection, propagate down magnetic field lines and locally
heat electrons through the ponderomotive force. The magnetic cavity is
created through the diamagnetic effect of the heated electrons. Ion
heating also occurs through ponderomotive acceleration (but much less than
the electrons) and the protons generate the electromagnetic proton
cyclotron waves through the loss cone instability. The obliquely
propagating electromagnetic proton cyclotron waves accelerate bi-streaming
electrons, which are the source of free energy for the electron holes. |
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