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Propagation and damping of broadband upstream whistlersPrevious studies indicated that damping rates of upstream whistlers strongly depend on the details of the electron distribution function. Moreover, detailed analysis of Doppler-shift and whistler dispersion relation indicated that upstream whistlers propagate obliquely in a broad band. In this paper we present results of a kinetic calculation of damping lengths of wide-band whistlers using the sum of 7-drifting bi-Maxwellian electron distributions as a best fit to the International Sun Earth Explorer (ISEE) 1 electron data. For 2 cases, when upstream whistlers are observed, convective damping lengths derived from ISEE magnetic field and ephemeris data are compared with theoretical results. We find that the calculated convective damping lengths are consistent with the data and that upstream whistlers remain marginally stable. We also show that the slope of plasma frame spectra of upstream whistlers, obtained by direct fitting of the observed spectra is between 5 and 7 with a sharp lower frequency cutoff corresponding to a wavelength of about one ion inertial length. When the solar wind velocity is directed largely along the wave normal of the upstream whistlers the polariztion of the right hand waves becomes reversed and low frequencies are switched to high resulting in a peaked spectrum with a strong high frequency cutoff. The overall spectral, wave and particle characteristics, proximity to the shock as well as propagation and damping properties indicate that these waves cannot be generated locally. Instead the observed upstream whistlers arise in the shock ramp most likely by a variety of cross-field drift and/or anisotropy driven instabilities.
Document ID
19950053623
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Orlowski, D. S.
(University of California, Los Angeles, CA US, United States)
Russell, C. T.
(University of California, Los Angeles, CA US, United States)
Krauss-Varban, D.
(University of California, La Jolla, CA US, United States)
Omidi, N.
(University of California, La Jolla, CA US, United States)
Thomsen, M. F.
(Los Alamos National Laboratory, Los Alamos, NM US, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1995
Publication Information
Publication: Advances in Space Research
Volume: 15
Issue: 8-9
ISSN: 0273-1177
Subject Category
Geophysics
Accession Number
95A85222
Distribution Limits
Public
Copyright
Other

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