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FAST satellite observations of large‐amplitude solitary structures
Author(s) -
Ergun R. E.,
Carlson C. W.,
McFadden J. P.,
Mozer F. S.,
Delory G. T.,
Peria W.,
Chaston C. C.,
Temerin M.,
Roth I.,
Muschietti L.,
Elphic R.,
Strangeway R.,
Pfaff R.,
Cattell C. A.,
Klumpar D.,
Shelley E.,
Peterson W.,
Moebius E.,
Kistler L.
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/98gl00636
Subject(s) - amplitude , physics , electric field , electron , geophysics , magnetic field , satellite , computational physics , optics , astronomy , quantum mechanics
We report observations of “fast solitary waves” that are ubiquitous in downward current regions of the mid‐altitude auroral zone. The single‐period structures have large amplitudes (up to 2.5 V/m), travel much faster than the ion acoustic speed, carry substantial potentials (up to ∼100 Volts), and are associated with strong modulations of energetic electron fluxes. The amplitude and speed of the structures distinguishes them from ion‐acoustic solitary waves or weak double layers. The electromagnetic signature appears to be that of an positive charge (electron hole) traveling anti‐earthward. We present evidence that the structures are in or near regions of magnetic‐field‐aligned electric fields and propose that these nonlinear structures play a key role in supporting parallel electric fields in the downward current region of the auroral zone.