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A new interpretation on the origin of enhanced ion acoustic fluctuations in the upper ionosphere
Author(s) -
Forme F. R. E.
Publication year - 1993
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 - 10.1029/93gl02490
Subject(s) - ionosphere , physics , rocket (weapon) , ion acoustic wave , ion , electron , instability , acoustic wave , beam (structure) , computational physics , atomic physics , incoherent scatter , langmuir probe , geophysics , optics , plasma diagnostics , mechanics , nuclear physics , quantum mechanics , engineering , aerospace engineering
Enhanced ion acoustic fluctuations have been recently observed by incoherent scatter radars in the upper ionosphere. Here it is suggested that these fluctuations can be due to the Langmuir wave decay L→L’+S. In this process the “pump” Langmuir waves (L) are produced by a beam instability due to streaming soft electrons. Those waves then produce backscattered Langmuir waves (L’) and ion acoustic waves (S). Estimations of the required electron beam energy and flux, as well as the beam number density are given. It is found that satellite and rocket observations support this interpretation.