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The auroral plasma cavity
Author(s) -
Calvert W.
Publication year - 1981
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/gl008i008p00919
Subject(s) - physics , plasma , latitude , cyclotron , magnetic field , ionosphere , radiation , altitude (triangle) , magnetosphere , astrophysics , atomic physics , geophysics , atmospheric sciences , computational physics , astronomy , optics , nuclear physics , geometry , mathematics , quantum mechanics
A region of diminished plasma density has been found to occur at the source of auroral kilometric radiation (AKR). The density within this auroral plasma cavity, determined from limited Hawkeye wave data, was less than 1 cm −3 from 1.8 R E to 3 R E geocentric, at 70° ± 3° invariant magnetic latitude. The altitude variation of the magnetic field produces a minimum in the ratio of plasma frequency to cyclotron frequency within the cavity which accounts for the observed spectrum of AKR.