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Magnetosonic waves adjacent to the plasma sheet in the distant magnetotail: ISEE‐3
Author(s) -
Tsurutani Bruce T.,
Smith Edward J.
Publication year - 1984
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/gl011i004p00331
Subject(s) - physics , substorm , plasma sheet , plasma , cyclotron , amplitude , instability , current sheet , proton , adiabatic process , magnetic field , longitudinal wave , magnetosphere , wavelength , computational physics , atomic physics , geophysics , wave propagation , magnetohydrodynamics , mechanics , optics , nuclear physics , quantum mechanics , thermodynamics
Fast mode magnetosonic waves have been discovered in the distant plasma sheet boundary layers. The emissions have frequencies near the proton cyclotron frequency, are circularly or elliptically polarized in a right‐hand sense, and are propagating nearly along ( θ kB <20°). The wave compressional component can be as large as 30‐90% of the wave amplitude. The emissions are substorm related. Several possible generation mechanisms are discussed, such as resonant interactions with ∼1 ‐ 2 keV streaming protons. In the firehose instability, energization of the protons would be caused by the adiabatic compression of plasma on freshly reconnected magnetic field lines. The role that the waves may play in the heating and expansion of the plasma sheet and as a component of internal pressure which keeps open the distant tail, are both briefly discussed.