Plasma collective modes driven by velocity gradients

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA095iA12p21213· OSTI ID:5376783

Basu, B ^[1]; Coppi, B ^[2]

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1. Air Force Geophysics Lab., Bedford, MA (USA)
2. Massachusetts Inst. of Tech., Cambridge (USA)

Collisional modes driven by shear in the plasma flow velocity V{sub {parallel}}, parallel to the magnetic field, are shown to exist over significant scale distances while subject to the constraints imposed by gradients in the transverse velocity V{sub E} {proportional to} E {times} B. These constraints make the modes localized over finite distances around the surfaces where V{sub E} reaches a maximum or a minimum. Composite modes that can be constructed as a sequence or a superposition of these elementary normal modes can be excited in regions where the transverse velocity acquires a plateau type of profile that is assumed to be formed after macroscopic Kelvin-Helmholtz modes associated with the shear of V{sub E} have reached their saturation stage. Thus a significant rate of longitudinal plasma momentum transport in the transverse direction to the magnetic field can be produced. The relevance of this analysis to the fluctuations observed in the auroral F region is discussed.

• OSTI ID: 5376783
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:A12; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAL ZONES
PLASMA WAVES
F REGION
HELMHOLTZ INSTABILITY
MAGNETIC FIELDS
PLASMA DRIFT
QUASILINEAR PROBLEMS
SHEAR
VELOCITY
EARTH ATMOSPHERE
INSTABILITY
IONOSPHERE
PLANETARY IONOSPHERES
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena