Ion anisotropy driven waves in the earth's magnetosheath and plasma depletion layer

Conference · Fri Jan 01 04:00:00 EST 1993

DOI:https://doi.org/10.1029/GM084p0111· OSTI ID:6383367

Denton, R E; Hudson, M K ^[1]; Anderson, B J ^[2]; Fuselier, S A ^[3]; Gary, S P ^[4]

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1. Dartmouth Coll., Hanover, NH (United States). Dept. of Physics and Astronomy
2. Johns Hopkins Univ., Laurel, MD (United States). Applied Physics Lab.
3. Lockheed Palo Alto Research Labs., CA (United States)
4. Los Alamos National Lab., NM (United States)

Recent studies of low frequency waves ([omega][sub r] [le] [Omega][sub p], where [Omega][sub p] is the proton gyrofrequency) observed by AMPTE/CCE in the plasma depletion layer and magnetosheath proper arereviewed. These waves are shown to be well identified with ion cyclotron and mirror mode waves. By statistically analyzing the transitions between the magnetopause and time intervals with ion cyclotron and mirror mode waves, it is established that the regions in which ion cyclotron waves occur are between the magnetopause and the regions where the mirror mode is observed. This result is shown to follow from the fact that the wave spectral properties are ordered with respect to the proton parallel beta, [beta][sub [parallel]p]. The later result is predicted by linear Vlasov theory using a simple model for the magnetosheath and plasma depletion layer. Thus, the observed spectral type can be associated with relative distance from the magnetopause. The anisotropy-beta relation, A[sub p] [triple bond] (T[perpendicular]/T[sub [parallel]])[sub p] [minus] 1 = 0.50[beta][sub [parallel]p][sup [minus]0.48] results from the fact that the waves pitch angle scatter the particles so that the plasma is near marginal stability, and is a fundamental constraint on the plasma.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6383367
• Report Number(s): LA-UR-93-1470; CONF-9302115--3; ON: DE93012751
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
BOLTZMANN-VLASOV EQUATION
CYCLOTRON RESONANCE
DIFFERENTIAL EQUATIONS
EQUATIONS
INSTABILITY
INTERPLANETARY MAGNETIC FIELDS
ION CYCLOTRON-RESONANCE
ION PLASMA WAVES
ION WAVES
MAGNETIC FIELDS
MAGNETOPAUSE
MAGNETOSHEATH
PARTIAL DIFFERENTIAL EQUATIONS
PLASMA INSTABILITY
PLASMA WAVES
RESONANCE
SPACE VEHICLES
VEHICLES
WAVE PROPAGATION