Rocket studies of plasma turbulence in the equatorial and auroral electrojets
Rocket observations of plasma turbulence in the equatorial and auroral electrojets have been studied in detail. Intense electric field and plasma density fluctuations characterize the collisional two-stream and gradient drift instabilities, showing a marked spectral differentiation with respect to height consistent with changes in the local sources of free energy. The interpretation of the frequencies and amplitudes of irregularities detected by in-situ probes travelling at comparable speeds to the waves is discussed in detail. Observations from three rockets in the daytime equatorial electrojet during strong, mild, and weak currents show that the linear theory accounts for the general height and wavelength domains of the irregularities. In the strong case, laminar two-stream waves were observed where the current was strongest and the density gradient was stable. The data suggest phase velocities that were comparable to the electron drift velocity (approx.500 m/s) and peak wavelengths (2-3 m) that agree with kinetic theory. Vertically propagating waves observed here may have been generated by mode coupling. Where the gradient was unstable, large amplitude, kilometer scale waves dominated, although the linear gradient drift growth rate peaks at a few hundred meters. The amplitudes (10-15 mV/m) of these horizontal waves were strong enough to drive vertical two-stream waves.
- Research Organization:
- Cornell Univ., Ithaca, NY (USA)
- OSTI ID:
- 6931479
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
ELECTROJETS
PLASMA MICROINSTABILITIES
PLASMA WAVES
AMPLITUDES
ELECTRIC FIELDS
FLUCTUATIONS
PHASE VELOCITY
PLASMA DENSITY
TURBULENCE
CURRENTS
ELECTRIC CURRENTS
INSTABILITY
PLASMA INSTABILITY
VARIATIONS
VELOCITY
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena