Alfven waves in the auroral ionosphere: A numerical model compared with measurements

Journal Article · Wed Jan 01 04:00:00 EST 1992 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JA02300· OSTI ID:5557552

Knudsen, D J; Kelley, M C ^[1]; Vickrey, J F ^[2]

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1. Cornell Univ., Ithaca, NY (United States)
2. SRI International, Menlo Park, CA (United States)

The authors solve a linear numerical model of Alfven waves reflecting from the high-latitude ionosphere, both to better understanding the role of the ionosphere in the magnetosphere/ionosphere coupling process and to compare model results with in situ measurements. They use the model to compute the frequency-dependent amplitude and phase relations between the meridional electric and the zonal magnetic fields due to Alfven waves. These relations are compared with measurements taken by an auroral sounding rocket flow in the morningside oval and by the HILAT satellite traversing the oval at local noon. The sounding rocket's trajectory was mostly parallel to the auroral oval, and is measured enhanced fluctuating field energy in regions of electron precipitation. The rocket-measured phase data are in excellent agreement with the Alfven wave model, and the relation between the modeled and the measured by HILAT are related by the height-integrated Pedersen conductivity {Sigma}{sub p}, indicating that the measured field fluctuations were due mainly to structured field-aligned current systems. A reason for the relative lack of Alfven wave energy in the HILAT measurements could be the fact that the satellite traveled mostly perpendicular to the oval and therefore quickly traversed narrow regions of electron precipitation and associated wave activity.

• OSTI ID: 5557552
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 97:A1; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALFVEN WAVES
AURORAE
AURORAL OVAL
AURORAL ZONES
CHARGED-PARTICLE PRECIPITATION
COMPARATIVE EVALUATIONS
CURRENTS
EARTH ATMOSPHERE
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRIC FIELDS
ELECTRICAL PROPERTIES
ELECTRON PRECIPITATION
EVALUATION
FREQUENCY DEPENDENCE
HYDROMAGNETIC WAVES
IONOSPHERE
MATHEMATICAL MODELS
PHYSICAL PROPERTIES
PLANETARY IONOSPHERES
REFLECTION
STANDING WAVES