Accession Number : ADA185471

Title :   Nature and the Nonlinear Evolution of Electrostatic Waves Associated with the AMPTE (Active Magnetosphere Particle Tracer Explorers) Solar Wind Releases.

Descriptive Note : Progress rept.,

Corporate Author : IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s) : Omidi, N ; Akimoto, K ; Gurnett, D A ; Anderson, R R

PDF Url : ADA185471

Report Date : Jul 1987

Pagination or Media Count : 54

Abstract : The nonlinear evolution of the electrostatic waves observed during the AMPTE (Active Magnetosphere Particle Tracer Explorers) solar wind releases is investigated. Previous linear studies indicate two distinct sets of instabilities may be responsible for the generation. One set consists of ion-acoustic type instabilities which are insensitive to the presence of a background magnetic field, while the other group corresponds to the modified two stream instabilities and requires the solar wind flow to be across the ambient magnetic field. To establish which set of instabilities are more viable a detailed linear Vlasov theory has been conducted by numerically solving the full electromagnetic dispersion relation. In addition both the plasma wave as well as the magnetic field measurements by the IRM (Ion Release Module) spacecraft were used to correlate the frequency and the power of the observed waves with the magnitude and the direction of the solar wind magnetic field. The results of these analyses indicate that the ion-acoustic type instabilities have growth rates that are an order of magnitude or more larger than those of the modified two stream instabilities. The results show that both the solar wind protons and the released ions may be heated and accelerated in the directions oblique to the solar wind flow velocity.

Descriptors :   *SOLAR WIND, BACKGROUND, DISPERSION RELATIONS, ELECTROMAGNETISM, ELECTROSTATICS, EVOLUTION(GENERAL), GROWTH(GENERAL), IONS, MAGNETIC FIELDS, MEASUREMENT, MODULAR CONSTRUCTION, NONLINEAR SYSTEMS, PLASMA WAVES, PROTONS, RATES, RELEASE, SPACECRAFT, WAVES, WIND VELOCITY, DIRECTIONAL, TRACER STUDIES, LITHIUM, BARIUM, MOMENTUM TRANSFER, ION ION INTERACTIONS

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE