Bremen 2000 – wissenschaftliches Programm
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EP: Extraterrestrische Physik
EP 15: Poster Extraterrestrische Physik
EP 15.4: Poster
Mittwoch, 22. März 2000, 16:00–16:45, Foyer
Temperature-anisotropy driven turbulence in space plasma — •C.-V. Meister1, B.P. Besser2, M.I. Pudovkin3, and N.S. Dziourkevitch1 — 1Astrophysical Inst. Potsdam — 2Inst. for Space Res. Graz — 3St. Petersburg Univ.
The calculation of collision frequencies and relaxation times of temperature-anisotropy driven turbulence is very important for the interpretation of recent satellite data obtained for the solar (CORONAS, SOHO) and earth magnetosheath (AMPTE, ISEE) plasmas. Thus here the dispersion of proton-temperature anisotropy driven ion-cyclotron and mirror waves in space plasma is studied. In comparison with the works of Gary, Fuselier and Anderson within linear plasma theory (J. Geophys. Res. 97, 8519-8529, 1992; 98, 1481-1488, 1993), analytical expressions are found for several limiting conditions. There comparing with earlier works of Hasegawa (Revs. Geophys. Space Phys. 9, 703-772, 1971), finite values of the parallel component of the temperature are taken into account. Then, using the simple expressions for the wave dispersion, the energy spectrum of the waves as function of the wave number and the propagation angle is found basing on the expression for space-time spectral functions of the energy of electromagnetic waves usually considered within Klimontovich theory of turbulence. First estimates are given for the effective wave-particle collision frequencies of the turbulent plasmas of the earth’s magnetosheath and the solar atmosphere.