HR: 15:25h
AN: SH33B-08    [Abstracts]
TI: Spectra of moderately strong anisotropic MHD turbulence in high beta plasma
AU: Kuznetsov, E
EM: kuznetso@itp.ac.ru
AF: P.N. Lebedev Physical Institute of RAS, 53 Leninsky avenue, Moscow, 119991, Russian Federation
AU: * Krasnoselskikh, V
EM: vkrasnos@cnrs-orleans.fr
AF: LPCE/CNRS-University of Orleans, 3 Avenue de la Recherche Scientifique, Orleans, 45071, France
AB: Spectra of MHD turbulence are studied at a moderate level of beta. For small amplitude waves the interactions can be neglected. The increase of wave amplitudes results in the regime of weak turbulence. For larger amplitudes the nonlinear effects become comparable or larger than the wave dispersion, the weak turbulence approach is not applicable anymore. In this case the main nonlinear effect for acoustic waves is the wave breaking that results in the formation of shocks. This process is purely coherent and the expanding caustics should be treated as coherent elementary entities of wave turbulence. The jumps of density as well as the density singularities are known to result in a power-law tails in the short-wavelength turbulence spectrum. Kadomtsev and Petviashvili suggested that the ion acoustic turbulence in a plasma can be considered as a randomly distributed set of shocks and found the spectrum of the isotropic energy distribution E(k)~k^-2. Our goal is to determine how the KP spectrum is modified in the presence of the strong enough anisotropy in a plasma.
DE: 2109 Discontinuities (7811)
DE: 7827 Kinetic and MHD theory
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting