HR: 0800h
AN: SH41A-1119    [Abstracts]
TI: A ``Wave Plus Turbulence'' Phenomenology for MHD With a Mean Magnetic Field
AU: * Oughton, S
EM: seano@waikato.ac.nz
AF: University of Waikato, Department of Mathematics Private Bag 3105, Hamilton, 2001 New Zealand
AU: Matthaeus, W H
EM: yswhm@bartol.udel.edu
AF: Bartol Research Institute, Sharp Laboratory University of Delaware, Newark, DE 19716 United States
AU: Dmitruk, P
EM: pablo@bartol.udel.edu
AF: Bartol Research Institute, Sharp Laboratory University of Delaware, Newark, DE 19716 United States
AB: The dynamics of MHD systems often involve an intricate interaction between (Alfvén) waves and nonlinear fluctuations (or, turbulence). Here we discuss a two-component phenomenology for MHD, wherein the fluctuations are treated as being of either a ``wave-like'' type or a turbulence type. The distinction between the types is made in Fourier space, on the basis of which of the wave and nonlinear timescales is the shorter. The phenomenology is a one-point closure and models the evolution of the energy in each component and the associated lengthscales. It is valid for arbitrary mean magnetic field strengths (B_0), and reproduces well-known results in appropriate limiting cases such as either very weak or very strong B_0. The development of the model will be outlined and solutions for a range of initial conditions and forcing types will be presented.
DE: 7827 Kinetic and MHD theory
DE: 7863 Turbulence (4490)
DE: 7868 Wave/wave interactions
DE: 9800 GENERAL OR MISCELLANEOUS
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005