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Read Full Article (file size: 380049 bytes) Cited by
GEOPHYSICAL RESEARCH LETTERS,
VOL. 31,
L21805,
doi:10.1029/2004GL021119,
2004
Discrete modes and turbulence in a wave-driven strongly magnetized plasma
Pablo Dmitruk
Bartol Research Institute, University of Delaware, Newark, Delaware, USA
William H. Matthaeus
Bartol Research Institute, University of Delaware, Newark, Delaware, USA
Louis J. Lanzerotti
Bell Labs, Lucent Technologies, Murray Hill, New Jersey, USA
Abstract
We show the coexistence of discrete modes and turbulence in numerical experiments of magnetohydrodynamics with a strong background
magnetic field. The particular system we consider is a model of an open magnetic region which we have previously used in coronal
heating studies. In the simulations shown here, Alfven waves at discrete frequencies with values corresponding to solar g-modes
and p-modes are injected at the boundary (although the question of how those modes could generate Alfven waves is not addressed).
Numerical probes are used to compute the magnetic field fluctuations at the output. The frequency spectra obtained from those
probes are broadband, but with peaks at the driving frequencies. The perpendicular (to the mean magnetic field) wavenumber
energy spectrum is of a turbulent Kolmogorov-like type, and formation of small scale structures is observed. This shows, numerically,
the possibility of persistence of discrete modes in a turbulent system.
Received 27
July
2004;
accepted 12
October
2004;
published 11
November
2004.
Index Terms: 2149 Interplanetary Physics: MHD waves and turbulence; 7863 Space Plasma Physics: Turbulence; 7509 Solar Physics, Astrophysics, and Astronomy: Corona.
Read Full Article (file size: 380049 bytes) Cited by
Citation: Dmitruk, P., W. H. Matthaeus, and L. J. Lanzerotti
(2004),
Discrete modes and turbulence in a wave-driven strongly magnetized plasma,
Geophys. Res. Lett.,
31,
L21805,
doi:10.1029/2004GL021119.
Copyright 2004 by the American Geophysical Union.
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