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Title: Nonlinear wave interactions in shallow water magnetohydrodynamics of astrophysical plasma

Abstract

The rotating magnetohydrodynamic flows of a thin layer of astrophysical and space plasmas with a free surface in a vertical external magnetic field are considered in the shallow water approximation. The presence of a vertical external magnetic field changes significantly the dynamics of wave processes in an astrophysical plasma, in contrast to a neutral fluid and a plasma layer in an external toroidal magnetic field. There are three-wave nonlinear interactions in the case under consideration. Using the asymptotic method of multiscale expansions, we have derived nonlinear equations for the interaction of wave packets: three magneto- Poincare waves, three magnetostrophic waves, two magneto-Poincare and one magnetostrophic waves, and two magnetostrophic and one magneto-Poincare waves. The existence of decay instabilities and parametric amplification is predicted. We show that a magneto-Poincare wave decays into two magneto-Poincare waves, a magnetostrophic wave decays into two magnetostrophic waves, a magneto-Poincare wave decays into one magneto-Poincare and one magnetostrophic waves, and a magnetostrophic wave decays into one magnetostrophic and one magneto-Poincare waves. There are the following parametric amplification mechanisms: the parametric amplification of magneto-Poincare waves, the parametric amplification of magnetostrophic waves, the amplification of a magneto-Poincare wave in the field of a magnetostrophic wave, and the amplificationmore » of a magnetostrophic wave in the field of a magneto-Poincare wave. The instability growth rates and parametric amplification factors have been found for the corresponding processes.« less

Authors:
;  [1]
  1. Russian Academy of Sciences, Space Research Institute (Russian Federation)
Publication Date:
OSTI Identifier:
22617281
Resource Type:
Journal Article
Journal Name:
Journal of Experimental and Theoretical Physics
Additional Journal Information:
Journal Volume: 122; Journal Issue: 5; Other Information: Copyright (c) 2016 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1063-7761
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMPLIFICATION; APPROXIMATIONS; ASTROPHYSICS; ASYMPTOTIC SOLUTIONS; DECAY; DECAY INSTABILITY; EQUATIONS; EXPANSION; FLUIDS; INSTABILITY GROWTH RATES; INTERACTIONS; LAYERS; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; NONLINEAR PROBLEMS; PLASMA; SPACE; SURFACES; THIN FILMS; WAVE PACKETS

Citation Formats

Klimachkov, D. A., E-mail: klimachkovdmitry@gmail.com, and Petrosyan, A. S., E-mail: apetrosy@iki.rssi.ru. Nonlinear wave interactions in shallow water magnetohydrodynamics of astrophysical plasma. United States: N. p., 2016. Web. doi:10.1134/S1063776116040178.
Klimachkov, D. A., E-mail: klimachkovdmitry@gmail.com, & Petrosyan, A. S., E-mail: apetrosy@iki.rssi.ru. Nonlinear wave interactions in shallow water magnetohydrodynamics of astrophysical plasma. United States. https://doi.org/10.1134/S1063776116040178
Klimachkov, D. A., E-mail: klimachkovdmitry@gmail.com, and Petrosyan, A. S., E-mail: apetrosy@iki.rssi.ru. 2016. "Nonlinear wave interactions in shallow water magnetohydrodynamics of astrophysical plasma". United States. https://doi.org/10.1134/S1063776116040178.
@article{osti_22617281,
title = {Nonlinear wave interactions in shallow water magnetohydrodynamics of astrophysical plasma},
author = {Klimachkov, D. A., E-mail: klimachkovdmitry@gmail.com and Petrosyan, A. S., E-mail: apetrosy@iki.rssi.ru},
abstractNote = {The rotating magnetohydrodynamic flows of a thin layer of astrophysical and space plasmas with a free surface in a vertical external magnetic field are considered in the shallow water approximation. The presence of a vertical external magnetic field changes significantly the dynamics of wave processes in an astrophysical plasma, in contrast to a neutral fluid and a plasma layer in an external toroidal magnetic field. There are three-wave nonlinear interactions in the case under consideration. Using the asymptotic method of multiscale expansions, we have derived nonlinear equations for the interaction of wave packets: three magneto- Poincare waves, three magnetostrophic waves, two magneto-Poincare and one magnetostrophic waves, and two magnetostrophic and one magneto-Poincare waves. The existence of decay instabilities and parametric amplification is predicted. We show that a magneto-Poincare wave decays into two magneto-Poincare waves, a magnetostrophic wave decays into two magnetostrophic waves, a magneto-Poincare wave decays into one magneto-Poincare and one magnetostrophic waves, and a magnetostrophic wave decays into one magnetostrophic and one magneto-Poincare waves. There are the following parametric amplification mechanisms: the parametric amplification of magneto-Poincare waves, the parametric amplification of magnetostrophic waves, the amplification of a magneto-Poincare wave in the field of a magnetostrophic wave, and the amplification of a magnetostrophic wave in the field of a magneto-Poincare wave. The instability growth rates and parametric amplification factors have been found for the corresponding processes.},
doi = {10.1134/S1063776116040178},
url = {https://www.osti.gov/biblio/22617281}, journal = {Journal of Experimental and Theoretical Physics},
issn = {1063-7761},
number = 5,
volume = 122,
place = {United States},
year = {Sun May 15 00:00:00 EDT 2016},
month = {Sun May 15 00:00:00 EDT 2016}
}