Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-05T21:42:42.178Z Has data issue: false hasContentIssue false
  • English
  • Français

Turbulent spectra in the solar wind plasma

Published online by Cambridge University Press:  29 July 2009

DASTGEER SHAIKH  and
G. P. ZANK
DASTGEER SHAIKH
Affiliation:
Department of Physics and Center for Space Physics and Aeronomic Research (CSPAR), University of Alabama at Huntsville, Huntsville, AL 35805, USA ([email protected])
G. P. ZANK
Affiliation:
Department of Physics and Center for Space Physics and Aeronomic Research (CSPAR), University of Alabama at Huntsville, Huntsville, AL 35805, USA ([email protected])
Get access Rights & Permissions [Opens in a new window]

Abstract

Observations of interstellar scintillations at radio wavelengths reveal a Kolmogorov-like scaling of the electron density spectrum with a spectral slope of −5/3 over six decades in wavenumber space. A similar turbulent density spectrum in the solar wind plasma has been reported. The energy transfer process in the magnetized solar wind plasma over such extended length scales remains an unresolved paradox of modern turbulence theories, raising the especially intriguing question of how a compressible magnetized solar wind exhibits a turbulent spectrum that is a characteristic of an incompressible hydrodynamic fluid. To address these questions, we have undertaken three-dimensional time-dependent numerical simulations of a compressible magnetohydrodynamic fluid describing super-Alfvénic, supersonic and strongly magnetized plasma. It is shown that the observed Kolmogorov-like (−5/3) spectrum can develop in the solar wind plasma by supersonic plasma motions that dissipate into highly subsonic motion that passively convect density fluctuations.

Type
Papers
Information
Journal of Plasma Physics , Volume 76 , Issue 2 , April 2010 , pp. 183 - 191
Copyright
Copyright © Cambridge University Press 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Armstrong, J. W., Cordes, J. M. and Rickett, B. J. 1981 Density power spectrum in the local interstellar medium. Nature 291, 561–564.CrossRefGoogle Scholar
Armstrong, J. W., Rickett, B. J. and Spangler, S. 1995 Electron density power spectrum in the local interstellar medium. Astorphys. J. 443, 209–221.CrossRefGoogle Scholar
Bellamy, B. R., Cairns, I. H. and Smith, C. W. 2005 Voyager spectra of density turbulence from 1 AU to the outer heliosphere. J. Geophys. Res. 110, A10104. DOI:10.1029/2004JA010952.Google Scholar
Bhattacharjee, A., Ng, C. S. and Spangler, S. R. 1998 Weakly compressible magnetohydrodynamic turbulence in the solar wind and the interstellar medium. Astrophys. J. 494, 409.CrossRefGoogle Scholar
Bruno, R. and Carbone, V. 2005 The solar wind as a Turbulence Laboratory. Living Rev. Solar Phys. 2, 4.CrossRefGoogle Scholar
Cho and Lazarian 2003 MNRAS 345, 325.CrossRefGoogle Scholar
Goldstein, M. L., Roberts, D. A. and Matthaeus, W. H. 1995 Ann. Rev. Astron. Astrophys. 33, 283–325.Google Scholar
Iroshnikov, P. S. 1963 Turbulence of a conducting fluid in a strong magnetic field. Astron. Zh. 40, 742.Google Scholar
Kissmann, R., Kleimann, J., Fichtner, H. and Grauer, R. 2008 Local turbulence simulations for the multiphase ISM. MNRAS 391, 1577.CrossRefGoogle Scholar
Kolmogorov, A. N. 1941 On degeneration of isotropic turbulence in an incompressible viscous liquid. Dokl. Akad. Nauk SSSR 31, 538–541.Google Scholar
Kraichnan, R. H. 1965 Inertial range spectrum in hydromagnetic turbulence. Phys. Fluids 8, 1385–1387.CrossRefGoogle Scholar
Leamon, R., Smith, C. W., Ness, N. F. and Matthaeus, W. H. 1998 Observational constraints on the dynamics of the interplanetary magnetic field dissipation range. J. Geophys. Res. 103 (A3), 4775–4787.CrossRefGoogle Scholar
Matthaeus, W. H. and Brown, M. 1988 Nearly incompressible magnetohydrodynamics at low Mach number. Phys. Fluids 31, 3634–3644.CrossRefGoogle Scholar
Marsch, E. and Tu, C.-Y. 1990 On the radial evolution of MHD turbulence in the inner heliosphere. J. Geophys. Res. 95, 8211–8229.CrossRefGoogle Scholar
Marsch, E. and Tu, C.-Y. 1990 Spectral and spatial evolution of compressible turbulence in the inner SW. J. Geophys. Res. 95, 11,945–11,956.CrossRefGoogle Scholar
Matthaeus, W. H., Klein, L. W., Ghosh, S. and Brown, M. R. 1991 Nearly incompressible magnetohydrodynamics, pseudosound, and solar wind fluctuations. J. Geophys. Res. 96, 5421–5435.Google Scholar
McComb, W. D. 1990 The Physics of Fluid Turbulence. Claredon: Oxford University Press.CrossRefGoogle Scholar
Montgomery, D. C., Brown, M. R. and Matthaeus, W. H. 1987 Density fluctuation spectra in magnetohydrodynamic turbulence. J. Geophys. Res. 92, 282–284.CrossRefGoogle Scholar
Ng, C. S., Bhattacharjee, A., Germaschewiski, K. and Galtier, S. 2003, Anisotropic fluid turbulence in the interstellar medium and SW. Phys. Plasmas 10, 1954.CrossRefGoogle Scholar
Shaikh, D. and Zank, G. P. 2006 The Astrophysical Journal 640, L195–L198.Google Scholar
Shaikh, D. and Zank, G. P. 2007 Turbulence and Nonlinear Processes in Astrophysical Plasmas: Sixth Annual International Astrophysics Conference. AIP Conf. Proc. 932, 111.CrossRefGoogle Scholar
Shaikh, D. and Zank, G. P. 2007 Astrophys. J. 656, L17–L20.Google Scholar
Tu, C.-Y., Marsch, E. and Rosenbauer, H., 1991 Temperature fluctuation spectra in the inner solar wind. Ann. Geophys. 9, 748–753.Google Scholar
Zank, G. P. and Matthaeus, W. H. 1993 Nearly incompressible fluids. II: Magnetohydrodynamics, turbulence, and waves. Phys. Fluids A5, 257–273.CrossRefGoogle Scholar
Zank, G. P. and Matthaeus, W. H. 1990 Nearly incompressible hydrodynamics and heat conduction. Phys. Rev. Lett. 64, 1243–1246.CrossRefGoogle ScholarPubMed
Zank, G. P. and Matthaeus, W. H. 1991 The equations of nearly incompressible fluids. I: Hydrodynamics, turbulence, and waves. Phys. Fluids A 3, 69–82.CrossRefGoogle Scholar