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arXiv · 0907.0999

Turbulent Spectra in the Solar Wind Plasma

Dastgeer Shaikh·G. P. Zank
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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.

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Dastgeer Shaikh, G. P. Zank. 2009-07-06. Turbulent Spectra in the Solar Wind Plasma. https://doi.org/10.1017/s0022377809990237

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