Turbulent Density Spectrum in Solar Wind Plasma

Dastgeer Shaikh; G. P. Zank

doi:10.1111/j.1365-2966.2009.15881.x

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arXiv · 0910.2904

Turbulent Density Spectrum in Solar Wind Plasma

Dastgeer Shaikh·G. P. Zank

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Abstract

The density fluctuation spectrum in the solar wind reveals a Kolmogorov-like scaling with a spectral slope of -5/3 in wavenumber space. The energy transfer process in the magnetized solar wind, characterized typically by MHD turbulence, over extended length-scales remains an unresolved paradox of modern turbulence theories, raising the question of how a compressible magnetofluid exhibits a turbulent spectrum that is 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 fluid. It is shown that a Kolmogorov-like density spectrum can develop by plasma motions that are dominated by Alfvénic cascades whereas compressive modes are dissipated.

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Dastgeer Shaikh, G. P. Zank. 2009-10-15. Turbulent Density Spectrum in Solar Wind Plasma. https://doi.org/10.1111/j.1365-2966.2009.15881.x

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