Strong anisotropic MHD turbulence with cross helicity
This paper proposes a new phenomenology for strong incompressible MHD turbulence with nonzero cross helicity. This phenomenology is then developed into a quantitative Fokker-Planck model that describes the time evolution of the anisotropic power spectra of the fluctuations propagating parallel and antiparallel to the background magnetic field B-0. It is found that in steady state the power spectra of the magnetic field and total energy are steeper than k(perpendicular to)(-5/3) and become increasingly steep as C/epsilon increases, where C = integral d(3)x v . B is the cross helicity, epsilon is the fluctuation energy, and k(perpendicular to) is the wavevector component perpendicular to B-0. Increasing C with fixed epsilon increases the time required for energy to cascade to smaller scales, reduces the cascade power, and increases the anisotropy of the small-scale fluctuations. The implications of these results for the solar wind and solar corona are discussed in some detail.
UNIV CHICAGO PRESS
Digital Object Identifier (DOI)
Chandran, Benjamin D.G., "Strong anisotropic MHD turbulence with cross helicity" (2008). Astrophysical Journal. 10.
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