Theory of incompressible magnetohydrodynamic turbulence with scale-dependent alignment and cross-helicity

J. J. Podesta, A. Bhattacharjee

Research output: Contribution to journalArticle

43 Scopus citations

Abstract

A phenomenological anisotropic theory of MHD turbulence with nonvanishing cross-helicity is constructed based on Boldyrev's phenomenology and probabilities p and q for fluctuations δv⊥ and δb⊥ to be positively or negatively aligned. The positively aligned fluctuations occupy a fractional volume p and the negatively aligned fluctuations occupy a fractional volume q. Guided by observations suggesting that the normalized cross-helicity σc and the probabilities p and q are approximately scale invariant in the inertial range, a generalization of Boldyrev's theory is derived that depends on the three ratios w+/w-, ε+-, and p/q. It is assumed that the cascade processes for positively and negatively aligned fluctuations are both in a state of critical balance and that the eddy geometries are scale invariant. The theory reduces to Boldyrev's original theory when σc = 0, ε+ = ε-, and p = q and extends the theory of Perez and Boldyrev when σc ≠ 0. The theory is also an anisotropic generalization of the theory of Dobrowolny, Mangeney, and Veltri.

Original languageEnglish (US)
Pages (from-to)1151-1157
Number of pages7
JournalAstrophysical Journal
Volume718
Issue number2
DOIs
StatePublished - Aug 1 2010
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Keywords

  • Solar wind
  • Turbulence
  • Waves

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