### 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 σ_{c} 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^{+}/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 σ_{c} = 0, ε^{+} = ε^{-}, and p = q and extends the theory of Perez and Boldyrev when σ_{c} ≠ 0. The theory is also an anisotropic generalization of the theory of Dobrowolny, Mangeney, and Veltri.

Original language | English (US) |
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Pages (from-to) | 1151-1157 |

Number of pages | 7 |

Journal | Astrophysical Journal |

Volume | 718 |

Issue number | 2 |

DOIs | |

State | Published - Aug 1 2010 |

Externally published | Yes |

### All Science Journal Classification (ASJC) codes

- Astronomy and Astrophysics
- Space and Planetary Science

### Keywords

- Solar wind
- Turbulence
- Waves