Abstract
A four-field system of equations has been recently derived from the compressible magnetohydrodynamic (MHD) equations to describe turbulence in the solar wind. These equations apply to a plasma permeated by a spatially varying mean magnetic field when the plasma beta is of the order unity or less. In the presence of spatial inhomogeneities, the four-field equations predict pressure fluctuations of the order of the Mach number of the turbulence, as observed by Helios 1 and 2. It is shown that inhomogeneities that occur only in the form of pressure-balanced structures cannot account for density fluctuations as large as the Mach number of the turbulence. Numerical predictions from the four-field and compressible MHD equations are compared using the same initial condition. The comparison shows that the predictions of the four-field model are qualitatively consistent with the predictions of the compressible MHD model and suggests that the four-field model is a viable model of compressible turbulence in the solar wind.
Original language | English (US) |
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Article number | 1999JA900327 |
Pages (from-to) | 24835-24843 |
Number of pages | 9 |
Journal | Journal of Geophysical Research: Space Physics |
Volume | 104 |
Issue number | A11 |
DOIs | |
State | Published - Nov 1 1999 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Geochemistry and Petrology
- Geophysics
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science
- Atmospheric Science
- Astronomy and Astrophysics
- Oceanography