Local relaxation and scale-dependent alignment in compressible, magnetized turbulence

Abstract

Driven net- and no-net-flux MHD turbulence simulations up to $10,368^3$ reveal sign-mixed velocity--magnetic, velocity--vorticity, and magnetic--current aligned patches below the energy equipartition scale. The first two angles scale as ${\lambda }^{1/8}$ and ${\lambda }^{1/16}$, while the third angle varies weakly with scale. We develop and test a constant-flux transport model for departures from relaxed states, which predicts both exponents. These findings affect eddy anisotropy, reconnection-mediated turbulence onset, large-scale dynamos, and the nature of magnetized turbulence.

arXiv comment6 pages including acknowledgments, 3 main figures; 14 pages total, including Supplemental Material with 2 figures. Accepted in PRL