Dynamic Alignment in Driven Magnetohydrodynamic Turbulence

Journal Article · Fri Dec 22 04:00:00 EST 2006 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.97.255002· OSTI ID:20861528

Mason, Joanne; Cattaneo, Fausto ^[1]; Boldyrev, Stanislav ^[2]

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1. Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 (United States)
2. Department of Physics, University of Wisconsin at Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)

Motivated by recent analytic predictions, we report numerical evidence showing that in driven incompressible magnetohydrodynamic turbulence the magnetic- and velocity-field fluctuations locally tend to align the directions of their polarizations. This dynamic alignment is stronger at smaller scales with the angular mismatch between the polarizations decreasing with the scale {lambda} approximately as {theta}{sub {lambda}}{proportional_to}{lambda}{sup 1/4}. This can naturally lead to a weakening of the nonlinear interactions and provide an explanation for the energy spectrum E(k){proportional_to}k{sup -3/2} that is observed in numerical experiments of strongly magnetized turbulence.

• OSTI ID: 20861528
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 25 Vol. 97; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ENERGY SPECTRA
FLUCTUATIONS
MAGNETOHYDRODYNAMICS
NONLINEAR PROBLEMS
POLARIZATION
TURBULENCE