Nonlinear decay of magnetic helicity in magnetohydrodynamic turbulence with a mean magnetic field

Details Nonlinear decay of magnetic helicity in magnetohydrodynamic turbulence with a mean magnetic field Nonlinear decay of magnetic helicity in magnetohydrodynamic turbulence with a mean magnetic field

Feb 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994jgr....99.2567s&link_type=abstract

Journal of Geophysical Research (ISSN 0148-0227), vol. 99, no. A2, p. 2567-2576

Mathematics

Logic

30

Electric Fields, Field Aligned Currents, Helical Flow, Magnetic Fields, Magnetohydrodynamic Turbulence, Computerized Simulation, Decay Rates, Energy Spectra, Incompressible Flow, Wavelengths

Scientific paper

We show that the magnetic helicity associated with fluctuations in homogeneous incompressible magnetohydrodynamic (MHD) turbulence with a mean magnetic field decays in time because of nonlinear processes. Evidence is obtained numerically, by use of both dissipative and nondissipative spectral method simulations. The described effect stands in contrast to expectations based on studies of MHD turbulence without an applied mean field, in which magnetic helicity is transferred nonlinearly to long wavelengths and is preserved in time because of selective decay when dissipation is present. The process of nonlinear decay is described in terms of a generalized ideal helicity invariant and is characterized by the transient production of a mean induced electric field aligned with the applied magnetic field, an effect reminiscent of the alpha effect in dynamo theory. A simple phenomenological model for the decay process is proposed.

Affiliated with

Also associated with

No associations

Rating

Nonlinear decay of magnetic helicity in magnetohydrodynamic turbulence with a mean magnetic field does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Nonlinear decay of magnetic helicity in magnetohydrodynamic turbulence with a mean magnetic field, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonlinear decay of magnetic helicity in magnetohydrodynamic turbulence with a mean magnetic field will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1017347