Thermoelectric effects in decaying homogeneous magneto-gas turbulence

Abstract

In the formulation of compressible magnetohydrodynamics (MHD) (i.e., magneto-gas dynamics), a ‘‘generalized Ohm’s law’’ is required. In particular, an electron pressure term and a ‘‘Hall effect’’ term may appear as non-negligible additions to the Ohm’s law that is conventionally used for incompressible MHD. In ‘‘high-beta’’ (i.e., relatively low magnetic energy) situations, the Hall term may be neglected (at least initially) but, as it turns out, the electron pressure term cannot be neglected. Here, three-dimensional, high-beta, homogeneous, decaying, magneto-gas turbulence is examined with regard to this additional term. Through numerical simulation, it is found that ‘‘thermoelectric effects’’ are produced that significantly alter the evolution of the magnetic field and electric current strengths.