Electron inertial effects in highly rolledup MHDscale KelvinHelmholtz vortices
Abstract
In order to understand the universality of substantial nonMHD effects within MHDscale (large scale) KelvinHelmholtz (KH) vortices, we have performed twodimensional simulations by a twofluid system including finite electron inertial effects. An MHDscale velocity shear with density gradient between the two regions is set up and evolution of MHDscale KH mode is followed. Here we concentrate on the cases with intheplane magnetic field component. We particularly focus on the case where magnetic field lines on both sides of the shear layer are parallel to each other. In this case, magnetic reconnection within the MHDscale vortex occurs by the electron inertial effects when the vortex highly rollsup. In the highly rolledup vortex, the field lines are stretched into an antiparallel geometry overcoming the tension of intheplane magnetic field. The number of the magnetic islands formed by reconnection and the degree of the electron acceleration in the islands depend on the size of the vortex measured by the ion inertial length and the electron inertial length, respectively. On the basis of these results, we advocate the general importance of the electron effects in an MHDscale KH vortex and discuss its relevance to dynamics of the LLBL. The electron inertia effectively affects the structures of highly rolledup MHDscale vortices over a wide parameter range including the representative LLBL parameter, by which fascinating effects that are not expected in pureMHD are likely to be produced.
 Publication:

35th COSPAR Scientific Assembly
 Pub Date:
 2004
 Bibcode:
 2004cosp...35.1340N