The role of MHD turbulence on coronal heating and in the solar wind

GOMEZ, DANIEL; ANDRÉS, NAHUEL; MARTIN, LUIS; DMITRUK, PABLO

San Francisco

Conferencia; Fall meeting of the American Geophysical Union; 2013

American Geophysical Union

Even though one-fluid magnetohydrodynamics (MHD) is a reasonable theoretical framework to describe the large scale dynamics of fully ionized plasmas, several phenomena observed in the solar wind require at least a two-fluid MHD description. As a first approximation, the role of mass-less electrons translate into the so-called Hall effect, which becomes non-negligible at spatial scales as small as the ion skin depth (i.e. c/w_pi). At even smaller scales, comparable to the electron skin depth (i.e. c/w_pe), the effect of finite electron mass needs to be considered. We show how these kinetic effects can be properly included in a fluidistic description of fully ionized plasmas. Moreover, we show the results of numerical simulations corresponding to different applications. For example, MHD simulations of coronal loops driven at their footpoints to show the development of a turbulent regime and the heating of the plasma as a result of the ensuing energy cascade. We also present 2.5D Hall-MHD simulations to show the role of the Hall and electron-inertia effects in the dissipative structures being formed in low-density plasmas such as the one of the solar wind at 1 AU and beyond.