scostep 2010 (stp12) - Leibniz-Institut für Atmosphärenphysik an der ...

STP12 Abstracts
Berlin, 12 - 16 July 2010
SCOSTEP Symposium 2010
A 3D magneto-hydrodynamic model of solar prominences
Aiouaz Tayeb, Toeroek Tibor
We aim to model a solar prominence embedded in the upper solar atmosphere taking in
account a fully 3D magnetic field, realistic thermodynamics, and energy sources, using a 3D
MHD simulation. As initial condition for the magnetic field we use the analytical model of a
bipolar active region by Titov & Demoulin (1999). This approximate force-free equilibrium
consist of an arched and twisted magnetic flux tube embedded into an ambient potential field.
This magnetic configuration contains "dips", i.e., locations where the field lines are concave
upward (U-shaped) and can carry dense plasma against gravity. The thermodynamic model
contains as initial condition a hydrostatic, pressure-balanced atmosphere that spans from the
high chromosphere through the transition region to the solar corona. The energy equation
includes radiative losses (Rosner, 1978), thermal conduction along the magnetic field
(Spitzer, 1962), electric current dissipation, and an ad-hoc heating function for the corona
(Serio et al, 1981).
Due to the spurious forces present in the magnetic field and the response of the atmosphere,
the system develops a complex dynamic behavior from the very beginning of the simulation.
The source terms of the energy equation seek to balance each other given the constraints
imposed by the magnetic field. This evolution results in evaporation of chromospheric
plasma that is expected to trigger a thermal instability and plasma condensation in the
ongoing simulation, i.e., the formation of prominence material.