Misc,
2D MHD and 1D HD models of a solar flare &\#45;&\#45; a comprehensive comparison of the results
(Oct 1, 2015)
Abstract
Without any doubt solar flaring loops possess a multi-thread internal
structure that is poorly resolved and there are no means to observe heating
episodes and thermodynamic evolution of the individual threads. These
limitations cause fundamental problems in numerical modelling of flaring loops,
such as selection of a structure and a number of threads, and an implementation
of a proper model of the energy deposition process. A set of 1D hydrodynamic
and 2D magnetohydrodynamic models of a flaring loop are developed to compare
energy redistribution and plasma dynamics in the course of a prototypical solar
flare. Basic parameters of the modeled loop are set according to the progenitor
M1.8 flare recorded in the AR10126 on September 20, 2002 between 09:21 UT and
09:50 UT. The non-ideal 1D models include thermal conduction and radiative
losses of the optically thin plasma as energy loss mechanisms, while the
non-ideal 2D models take into account viscosity and thermal conduction as
energy loss mechanisms only. The 2D models have a continuous distribution of
the parameters of the plasma across the loop, and are powered by varying in
time and space along and across the loop heating flux. We show that such 2D
models are a borderline case of a multi-thread internal structure of the
flaring loop, with a filling factor equal to one. Despite the assumptions used
in applied 2D models, their overall success in replicating the observations
suggests that they can be adopted as a correct approximation of the observed
flaring structures.
