Investigating chromospheric evaporation using multidimensional flare simulations.

A solar flare is a very explosive phenomenon in the solar atmosphere that has great impact for space weather. In a flare event, up to 10^32 ergs of magnetic energy can be released within minutes. A large portion of the energy is transported down to the solar chromosphere by non-thermal electrons and thermal conduction, producing evaporation flows of several hundreds of km/s. The evaporation flows fill the flare loops with hot and dense plasma, leading to highly enhanced emissions of flare loops in soft X-ray and high temperature extreme ultraviolet spectral lines. Numerical simulations have been widely applied to investigate the evaporations, however, mainly using one dimensional models. In those 1D simulations, both the reconnection process which acts as energy source of non-thermal electrons and heat flux, and the impact of the changing simulated flux tubes, have not been considered. Here in this proposal we aim to solve these problems by extending the numerical studies to multi-dimensional settings, including the reconnection process, making the simulations much more self-consistent. We plan to evaluate and compare the contributions of non-thermal electron deposition and thermal conduction in the evaporations. Our study will help us understand the energy closure problem in solar flares much better.

Keywords:Magnetohydrodynamic (MHD), Solar flares, Solar chromosphere

Disciplines:Space plasma physics and solar physics