Abstract Details


Name: Jordi De Jonghe
Affiliation: Centre for mathematical Plasma Astrophysics, KU Leuven, Belgium
Conference ID: TVS202510180
Title: Thermal instability in the stratified solar atmosphere, coronal loops and current sheets
Authors and Co-Authors: Rony Keppens, Adrian Kelly, Samrat Sen
Abstract Type: Invited by SOC
Abstract: Though the extremely high temperature of the solar corona is one of the biggest outstanding questions in solar physics, the corona is also host to a variety of structures and phenomena orders of magnitude cooler, like prominences and coronal rain. The driving mechanism behind the cooling of coronal plasma is a thermal runaway effect, in which a decrease in temperature due to radiative cooling necessitates an increase in plasma density, which causes even stronger radiative cooling. This catastrophic cooling is commonly known as thermal instability. In the magnetohydrodynamic plasma description this thermal instability depends predominantly on three effects: radiative cooling, background heating, and thermal conduction. With a linear stability analysis, either analytically or numerically with the Legolas code, it can be shown that these thermal effects transform the ideal, stable entropy mode into an unstable continuum of highly localised modes: the thermal continuum. Applying this analysis to a gravitationally stratified atmosphere and coronal loops, reveals how thermal instability plays a role in the formation of coronal rain, and how it may fit in observed evaporation-condensation cycles in loops. Further including resistivity in current sheets reveals through a combination of linear analysis and non-linear simulations how a coupled tearing-thermal evolution leads to plasma condensation along flux ropes.