Numerical Simulations of Chromospheric Microflares

Abstract

With gravity, ionization, and radiation being considered, we perform 2.5D compressible resistive MHD simulations of chromospheric magnetic reconnection using the CIP-MOCCT scheme. The temperature distribution of the quiet-Sun atmospheric model VALC and the helium abundance (10%) are adopted. Our 2.5D MHD simulation reproduces qualitatively the temperature enhancement observed in chromospheric microflares. The temperature enhancement $\Delta T$ is demonstrated to be sensitive to the background magnetic field, whereas the total evolution time $\Delta t$ is sensitive to the magnitude of the anomalous resistivity. Moveover, we found a scaling law, which is described as $\Delta T/\Delta t \sim {n_H}^{-1.5} B^{2.1} {\eta_0}^{0.88}$. Our results also indicate that the velocity of the upward jet is much greater than that of the downward jet and the X-point may move up or down.