Authors: Xianyu Liu (Umich), Spiro K. Antiochos (Umich), Nishtha Sachdeva (Umich), Gábor Tóth (Umich), Ward B. Manchester IV (Umich), Bart van der Holst (BU), Igor Sokolov (Umich), Tamas Gombosi (Umich), Lulu Zhao (Umich)

Energy-conservative treatments have appeared in recent simulations of solar coronal mass ejections (CMEs). This work conducts a controlled comparison of CME simulations using conservative and non-conservative schemes for the energy equation based on the Alfv\’en Wave Solar atmosphere Model (AWSoM). We simulate an ideal CME event originating from a simple and symmetric active region. We obtained three simulations by manipulating the choice of numerical schemes while keeping other settings identical. We find a factor $>2$ difference in the final kinetic energy between energy-conservative and non-conservative simulations. The increase in thermal energy is comparable to the increase in kinetic energy in the conservative simulation. Our analysis reveals that the flare reconnection and increase of kinetic energy terminate earlier with the non-conservative scheme. We found that thermodynamics plays a critical role in the flare reconnection. The thermal pressure gradient in the current sheet impedes reconnection. Our results suggest that exploring energy-conservative treatments in CME simulations is meaningful for space weather studies and investigations of the CME energy budget problem.