On the Causes of Plasmoid Acceleration and the Change of Magnetic Reconnection Rate in a Resistive MHD Simulation

Prominence/filament eruptions and coronal mass ejections (CMEs) usually show an initial acceleration followed by a nearly constant propagation speed. The magnetic reconnection rate deduced from the photospheric and chromospheric signatures are well-correlated with the acceleration of filament/CME. Namely, the reconnection rate increases rapidly and then decreases slowly, while the acceleration of filament/CME shows the similar behavior during the same time interval. In this study, a two-dimensional resistive magnetohydrodynamic simulation is carried out to study the mutual dependence between the plasmoid acceleration and the reconnection rate. Our results show that the change of plasmoid acceleration is always slightly ahead of the change of reconnection rate. Therefore, this report will focus on what controls the change of plasmoid acceleration and why the change of plasmoid acceleration can lead to the change of reconnection rate. The plasmoid acceleration will be examined based on force balance analysis. The reason why the ejection of the plasmoid can reduce the magnetic reconnection rate will also be discussed.