Magnetic reconnection is an important physical process with the topological change of the magnetic field lines and the conversion of magnetic energy into plasma kinetic energy (

Asymmetric magnetic reconnection usually occurs at the Earth’s magnetopause, where the magnetic field strength and plasma density are different between the magnetosheath and magnetosphere. In this paper, a two-dimensional particle-in-cell simulation model is used to study the energy conversion during asymmetric magnetic reconnection. Energy conversion can occur in the vicinity of the X-line, magnetosphere separatrix region, and reconnection fronts. In the vicinity of the X-line and magnetosphere separatrix region, the electromagnetic field energy is mainly transferred to electrons, while at the reconnection fronts, the electromagnetic field energy is mainly transferred to ions. For the case with weak magnetic field asymmetry, the reconnection fronts dominate the energy conversion, which is related to the inflowing Poynting flux S z at the fronts. For the case with strong magnetic field asymmetry, the energy conversion occurs around the X-line and magnetosphere separatrix region, but no longer at the reconnection fronts. This is because the inflowing Poynting flux S x near the magnetosphere separatrices provides electromagnetic energy for energy conversion. The density asymmetry has no significant effect on the spatial distribution of the energy conversion.

Using 2D particle-in-cell (PIC) simulations, the generation of electrostatic solitary waves (ESWs) and the associated plasma waves in symmetric magnetic reconnection are studied, and multiple kinds of ESWs with different propagating speeds are identified. Near the current sheet in the outflow region, there are two kinds of ESWs propagating away from the X line: their propagating speeds are about 0.73V Te0 and 1.2V Te0 (where V Te0 is the initial electron thermal velocity), and their generation is associated with the Buneman instability and the electron two-stream instability, respectively. In the separatrix region, there is one kind of ESW propagating toward the X line with a propagating speed of about 1.2 V Te0, which is formed during the nonlinear evolution of the electron two-stream instability. We also run a case with a guide field, and there exist two kinds of ESWs: the ESWs propagating away from the X line can be generated near the separatrices with electron outflow, while the ESWs propagating toward the X line can be generated near the separatrices with electron inflow. The two kinds of ESWs are associated with the electron two-stream instability and the Buneman instability, respectively.