Application of GPU-accelerated Particle-in-cell Simulations in Magnetic Reconnection Associated with Energy Conversion between Field and Particles

Magnetic reconnection is a fundamental physical process of rapidly converting magnetic energy into particles in space physics. The electron diffusion region (EDR), which can be split into the inner EDR and outer EDR, is the crucial region during magnetic reconnection. The inner EDR, where the magnetic field is dissipated, is responsible for the heating and acceleration of the electrons. The outer EDR also plays a crucial role where the electrons are decelerated and return the energy to the magnetic field in the pileup region behind the reconnection front (RF). Here we present the studies associated with energy conversions around EDR using fully kinetic particle-in-cell (PIC) simulations of advanced GPU-accelerated computing and Magnetospheric Multiscale (MMS) mission observations. It is found that part of the electrons in the outer EDR are forced backward to the inner EDR by the magnetic tension force to be accelerated again, which we name it by magnetic Marangoni effect. And we also report a novel crater structure of magnetic field behind the RF caused by the continuous impact of the high-speed outflow electron jets. Our PIC simulation scheme based on the GPU architecture can achieve high performance computing and fast accessibility to the simulation results. The scientific findings in our studies propose various approaches for the particle acceleration and energy conversion during magnetic reconnection.