Data-driven Fully Kinetic Simulations of Magnetic Reconnection in Earth’s Magnetotail

Magnetic reconnection is an energy conversion process that accelerates particles to high energies. This explosive process occurs in near-Earth space as well as in many other astrophysical environments. While direct measurements of plasma parameters, including particle energy distributions, are often not possible, Earth’s magnetosphere is one of the few natural laboratories where such observations can be made. However, satellite observations are limited in spatial and temporal coverage, whereas simulations can offer a more comprehensive view of the reconnection process. Thus, we want to bridge both techniques and use kinetic simulations initialized with observational constraints.   

We present fully kinetic simulations of magnetic reconnection in Earth’s magnetotail, using parameters derived from a well-studied event observed by the Magnetospheric Multiscale (MMS) mission. The simulations are performed using the energy-conserving particle-in-cell (PIC) code ECsim/RelSIM, which includes both ion and electron dynamics to investigate particle energization during reconnection. We investigate the impact of initial plasma conditions and numerical parameters on the resulting energy distributions, and compare the simulation outputs with in-situ observations to assess the simulations’ ability to reproduce key features of the event. This work presents a comparison of particle energy distributions between fully kinetic simulations and spacecraft observations for a magnetotail reconnection event.