Cusp Ion Precipitation Associated with Magnetopause Reconnection: Global Hybrid Simulation of TRICE-2 Rocket Event*

We investigate the linkage between the magnetopause reconnection and cusp ion precipitation by conducting 3D global hybrid simulations using the Auburn Global Hybrid Code in 3D (ANGIE3D). The simulation is performed for the cusp event observed by the Twin Rocket Investigation of Cusp Electrodynamics-2 (TRICE-2) rockets in conjunction with an MMS magnetopause crossing (Fuselier et al., 2022, https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2022JA030354), under the condition of a southward interplanetary magnetic field (IMF) with a predominant B_y component. Multiple reconnection sites are present at the northern-dawn and southern-dusk sectors as well as lower latitudes. The corresponding cusp ion precipitation is recursive with a period of ~ minute around certain fixed latitudes. The global evolution of magnetopause reconnection, cusp location and size, and cusp ion precipitation are investigated. A detailed comparison between the simulated energy-latitude dispersive spectrum of cusp ions and the TRICE-2 in-situ observation is presented.