A new dynamic fluid-kinetic model for plasma transport in the plasmasphere

Wednesday, 17 December 2014
Yan Wang, Jiannan Tu and Paul Song, University of Massachusetts Lowell, Space Science Laboratory and Physics Department, Lowell, MA, United States
A new dynamic fluid-kinetic (DyFK) model is developed for investigating the plasma transport along a closed flux tube in the plasmasphere by coupling a truncated version of the field line interhemispheric plasma (FLIP) model at altitudes below 800 km and a generalized semi-kinetic (GSK) model above it with an overlapped boundary region (800 km-1100 km) in both hemispheres. The flux tube is allowed to move both radially away from the Earth and azimuthally around the Earth. Ion species O+ and He+ are for the first time treated as simulation particles in a numerical model for the plasmasphere. The simulation particles are subjected to the parallel electric field, magnetic mirror force, gravity, centrifugal force and Coulomb collisions, as well as possible wave-particle interaction. The effects of ionosphere-plasmasphere coupling on the day-night evolution of the plasmasphere and the relative abundance of O+ and He+ are studied. Simulations are also conducted to investigate the influence of wave-particle interaction on the field-aligned density distributions of ions (O+/ H+/ He+) and their velocity distributions.