Kinetic Alfven Waves in the Global Coupling Associated with Fast Flows

Shear Alfven waves are fundamentally important in space plasmas. Kinetic Alfven waves (KAWs) are shear Alfven waves possessing short perpendicular wavelength that is comparable to the ion gyroradius, k ⊥ ρ i ~ 1, where k ⊥ is the perpendicular wave number and ρ i is the ion Larmor radius. KAWs can develop parallel electric fields that facilitates particle heating and transport on scales where the ion motion decouples from magnetic field lines. In this study, we use the Auburn Global Hybrid Code in 3-Dimensions (ANGIE3D) to investigate the generation of kinetic Alfven waves (KAWs) in the Earth’s magnetotail. Transport of these KAWs to the ionosphere is illustrated in a comprehensive manner on the global scale. In the hybrid code, ions are treated as fully kinetic particles, while electrons are treated as a massless fluid. Our global hybrid simulation results show that KAWs are generated in magnetic reconnection in the tail plasma sheet, located around fast flows. We identify the KAWs by their dispersion relation and polarization, with a turbulent spectrum and ion beating. The resulting KAWs are compared with those generated in local-scale hybrid simulations of reconnection in slab geometry.