Field Line Resonances in the BATSRUS Global Magnetospheric Model

Abstract:

Wave-mode coupling in Earth's magnetosphere is an important energy transfer mechanism and plays a major role in radiatian belt, magnetic reconnection, and auroral phenomena. We investigate signatures of field line resonances using the BATSRUS global magnetospheric model by using a synthetic solar wind driver with imbedded broadband dynamic pressure fluctuations to drive fast-mode magnetosonic waves into the inner magnetosphere. We find that BATSRUS produces a corresponding multi-harmonic continuum of toroidal field line resonances in the dayside, which show an amplitude peak and roughly 180 degree phase reversal across the resonant L shells. This demonstration of BATSRUS's ability to reproduce FLRs in the magnetosphere is an important step in self-consistently modeling ultra-low frequency wave dynamics in BATSRUS.