Magnetosphere-Ionosphere Coupling Effects on Inner Magnetospheric Electric Fields During Storms: RCM-E and Van Allen Probe Comparisons

Abstract:

Storm-associated enhancements in the typically duskward large-scale (> 1 R_E) convection electric field play an important role in the formation and development of the ring current and plasmasphere. Observations have shown that electric field enhancements can occur at low L < 3 within the plasmasphere and that the electric field is stronger on the duskside than dawnside (e.g., Rowland and Wygant, 1998, Califf et al., 2015; Thaller et al., 2015). We investigate the development of observed stormtime features of the electric field through self-consistent inner magnetospheric-ionospheric transport and electrodynamics. Our approach is to compare electric field intensity from simulations and Van Allen Probes/EFW measurements during a few storms. We use the magnetically and electrically self-consistent Rice Convection Model – Equilibrium (RCM-E) of the inner magnetosphere. The primary diffuse precipitating differential electron fluxes are computed using parameterized rates of whistler-generated and plasmaspheric hiss electron pitch-angle scattering in the RCM-E. The Super Thermal Electron Transport (STET) model, that computes all sources and collisional processes in the ionosphere and inner magnetosphere, is used to modify the RCM-E precipitating electron fluxes to account for multiple atmospheric reflections of electrons between conjugate hemispheres. The precipitating electron flux affects the ionospheric conductance that influences the electric field. We will compare the simulated and observed electric field, assess the source of discrepancies, and investigate how the transport of ring current particles and magnetosphere-ionosphere coupling controls and affects the spatial and temporal structure of the electric field.