Improving Space Weather Forecasts By Including the Effects of Farley-Buneman Instability in Global Simulations of Geospace

Space weather forecasts can be made using coupled models of the geospace system.  The combination of the Lyon-Fedder-Mobarry  (LFM) global geospace simulation with the Rice Convection Model (RCM) provides a powerful tool for modeling the system, especially during geomagnetic storms.    The LFM combines a magnetohydrodynamic (MHD) simulation of the magnetosphere with a 2D electrostatic solution of the ionosphere.  The RCM uses drift physics to accurately model the inner magnetosphere, including the ring current that is enhanced during geomagnetic storms.   The LFM and coupled LFM-RCM simulations have previously shown high cross polar cap potentials during strong solar wind driving conditions.  We have implemented a module for the ionospheric calculation in the LFM that includes modifications to the ionospheric conductivity driven by the Farley-Bueneman instability (FBI).  These effects include anomalous electron heating and non-linear DC current enhancements of the conductivity in regions of strong electric fields.  Using an improved version of the LFM-RCM model capable of handling dipole tilts and asymmetric ionospheric solutions we have tested the impact of including FBI effects by simulation the 17 March 2013 geomagnetic storm.  In these simulations we observed significant reductions in the cross polar cap potential during the strongest driving conditions, significant increases in the ionospheric conductivity in the auroral oval, and better DMSP observations of sub-auroral polarization streams.