Simulations of Ionospheric Precipitation Effects on Reconnection Rate, Cross Polar Cap Potential Saturation, and Viscous Interaction

Using OpenGGCM simulations for several case studies we artificially scale the precipitation into the ionosphere, and analyze the effects from changes in ionospheric conductivity. We focus on resultant changes to the reconnection rate, the cross polar cap potential (CPCP) saturation, and the viscous interaction. We find that for increased precipitation the cross polar cap potential is decreased, and vice versa. However, using the Hesse-Forbes-Birn method to find the reconnection rate, we find that the reconnection rate does not depend strongly on the ionospheric conductivity, i.e., there are differences between the reconnection rate and the CPCP. Specifically, for periods when precipitation is artificially increased by an order of magnitude during strong driving, the CPCP is lower than the reconnection rate, in some cases by as much as by 50%. We attribute this to the CPCP saturation effect. By contrast, when the precipitation is significantly decreased during periods of strong solar wind driving, the CPCP is higher than the reconnection rate by up to 30%. In these situations, viscous interaction significantly contributes to the ionospheric potential.