Predicting Auroral Conductance in Global MHD Models for Extreme Events

Abstract:

The active interaction between the solar wind and the Earth’s magnetic field causes several electrical currents in the magnetosphere to emerge, some of which, like field aligned currents, close through the upper atmosphere. Since these currents close through the ionosphere of the Earth, the ionospheric conductance becomes an important quantity for predicting space weather effects on the ground. The accurate estimation of the ionospheric conductance due to auroral precipitation is a major challenge in most global magnetohydrodynamic (MHD) models used in predicting space weather. Because a fluid approach alone cannot accurately reproduce realistic particle precipitation patterns, empirical models are used to calculate the auroral conductance. In this study, we present preliminary comparisons between two such empirical models developed independently using different datasets - the Conductance Model for Extreme Events (CMEE), and the Auroral Precipitation and High Latitude Ionosphere Electrodynamics (AuroraPHILE) Model. These two conductance models have also been used within the Space Weather Modeling Framework (SWMF; Toth et al, 2005) to quantify improvements in space weather prediction using these empirical models. We compare various space weather indices and ionospheric measurements against observations for a quantified comparison between the advantages and disadvantages of both the models, while using their implementation in global MHD models to demonstrate the importance of accurate estimation of this quantity for improvements in present space weather prediction capabilities.