Impact of auroral conductance on global ionospheric electrodynamics

Auroral energetic particle precipitation is the main cause of ionospheric conductivity at high latitudes, especially under geomagnetically disturbed conditions. Estimates of auroral conductance are very difficult due to the lack of observations with sufficient spatial coverage and temporal cadence. As a result, the global morphology of auroral conductance often relies on empirical models based on statistical observations taken over a long period of time. Though empirical models are very useful in representing the average distributions of auroral conductance, they are inadequate when applied to real events. In order to better represent the spatiotemporal variations of auroral conductance for specific events, it is highly desirable to improve the estimation of conductance by combining a set of dispersed observations through data assimilation. The Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure is specifically designed for obtaining the global snapshots of high-latitude ionospheric parameters, including Pedersen and Hall conductances, electric fields, horizontal and field aligned currents, by synthesizing various space- and ground-based observational data. This paper discusses how the different data sets can be used in AMIE to derive the global conductance patterns, with a special focus on how the different conductance distributions may subsequently affect the electric fields, currents, and Joule heating distributions in AMIE.