The effect of ring current electron scattering rates on magnetosphere-ionosphere coupling

<p>This simulation study investigated the electrodynamic impact of varying descriptions of the diffuse aurora on the magnetosphere-ionosphere (M-I) system. Pitch angle diffusion caused by waves in the inner magnetosphere is the primary source term for the diffuse aurora, especially during storm time. The magnetic local time (MLT) and storm-dependent electrodynamic impacts of the diffuse aurora were analyzed using a comparison between a new self-consistent version of the Hot Electron Ion Drift Integrator with varying electron scattering rates and real geomagnetic storm events. The results were compared with <em>D</em><em>s</em><em>t</em> and hemispheric power indices, as well as auroral electron flux and cross-track plasma velocity observations. It was found that changing the maximum lifetime of electrons in the ring current by 2\textendash6\&nbsp;h can alter electric fields in the nightside ionosphere by up to 26\%. The lifetime also strongly influenced the location of the aurora, but the model generally produced aurora equatorward of observations.</p>