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

Abstract

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 Dst 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 2–6 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.

Conductance Model for Extreme Events: Impact of Auroral Conductance on Space Weather Forecasts

“…While a physics-based approach to precipitation has been applied in several global models (e.g. Raeder et al, 2001, Zhang et al, 2015, Yu et al, 2016, Perlongo et al, 2017 using kinetic theory (e.g. Knight, 1973), RIM uses a different and simpler approach to estimate the auroral conductance.…”

The Magnetosphere‐Ionosphere Electron Precipitation Dynamics and Their Geospace Consequences During the 17 March 2013 Storm

“…These empirical conductance formulae are widely used in the space science community in global models for magnetosphere-ionosphere processes (see, e.g., recent papers by Wolf et al, 2016, Wiltberger et al, 2016, and Perlongo et al, 2017, and we modify equation (2) here by taking into account SE MI coupling processes that redistribute energy fluxes and mean energies as shown in Figure 2. These empirical conductance formulae are widely used in the space science community in global models for magnetosphere-ionosphere processes (see, e.g., recent papers by Wolf et al, 2016, Wiltberger et al, 2016, and Perlongo et al, 2017, and we modify equation (2) here by taking into account SE MI coupling processes that redistribute energy fluxes and mean energies as shown in Figure 2.…”

Impact of Precipitating Electrons and Magnetosphere‐Ionosphere Coupling Processes on Ionospheric Conductance

“…RB1987 derived height‐integrated Pedersen and Hall conductances as a function of mean electron energy and total electron energy flux. These conductance formulas are widely used in the space science community in global models for magnetosphere‐ionosphere processes (see for example recent papers by Wolf et al (), Wiltberger et al (), and Perlongo et al ()). In deriving these conductances, RB1987 assumed Maxwellian distributions for the precipitating electrons.…”

“…For example, Wiltberger et al () assume Maxwellian distribution functions in the plasma reference frame (Pembroke et al, ) to estimate ionospheric conductances in MHD modeling using the Lyons‐Fedder‐Mobarry code. Similarly, Perlongo et al () applied these equations to the ring current electron populations that were calculated based on the bounce‐averaged kinetic approach by Liemohn et al ().…”