Effects of modeled ionospheric conductance and electron loss on self‐consistent ring current simulations during the 5–7 April 2010 storm

Abstract

We investigate the effects of different ionospheric conductance and electron loss models on ring current dynamics during the large magnetic storm of 5–7 April 2010 using the magnetically and electrically self‐consistent Rice Convection Model–Equilibrium (RCM‐E). The time‐varying RCM‐E proton distribution boundary conditions are specified using a combination of TWINS 1 and 2 ion temperature maps and in situ THEMIS and GOES spectral measurements in the plasma sheet. With strong electron pitch‐angle diffusion, the simulated equatorial ring current electron pressure is weak with (1) uniform conductance or (2) conductance based on parameters from the International Reference Ionosphere 2007 and the feedback of simulated precipitating electrons. With the Chen and Schulz electron loss model that includes strong diffusion in the plasma sheet and weak diffusion in the plasmasphere, the stormtime equatorial RCM‐E electron pressure is enhanced in the inner magnetosphere from midnight through dawn to the dayside. The enhancement extends to lower geocentric distance with uniform conductance than with the more realistic ionospheric conductance model due to electric field shielding effects. Electron losses affect not only the simulated electron pressures, but through magnetospheric‐ionospheric coupling, the redistributed electric and magnetic fields affect the ring current proton transport. The simulations reproduced features observed by in situ magnetic field and proton flux data, and TWINS global ENA observations. The simulated stormtime ring current energization can vary significantly depending on the ionospheric conductance and electron loss model used. Thus, it is important to incorporate realistic descriptions of ionospheric conductance and electron losses in inner magnetospheric models.

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

“…Changes to the hot electron drift paths will alter the trapped electron fluxes, while changes in the cold plasma evolution will alter the rate at which the trapped electron fluxes are converted into precipitating fluxes via pitch angle scattering by chorus and hiss waves. The version used at The Aerospace Corporation (Chen et al, 2012, Chen, Lemon, Orlova, et al, 2015, Chen, Lemon, Guild, et al, 2015, Chen et al, 2019 is different than the version used at Rice University (Yang et al, 2014, but the fundamental physics and much of the central code is the same. The RCM-E is a model of magnetospheric plasma drift, electrodynamic coupling with the ionosphere (Harel, 1981;Sazykin et al, 2002Sazykin et al, , 2005, and coupling between the plasma and magnetic field (Lemon, 2003, Lemon et al, 2004.…”

“…According to previous studies (e.g., Fu et al, 2001), the contribution of outflow oxygen ions from ionosphere to ring current formation becomes significantly more important when magnetic storms are more intense. RCM-E simulations have been able to account simultaneously for variations in observed magnetic intensity and trapped ion [Chen et al, 2012] and electron (Chen, Lemon, Guild, et al, 2015) fluxes. RCM-E simulations have been able to account simultaneously for variations in observed magnetic intensity and trapped ion [Chen et al, 2012] and electron (Chen, Lemon, Guild, et al, 2015) fluxes.…”

“…As has been shown by Khazanov et al (2014) about 15-40% of the total aurora energy returns back to the magnetosphere and the conjugate ionosphere. As discussed by Khazanov et al (2015), , 2017a, the first step in such simulations is initiation of electron precipitation from the Earth's plasma sheet via wave-particle interactions (WPIs) into both magnetically conjugate points (e.g., as is simulated by Chen, Lemon, Guild, et al, 2015). As discussed by Khazanov et al (2015), , 2017a, the first step in such simulations is initiation of electron precipitation from the Earth's plasma sheet via wave-particle interactions (WPIs) into both magnetically conjugate points (e.g., as is simulated by Chen, Lemon, Guild, et al, 2015).…”

“…As discussed by Khazanov et al (2015), , 2017a, the first step in such simulations is initiation of electron precipitation from the Earth's plasma sheet via wave-particle interactions (WPIs) into both magnetically conjugate points (e.g., as is simulated by Chen, Lemon, Guild, et al, 2015). Our study is based on the Aerospace version of the magnetically and electrically self-consistent Rice Convection Model-Equilibrium (RCM-E) of the inner magnetosphere (Chen, Lemon, Guild, et al, 2015), with STET-modified electron energy fluxes that take into account the electron energy interplay between the two magnetically conjugate ionospheres. This paper focuses on the resulting electron energy fluxes and affiliated height-integrated Pedersen and Hall conductances in the auroral regions produced by multiple atmospheric reflections during the large 17 March 2013 geomagnetic storm and their effects on the inner magnetospheric electric field and ring current.…”

Self‐Consistent Modeling of Electron Precipitation and Responses in the Ionosphere: Application to Low‐Altitude Energization During Substorms

“…Therefore, a self-consistent modeling of the MI system is required to investigate the global scale causes and effects in the MI system. In view of this, Chen, Lemon, Guild, et al (2015) included wave-induced diffusion processes in their ring current model Rice Convection Model Equilibrium (RCM-E) via energy-dependent electron loss rates due to plasma waves in the magnetosphere and reproduced good agreement of simulated and observed trapped and precipitating electrons (Chen, Lemon, Orlova, et al, 2015). The statistical nature of these empirical precipitation models precludes specification of small-scale, transient variations in both space and time.…”