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

Abstract

During geomagnetic storms and substorms, the magnetosphere and ionosphere are strongly coupled by precipitating magnetospheric electrons from the Earth's plasma sheet and driven by both magnetospheric and ionospheric processes. Magnetospheric wave activity initiates electron precipitation, and the ionosphere and upper atmosphere further facilitate this process by enhancing the value of precipitated energy fluxes via connection of two magnetically conjugate regions and multiple atmospheric reflections. 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 17 March 2013 geomagnetic storm and their effects on the inner magnetospheric electric field and ring current. Our study is based on the magnetically and electrically self‐consistent Rice Convection Model‐Equilibrium of the inner magnetosphere with SuperThermal Electron Transport modified electron energy fluxes that take into account the electron energy interplay between the two magnetically conjugate ionospheres. SuperThermal Electron Transport‐modified energy flux in the Rice Convection Model‐Equilibrium leads to a significant difference in the global conductance pattern, ionospheric electric field formation, Birkeland current structure, ring current energization and its energy content, subauroral polarization drifts intensifications and their spatial locations, interchange instability redistribution, and overall energy interplay on the global scale.

The Case for Improving the Robinson Formulas

“…These correction factors are between 1.3 and 2.3, increasing with the characteristic energy of the initially precipitating electrons. Building on the Chen et al (2019) modeling results, these correction factors have been used by Khazanov et al (2019) within a kinetic drift physics approach, showing enhanced injection into the inner magnetosphere due to the higher conductance in the midlatitude nightside region.…”

Dynamical Properties of Peak and Time‐Integrated Geomagnetic Events Inferred From Sample Entropy

“…Second, a decrease of SampEn(Dst) marks a surge of organization/complexity in the ring current dynamics. It is probably due to the organization of the enhanced ring current itself, as well as to the partial feedback from various loss or mitigation mechanisms that start operating within the inner magnetosphere-ionosphere system, hindering further ring current enhancements (Daglis et al, 1999;Ganushkina et al, 2015;Khazanov et Liemohn, 2016). The fast increase of organization/complexity in the ap time series during storms should similarly correspond to a global structuring of field-aligned currents flowing near the equatorial inner boundary of the convection region, over the course of successive substorm expansions and through the mediation of different loss and feedback mechanisms driven by wave-induced particle precipitation and the resulting strong variations in ionospheric conductivity (Khazanov et al, 2019;Liou et al, 2001;Lysak, 1990;Ridley et al, 2004;Zhang & Paxton, 2008).…”

“…Third, the different variations of Dst and ap dynamical complexities are not inconsistent with the present knowledge of the various processes involved during disturbed geomagnetic conditions. During moderate to strong geomagnetic storms, very fast injections of energetic ions and electric fields can transiently penetrate down to middle and even low latitudes within narrow channels, in the form of subauroral polarization streams (SAPS) or subauroral ion drifts (SAID), appearing during substorm onsets (AE increases) and adding an irregular and stochastic contribution to the ring current (Gonzales et al, 1983;Khazanov et al, 2019;Mishin et al, 2017;Soraas et al, 2004). A significant contribution to Dst from such fast injections, well quantified by the partly stochastic AE index, could possibly prevent Dst entropy from decreasing as fast as ap entropy.…”

“…Such a stochastic component may arise from stochastic processes taking place at high auroral latitudes near the foot of geomagnetic field lines, such as ionospheric conductivity variations and ion outflows, that can strongly disturb both the field-aligned currents measured on the Earth and the development of susbtorms and injections in the tail (Khazanov et al, 2019;Welling & Liemohn, 2016). It could also be due to stochastic phenomena occurring in the magnetotail, such as reconnection processes and wave-particle interactions that perturb field-aligned currents inside the auroral oval (Borovsky et al, 1993;Daglis et al, 1999;Hesse et al, 2014;Khazanov et al, 2019;Liou et al, 2001;Liu et al, 2013;Lysak, 1990;Sharma et al, 2008). As the corresponding injections of currents, fields, and energetic particles flow toward the Earth through various channels, they can merge, and their individual effects may blend into more regular structures, averaging out to a much less stochastic dynamics that only retains the initial impact P * of the solar wind on the magnetosphere.…”

“…As the corresponding injections of currents, fields, and energetic particles flow toward the Earth through various channels, they can merge, and their individual effects may blend into more regular structures, averaging out to a much less stochastic dynamics that only retains the initial impact P * of the solar wind on the magnetosphere. The physical processes occurring from the inner auroral boundary down to subauroral regions may also provide sufficient feedbacks (Daglis et al, 1999;Khazanov et al, 2019;Liou et al, 2001;Lysak, 1990;Welling & Liemohn, 2016) to ensure a tighter dynamical organization in this zone, thereby reducing the amplitude of random fluctuations. As a result, the stochastic component arising from the preceding (in space and time) local processes can become minor near the inner edge of the auroral zone (in ap measurements) as well as further inward in ring current dynamics (in Dst measurements), as compared with a regular, non-stochastic component better correlated with solar wind driving (P * ).…”