Recent Developments in Our Knowledge of Inner Magnetosphere‐Ionosphere Convection

Abstract

Plasma convection in the coupled inner magnetosphere‐ionosphere is influenced by different factors such as neutral winds, penetration electric fields, and polarization electric fields. Several crucial insights about the dynamics in the region have been derived by interpreting observations in conjunction with numerical simulations, and recent expansion in ground‐ and space‐based measurements in the region along with improvements in theoretical modeling has fueled renewed interest in the subject. In this paper we present a comprehensive review of the literature with an emphasis on studies since 2012 relevant to the National Science Foundation Geospace Environment Modeling program. We cover four specific areas: (1) the subauroral polarization stream, (2) penetration electric fields, (3) the disturbance dynamo, and (4) quiet time subauroral convection. We summarize new observations and resulting insights relevant to each of these topics and discuss various outstanding issues and unanswered questions.

Variability of the magnetospheric electric field due to high-speed solar wind convection from 1964 to 2009

“…Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License the E M field (Kivelson, 1976;He et al, 2010;Kunduri et al, 2018). These include the study of magnetospheric electric fields and their variation with geomagnetic activity, numerical simulations on the internal magnetosphere-ionosphere convection, the study of the small-scale magnetospheric electric field observed by the Double Star TC-1 satellite (Matsui et al, 2008;Kivelson, 1976).…”

“…Even today, only a few missions have included direct measurements of the magnetospheric electric field in high latitude regions such as the -Parker Solar Probe‖ mission launched on August 12, 2018 in Florida and -ESA S SMILE‖ class mission whose launch is scheduled for 2023. Therefore, many studies used data from the electric field on one hand and the magnetic field on the other hand, acquired at high latitudes (Kim et al, 2013;Kunduri et al, 2018) and at latitudes equatorial (Kelley et al, 1979;Fejer and Scherliess, 1995;Fejer et al, 2007). Since there is no way to determine directly the E M field overall distribution, various empirical and mathematical models have been provisionally constructed, with varying degrees of complexity (Wu et al, 1981;Pierrard et al, 2008;Matsui et al, 2013).…”

Duskside Sub‐Auroral Polarization Streams (SAPS) and Dawnside Subauroral Flows During the Magnetically Quiet 24 November and Moderately Active 25–27 November 2008

“…The second characteristic includes the rapid SW and IMF oscillations leading to IEF E Y oscillations and implying prevailing undershielding conditions due to the shielding E field's disturbed development (Kunduri et al., 2018). As shown in Figures 1a and 1b, the IEF E Y component oscillated between dawn‐to‐dusk ( E Y > 0 at southward IMF) and dusk‐to‐dawn ( E Y < 0 at northward IMF).…”

Influence of Atmospheric Circulation on Orientation of Auroral Arcs

“…For modeling the orientation of the arcs during spring transitions, we would need data of neutral winds above 100 km, but we have no such data. In general, the neutral wind at these altitudes is poorly known (Kunduri et al., 2018). Obviously, the wind at 100–150 km may differ crucially from that measured at 90–100 km.…”

“…The electric field generated due to the dynamo processes depends on the neutral winds and distribution of ionospheric conductivity or electron density at 100–150 km. Unfortunately, we have no co‐located measurements of neutral winds above 100 km and, in general, one lacks enough such data because of difficulty of observations in this region (Kunduri et al., 2018). In the present paper, therefore, we may only qualitatively hypothesize how the neutral wind influences the ionosphere‐magnetosphere system.…”