Identifying the magnetospheric driver of STEVE
Abstract
For the first time, we identify the magnetospheric driver of STEVE, east-west aligned narrow emissions in the subauroral region. In the ionosphere, STEVE is associated with subauroral ion drift (SAID) features of high electron temperature peak, density gradient, and strong westward ion flow. In this study, we present STEVE's magnetospheric driver region at a sharp plasmapause containing: strong tailward quasi-static electric field, kinetic Alfven waves, parallel electron acceleration, perpendicular ion drift. The observed continuous emissions of STEVE are possibly caused by ionospheric electron heating due to heat conduction and/or auroral acceleration process powered by Alfven waves, both driven by the observed equatorial magnetospheric processes. The observed green emissions are likely optical manifestations of electron precipitations associated with wave structures traveling along the plasmapause. The observed SAR arc at lower latitudes likely corresponds to the formation of low-energy plasma inside the plasmapause by Coulomb collisions between ring current ions and plasmaspheric plasma.
Keywords
Cite
@article{arxiv.1906.08886,
title = {Identifying the magnetospheric driver of STEVE},
author = {Xiangning Chu and David Malaspina and Bea Gallardo-Lacourt and Jun Liang and Laila Andersson and Qianli Ma and Anton Artemyev and Jiang Liu and Bob Ergun and Scott Thaller and Hassanali Akbari and Hong Zhao and Brian Larsen and Geoffrey Reeves and John Wygant and Aaron Breneman and Sheng Tian and Martin Connors and Eric Donovan and William Archer and Elizabeth A. MacDonald},
journal= {arXiv preprint arXiv:1906.08886},
year = {2019}
}
Comments
Presentation for AGU Fall meeting 2018 on December 12, 2018