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Mid-latitude plasma bubble over China and adjacent areas during a magnetic storm on 08 September 2017

space weather
Volume16, Issue3

Ercha Aa;Wengeng Huang;Siqing Liu;Aaron Ridley;Shasha Zou;Liqin Shi;Yanhong Chen;Hua Shen;Tianjiao Yuan;Jianyong Li;Tan Wang
 
Abstract
This paper presents observations of postsunset super plasma bubbles over China and adjacent areas during the second main phase of a storm on 8 September 2017. The signatures of the plasma bubbles can be seen or deduced from (1) deep field‐aligned total electron content depletions embedded in regional ionospheric maps derived from dense Global Navigation Satellite System networks, (2) significant equatorial and midlatitudinal plasma bite‐outs in electron density measurements on board Swarm satellites, and (3) enhancements of ionosonde virtual height and scintillation in local evening associated with strong southward interplanetary magnetic field. The bubbles/depletions covered a broad area mainly within 20°–45°N and 80°–110°E with bifurcated structures and persisted for nearly 5 hr (∼13–18 UT). One prominent feature is that the bubbles extended remarkably along the magnetic field lines in the form of depleted flux tubes, reaching up to midlatitude of around 50°N (magnetic latitude: 45.5°N) that maps to an altitude of 6,600 km over the magnetic equator. The maximum upward drift speed of the bubbles over the magnetic equator was about 700 m/s and gradually decreased with altitude and time. The possible triggering mechanism of the plasma bubbles was estimated to be storm time eastward prompt penetration electric field, while the traveling ionospheric disturbance could play a role in facilitating the latitudinal extension of the depletions.
 
原文链接:
                   http://iopscience.iop.org/article/10.3847/1538-4357/aa9075/meta
                   http://ir.nssc.ac.cn/handle/122/6070