Bibliography

Global Effects of a Polar Solar Eclipse on the Coupled Magnetosphere-Ionosphere System

It is well-known that solar eclipses can significantly impact the ionosphere and thermosphere, but how an eclipse influences the magnetosphere-ionosphere system is still unknown. Using a coupled magnetosphere-ionosphere-thermosphere model, we examined the impact on geospace of the northern polar-region eclipse that occurred on June 10, 2021. The simulations reveal that the eclipse-induced reduction in polar ionospheric conductivity causes large changes in field-aligned current, cross-polar cap potential and auroral activity. While such effects are expected in the northern hemisphere where solar obscuration occurred, they also occurred in the southern hemisphere through electrodynamic coupling. Eclipse-induced changes in monoenergetic auroral precipitation differ significantly between the northern hemisphere and southern hemisphere while diffuse auroral precipitation is interhemispherically symmetric. This study demonstrates that the geospace response to a polar-region solar eclipse is not limited just to the eclipse region but has global implications.

Chen, Xuetao; Dang, Tong; Zhang, Binzheng; Lotko, William; Pham, Kevin; Wang, Wenbin; Lin, Dong; Sorathia, Kareem; Merkin, Viacheslav; Luan, Xiaoli; Dou, Xiankang; Luo, Bingxian; Lei, Jiuhou;

Published by: Geophysical Research Letters      Published on:

YEAR: 2021     DOI: 10.1029/2021GL096471

auroral activity; magnetosphere-ionosphere coupling; polar solar eclipse

Ionospheric response at conjugate locations during the 7—8 September 2017 geomagnetic storm over the Europe-African longitude sector

This paper focuses on unique aspects of the ionospheric response at conjugate locations over Europe and South Africa during the 7–8 September 2017 geomagnetic storm including

Habarulema, John; Katamzi-Joseph, Zama; a, Dalia; Nndanganeni, Rendani; Matamba, Tshimangadzo; Tshisaphungo, Mpho; Buchert, Stephan; Kosch, Michael; Lotz, Stefan; Cilliers, Pierre; , others;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2020     DOI: 10.1029/2020JA028307

Solar filament impact on 21 January 2005: Geospace consequences

On 21 January 2005, a moderate magnetic storm produced a number of anomalous features, some seen more typically during superstorms. The aim of this study is to establish the differences in the space environment from what we expect (and normally observe) for a storm of this intensity, which make it behave in some ways like a superstorm. The storm was driven by one of the fastest interplanetary coronal mass ejections in solar cycle 23, containing a piece of the dense erupting solar filament material. The momentum of the massive solar filament caused it to push its way through the flux rope as the interplanetary coronal mass ejection decelerated moving toward 1 AU creating the appearance of an eroded flux rope (see companion paper by Manchester et al. (2014)) and, in this case, limiting the intensity of the resulting geomagnetic storm. On impact, the solar filament further disrupted the partial ring current shielding in existence at the time, creating a brief superfountain in the equatorial ionosphere\textemdashan unusual occurrence for a moderate storm. Within 1 h after impact, a cold dense plasma sheet (CDPS) formed out of the filament material. As the interplanetary magnetic field (IMF) rotated from obliquely to more purely northward, the magnetotail transformed from an open to a closed configuration and the CDPS evolved from warmer to cooler temperatures. Plasma sheet densities reached tens per cubic centimeter along the flanks\textemdashhigh enough to inflate the magnetotail in the simulation under northward IMF conditions despite the cool temperatures. Observational evidence for this stretching was provided by a corresponding expansion and intensification of both the auroral oval and ring current precipitation zones linked to magnetotail stretching by field line curvature scattering. Strong Joule heating in the cusps, a by-product of the CDPS formation process, contributed to an equatorward neutral wind surge that reached low latitudes within 1\textendash2 h and intensified the equatorial ionization anomaly. Understanding the geospace consequences of extremes in density and pressure is important because some of the largest and most damaging space weather events ever observed contained similar intervals of dense solar material.

Kozyra, J.; Liemohn, M.; Cattell, C.; De Zeeuw, D.; Escoubet, C.; Evans, D.; Fang, X.; Fok, M.-C.; Frey, H.; Gonzalez, W.; Hairston, M.; Heelis, R.; Lu, G.; Manchester, W.; Mende, S.; Paxton, L.; Rastaetter, L.; Ridley, A.; Sandanger, M.; Soraas, F.; Sotirelis, T.; Thomsen, M.; Tsurutani, B.; Verkhoglyadova, O.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 07/2014

YEAR: 2014     DOI: 10.1002/2013JA019748

cold dense plasma sheet; Equatorial anomaly; magnetotail; precipitation; prompt penetration electric field; solar filament