TY - JOUR
T1 - Vortex Generation and Auroral Response to a Solar Wind Dynamic Pressure Increase
T2 - Event Analyses
AU - Zhao, Jinyan
AU - Shi, Quanqi
AU - Tian, Anmin
AU - Shen, Xiao‐Chen
AU - Weygand, James M
AU - Wang, Huizi
AU - Yao, Shutao
AU - Ma, Xiao
AU - Degeling, Alexander William
AU - Rae, I. Jonathan
AU - Zhang, Hui
AU - Zhang, Xiao‐Jia
AU - Bai, Shi‐Chen
AU - Shang, Wensai
AU - Park, Jong‐Sun
N1 - Funding information:
This work was supported by the National Natural Science Foundation of China (Grants 41731068, 41774172, 41974189, 41941001, and 41961130382) and the Royal Society Newton Advanced Fellowship NAF\R1\191047, the Specialized Research Fund for State Key Laboratories, the young scholar plan of Shandong University at Weihai (2017WHWLJH08).
PY - 2021/3
Y1 - 2021/3
N2 - In this study, we investigate ionospheric responses, including currents and aurorae, to solar wind dynamic pressure (SW Pdyn) sudden increases, which are critical for understanding solar wind‐magnetosphere‐ionosphere coupling. We focus on two similar SW Pdyn pulse events that occurred on 24 January 2012 and 12 November 2010. In both cases, equivalent ionospheric currents (EIC) vortices were generated within about ten minutes after the pressure pulse arrival, with a counter‐clockwise rotating vortex (viewed from above) observed on the dusk side in the former case, and a clockwise vortex observed on the dawn side in the latter. Simultaneous ground‐based All‐Sky Imager (ASI) observations in the vicinity of the observed EIC vortex in each case showed that aurorae intensified on the dusk side, and diminished on the dawn side. These observations provide direct evidence of the scenario proposed byShi et al. (2014) that magnetospheric flow vortices generated by a solar wind pressure pulse carry field‐aligned currents into the ionosphere and thereby modulate auroral activity. The dawn/dusk asymmetry in the auroral intensification is a direct result of the opposite sense of vortex rotation on the dawn and dusk sides, which generate oppositely directed field‐aligned currents into/out of the ionosphere.
AB - In this study, we investigate ionospheric responses, including currents and aurorae, to solar wind dynamic pressure (SW Pdyn) sudden increases, which are critical for understanding solar wind‐magnetosphere‐ionosphere coupling. We focus on two similar SW Pdyn pulse events that occurred on 24 January 2012 and 12 November 2010. In both cases, equivalent ionospheric currents (EIC) vortices were generated within about ten minutes after the pressure pulse arrival, with a counter‐clockwise rotating vortex (viewed from above) observed on the dusk side in the former case, and a clockwise vortex observed on the dawn side in the latter. Simultaneous ground‐based All‐Sky Imager (ASI) observations in the vicinity of the observed EIC vortex in each case showed that aurorae intensified on the dusk side, and diminished on the dawn side. These observations provide direct evidence of the scenario proposed byShi et al. (2014) that magnetospheric flow vortices generated by a solar wind pressure pulse carry field‐aligned currents into the ionosphere and thereby modulate auroral activity. The dawn/dusk asymmetry in the auroral intensification is a direct result of the opposite sense of vortex rotation on the dawn and dusk sides, which generate oppositely directed field‐aligned currents into/out of the ionosphere.
UR - https://www.scopus.com/pages/publications/85103271317
U2 - 10.1029/2020ja028753
DO - 10.1029/2020ja028753
M3 - Article
SN - 2169-9380
VL - 126
JO - Journal of Geophysical Research: Space Physics
JF - Journal of Geophysical Research: Space Physics
IS - 3
M1 - e2020JA028753
ER -