[en] The main ultraviolet auroral emission at Saturn consists of multiple structures forming a discontinuous ring of emission around the poles, occasionally organized in a global spiral. We present continuous observation of an auroral spiral rotating at ~85% of rigid corotation during several hours. Simultaneously, energetic neutral atom (ENA) emissions revealed a hot magnetospheric plasma population located in the same local time sector as the ends of the rotating spiral. Following plasma theory, we propose that pressure gradients induced by the energized plasma distorted the magnetospheric current system, resulting in the spiral morphology of the aurora. The rotating hot plasma was several times re-energized in the dusk sector during at least two days, generating a long-lasting auroral spiral. The ultraviolet spiral, the ENA emissions and the ions revealed by this multi-instrument dataset are three signatures of a magnetosphere-ionosphere coupling current system and of the associated hot plasma population rotating around Saturn.
Research Center/Unit :
STAR - Space sciences, Technologies and Astrophysics Research - ULiège
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Palmaerts, Benjamin ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Yao, Zhonghua ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Sergis, N.; Office of Space Research and Technology, Academy of Athens, Greece
Guo, Ruilong ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Grodent, Denis ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Dialynas, K.; Office of Space Research and Technology, Academy of Athens, Greece
Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Département d'astrophys., géophysique et océanographie (AGO)
Mitchell, D. G.; Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, USA
Language :
English
Title :
A long-lasting auroral spiral rotating around Saturn’s pole
Publication date :
2020
Journal title :
Geophysical Research Letters
ISSN :
0094-8276
eISSN :
1944-8007
Publisher :
Wiley, Washington, United States - District of Columbia
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