Abstract
AbstractWhile nightside subauroral proton aurora shows rapid temporal variations, the cause of this variability has rarely been investigated. Using well‐coordinated observations by the Time History of Events and Macroscale Interactions during Substorms (THEMIS) all‐sky imagers, THEMIS satellites in the equatorial magnetosphere, and the low‐altitude NOAA 17 satellite, we examined the rapid temporal evolution of subauroral proton aurora in the premidnight sector. An isolated proton aurora occurred soon after an auroral poleward boundary intensification that was followed by an auroral streamer reaching the equatorward boundary of the auroral oval. Three THEMIS satellites in the magnetotail detected flow bursts and one of the THEMIS satellites in the outer plasmasphere observed a ring current injection together with electromagnetic ion cyclotron wave intensifications. Proton auroral brightenings occurred multiple times throughout the storm main phase and a majority of those were correlated with auroral streamers reaching the auroral equatorward boundary. This sequence highlights the important role of transient flow bursts and particle injections for plasma transport into the inner magnetosphere and thus reflects a tail‐inner magnetospheric interaction process in which transient flow bursts play an important role in injecting ring current ions into the plasmasphere, causing rapid modulation of precipitation and the resultant subauroral proton aurora.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.