HR: 14:25h
AN: SM13E-04    [Abstracts]
TI: Ring current auroras
AU: * Zhang, Y
EM: yongliang.zhang@jhuapl.edu
AF: Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, United States
AU: Paxton, L J
EM: larry.paxton@jhuapl.edu
AF: Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, United States
AU: Zheng, Y
EM: yihua.zheng@jhuapl.edu
AF: Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, United States
AB: Ring current auroras (RCA) refer to the auroral emissions due to precipitating particles from the ring current. RCA are typically observed at sub-auroral latitudes due to precipitating protons or energetic neutral atomic hydrogen via charge-exchange. The electromagnetic ion cyclotron wave - particle interaction is the dominant mechanism for the precipitating protons. Change in the ambient magnetic field along the proton drift path could also cause the proton to precipitate. Different features of RCA will be shown by examples. A limited ring current simulation indicates that the structures in RCA are controlled by the proton pitch angle distribution. Observations of RCA not only reveal ring current dynamics but also serve as a tool to validate ring current models.
DE: 0310 Airglow and aurora
DE: 2407 Auroral ionosphere (2704)
DE: 2471 Plasma waves and instabilities (2772)
DE: 2716 Energetic particles: precipitating
DE: 2778 Ring current
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting