SM032-0010
Chorus acceleration in extremely L-shell, electron filling and proton loss during storm of August 2018 based on ZH-1 satellite.
Monday, 14 December 2020
Poster
Zhenxia Zhang, Institute of Crustal Dynamics, CEA, Beijing, China, Xinqiao Li, Institute of High Energy Physics, Chinese academy sciences, Beijing, China, Si Liu, Changsha University of Science and Technology, Changsha, China, Ying Xiong, Peking University, School of Earth and Space Sciences, Beijing, China and Wang Yongfu, Peking University, School of Space Science, Beijing, China
Abstract:
Based on data from the Van Allen Probes and ZH-1 satellites, relativistic electron enhancements in extremely low L-shell Regions (reaching L~3) were observed during major geomagnetic storm (minimum Dst`-190 nT). Contrary to what occurs in the outer belt, such an intense and deep electron penetration event is rare and more interesting. Strong whistler-mode (chorus and hiss) waves, with amplitudes 81-126 pT, were also observed in the extremely low L-shell simultaneously (reaching L~2.5) where the plasmapause was suppressed. The bounce-averaged diffusion coefficient calculations support that the chorus waves can play a significantly important role in diffusing and accelerating the 1-3 MeV electrons even in such low L-shells during storms. This is the first time that the electron acceleration induced by chorus waves in the extremely low L-shell region is reported. This new finding will help to deeply understand the electron acceleration process in radiation belt physics.
A robust evidence is demonstrated clearly that the energetic electrons with energy 30 keV∼0.6 MeV are injected into the inner belt near equator and SAA region in dayside during the main phase of storm, thereafter induce the flux enhancement of electrons by 2∼3 times. While there are not enhancement for the electrons above 0.6 MeV. This is the first time that we have reported the upper limit of energy (near 0.6 MeV) for electron filling in the inner radiation belt and SAA region during this major storm thanks to the good energy resolution and wide detection range. Proton loss in outer boundary of inner radiation belt takes place in energy of 2∼220 MeV extensively during the occurrence of this storm but the loss mechanism is energy dependence which is consistent with some previous studies. It is confirmed that the magnetic field line curvature scattering plays a significantly role in the proton loss phenomenon in energy 30−100 MeV during this storm. This work provides a beneficial help to comprehensively understand the charged particles trapping and loss in SAA region and inner radiation belt dynamic physics.
