SM034-0013
Simultaneous Observations of Electromagnetic Ion Cyclotron Waves and Magnetosonic Waves

Monday, 14 December 2020
Poster
Shangchun Teng1, Qianli Ma2, Xin Tao3, Yifan Wu3 and Wen Li4, (1)University of Science and Technology of China, Earth and Planetary Sciences, Hefei, China, (2)UCLA, Department of Atmospheric and Oceanic Sciences, Los Angeles, CA, United States, (3)University of Science and Technology of China, Hefei, China, (4)Boston University, Boston, MA, United States
Abstract:
Magnetosonic (MS) waves and electromagnetic ion cyclotron (EMIC) waves are two important plasma wave modes in the magnetosphere. Most previous studies investigated these two waves separately; however, some recent works suggest that they could be closely related. Using more than 5 years of Van Allen Probes data, we constructed the global distribution of simultaneous observations of these two waves for the first time. We find a total of 237 events, most of which are present from dayside to duskside. Furthermore, from a detailed case study based on linear growth rate calculations, we provide the first observational evidence for a previous theoretical prediction that anisotropic ring-like proton distributions could excite MS and EMIC waves simultaneously. Our new results are crucial to understand the generation mechanisms and relation of MS and EMIC waves and to evaluate their combined effects on energetic electron and ion dynamics.
<< Previous Abstract | Next Abstract >>