title: Generation of proton aurora by magnetosonic waves.
abstract: Earth's proton aurora occurs over a broad MLT region and is produced by the precipitation of low-energy (2-10 keV) plasmasheet protons. Proton precipitation can alter chemical compositions of the atmosphere, linking solar activity with global climate variability. Previous studies proposed that electromagnetic ion cyclotron waves can resonate with protons, producing proton scattering precipitation. A long-outstanding question still remains whether there is another mechanism responsible for the proton aurora. Here, by performing satellite data analysis and diffusion equation calculations, we show that fast magnetosonic waves can produce trapped proton scattering that yields proton aurora. This provides a new insight into the mechanism of proton aurora. Furthermore, a ray-tracing study demonstrates that magnetosonic wave propagates over a broad MLT region, consistent with the global distribution of proton aurora.
authors.affiliation: School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410004, China.
authors.forename: Fuliang
authors.initials: F
authors.lastname: Xiao
authors.affiliation: School of Earth and Space Sciences, Peking University, Beijing 100871, China.
authors.forename: Qiugang
authors.initials: Q
authors.lastname: Zong
authors.affiliation: School of Earth and Space Sciences, Peking University, Beijing 100871, China.
authors.forename: Yongfu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Zhaoguo
authors.initials: Z
authors.lastname: He
authors.affiliation: Chinese Academy of Sciences Key Laboratory for Basic Plasma Physics, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Zhenpeng
authors.initials: Z
authors.lastname: Su
authors.affiliation: School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410004, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Yang
authors.affiliation: School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410004, China.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Zhou