title: Determining the mechanism of cusp proton aurora.
abstract: Earth's cusp proton aurora occurs near the prenoon and is primarily produced by the precipitation of solar energetic (2-10 keV) protons. Cusp auroral precipitation provides a direct source of energy for the high-latitude dayside upper atmosphere, contributing to chemical composition change and global climate variability. Previous studies have indicated that magnetic reconnection allows solar energetic protons to cross the magnetopause and enter the cusp region, producing cusp auroral precipitation. However, energetic protons are easily trapped in the cusp region due to a minimum magnetic field existing there. Hence, the mechanism of cusp proton aurora has remained a significant challenge for tens of years. Based on the satellite data and calculations of diffusion equation, we demonstrate that EMIC waves can yield the trapped proton scattering that causes cusp proton aurora. This moves forward a step toward identifying the generation mechanism of cusp proton aurora.
authors.affiliation: School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410004, China. flxiao@126.com
authors.forename: Fuliang
authors.initials: F
authors.lastname: Xiao
authors.forename: Qiugang
authors.initials: Q
authors.lastname: Zong
authors.forename: Zhenpeng
authors.initials: Z
authors.lastname: Su
authors.forename: Chang
authors.initials: C
authors.lastname: Yang
authors.forename: Zhaoguo
authors.initials: Z
authors.lastname: He
authors.forename: Yongfu
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhonglei
authors.initials: Z
authors.lastname: Gao
mesh_terms: D001272:Atmosphere / Q000032:analysis* / Q000737:chemistry*; D003198:Computer Simulation; D004735:Energy Transfer; D008962:Models, Theoretical; D011522:Protons; D012993:Solar Energy
chemical_list: D011522:Protons