Exohiss wave enhancement following substorm electron injection in the dayside magnetosphere  

作　　者：ZhongLei Gao ZhenPeng Su FuLiang Xiao HuiNan Zheng YuMing Wang Shui Wang H. E. Spence G.D. Reeves D. N. Baker J. B. Blake H.O. Funsten 

机构地区：[1]School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410004, China [2]CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei,Anhui 230026, China [3]Collaborative Innovation Center of Astronautical Science and Technology, University of Science and Technology of China, Hefei 230026, China [4]Mengcheng National Geophysical Observatory, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China [5]Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire, USA [6]Space Science and Applications Group, Los Alamos National Laboratory, Los Alamos, New Mexico, USA [7]Space Sciences Division, New Mexico Consortium, Los Alamos, New Mexico, USA [8]Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Colorado, USA [9]The Aerospace Corporation, Los Angeles, California, USA [10]ISR Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA

出　　处：《Earth and Planetary Physics》2018年第5期359-370,共12页地球与行星物理（英文版）

基　　金：supported by National Natural Science Foundation of China grants 41631071, 41774170, 41274174, 41174125, 41131065, 41421063, 41231066 and 41304134;Chinese Academy of Sciences grants KZCX2-EW-QN510 and KZZD-EW-01-4;CAS Key Research Program of Frontier Sciences grant QYZDB-SSWDQC015;National Key Basic Research Special Foundation of China Grant No. 2011CB811403;Fundamental Research Funds for the Central Universities WK2080000077

摘　　要：Exohiss is a low-frequency structureless whistler-mode emission potentially contributing to the precipitation loss of radiation belt electrons outside the plasmasphere. Exohiss is usually considered the plasmaspheric hiss leaked out of the dayside plasmapause.However, the evolution of exohiss after the leakage has not been fully understood. Here we report the prompt enhancements of exohiss waves following substorm injections observed by Van Allen Probes. Within several minutes, the energetic electron fluxes around 100 keV were enhanced by up to 5 times, accompanied by an up to 10-time increase of the exohiss wave power. These substorm-injected electrons are shown to produce a new peak of linear growth rate in the exohiss band(< 0.1 f_(ce)). The corresponding path-integrated growth rate of wave power within 10° latitude of the magnetic equatorial plane can reach 13.4, approximately explaining the observed enhancement of exohiss waves. These observations and simulations suggest that the substorm-injected energetic electrons could amplify the preexisting exohiss waves.Exohiss is a low-frequency structureless whistler-mode emission potentially contributing to the precipitation loss of radiation belt electrons outside the plasmasphere. Exohiss is usually considered the plasmaspheric hiss leaked out of the dayside plasmapause. However, the evolution of exohiss after the leakage has not been fully understood. Here we report the prompt enhancements of exohiss waves following substorm injections observed byVan Allen Probes. Within several minutes, the energetic electron fluxes around 100 keV were enhanced by up to 5 times, accompanied by an up to 10-time increase of the exohiss wave power. These substorm-injected electrons are shown to produce a new peak of linear growth rate in the exohiss band （〈 0.1fce）. The corresponding path-integrated growth rate of wave power within 10° latitude of the magnetic equatorial plane can reach 13.4, approximately explaining the observed enhancement of exohiss waves. These observations and simulations suggest that the substorm-injected energetic electrons could amplify the preexisting exohiss waves.

关 键 词：exohiss substorm injection radiation belt whistler-mode instability 

分 类 号：P35[天文地球—空间物理学]