文章基本信息

标题：Electrostatic quasi-monochromatic waves in the downstream region of the Earth’s bow shock based on Geotail observations
其他标题：Electrostatic quasi-monochromatic waves in the downstream region of the Earth’s bow shock based on Geotail observations
本地全文：下载
作者：Koichi Shin ; Hirotsugu Kojima ; Hiroshi Matsumoto 等
期刊名称：Earth, Planets and Space
电子版ISSN：1880-5981
出版年度：2007
卷号：59
期号：2
页码：107-112
DOI：10.1186/BF03352683
出版社：Springer Verlag
摘要：Geotail plasma wave observations show the existence of intense electrostatic quasi-monochromatic (EQM) waves in the downstream region of the Earth’s bow shock. They oscillate parallel to the ambient magnetic field and appear at frequencies between the electron plasma and ion plasma frequencies. Although these waves have been believed to be Doppler-shifted ion acoustic waves, the typical plasma parameters observed in the downstream region do not support the generation conditions for ion acoustic waves. In this paper, the existence of cold electron beam-like components accompanying EQM waves is considered based on waveform and statistical analyses. Linear dispersion analyses using realistic plasma parameters revealed that the cold electron beams cause destabilization of electron acoustic waves at frequencies consistent with those of observed EQM waves. The results of observations and linear analyses suggest that EQM waves are generated by the destabilization of the electron acoustic mode.
关键词：Electrostatic plasma wave ;electron acoustic mode ;downstream region of the bow shock