WIND observations of plasma waves inside the magnetic cloud boundary layers  

作　　者：WEI Fengsi ZHONG Dingkun FENG Xueshang YANG Fang LIU Rui 

机构地区：[1]SIGMA Weather Group, Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100080, China [2]Graduate School, Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Chinese Science Bulletin》2005年第18期2051-2056,共6页

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.G200078405,40336053,40274052).

摘　　要：Based on the WIND observational data for the plasma waves from thermal noise receptor (TNR) working on the frequency 4―256 kHz and the solar wind and the magnetic fields, we analyze the plasma wave activities in the 60 magnetic cloud’s boundary layers (BLs) and find that there are often various plasma wave activities in the BLs, which are different from those in the adjacent solar wind (SW) and the magnetic clouds (MC). The basic characteris-tics are that: (1) the enhancement of the Langmuir wave near the electronic plasma frequency (fpe) is a dominant wave ac-tivity, which occupies 75% investigated samples; (2) the events enhanced both in the langmuir and ion acustic (f < fpe) waves are about 60% of investigated samples; (3) broadband, continuous enhancement events in the plasma wave activities were observed in the whole frequency band of TNR, and about 30% of the 60 samples, however, were not observed in the SW and the MC investigated events; (4) although the ratio of the temperatures between the electon and proton, Te/Tp≤1, the ion caustic wave enhancement activities are still often observed in the BLs, which makes it difficult to ex- plain them by the traditional plasma theory. New results reported in this paper further show that the magnetic cloud’s BL is an important dynamic structure, which could provide useful diagnosis for understanding the cloud’s BL physics and could expand a space developing space plasma wave theory.Based on the WIND observational data for the plasma waves from thermal noise receptor （TNR） working on the frequency 4-256 kHz and the solar wind and the magnetic fields, we analyze the plasma wave activities in the 60 magnetic cloud＇s boundary layers （BLs） and find that there are often various plasma wave activities in the BLs, which are different from those in the adjacent solar wind （SW） and the magnetic clouds （MC）. The basic characteristics are that： （1） the enhancement of the Langmuir wave near the electronic plasma frequency （fpe） is a dominant wave activity, which occupies 75% investigated samples; （2） the events enhanced both in the langmuir and ion acustic （f〈fpe） waves are about 60% of investigated samples; （3） broadband, continuous enhancement events in the plasma wave activities were observed in the whole frequency band of TNR, and about 30% of the 60 samples, however, were not observed in the SW and the MC investigated events; （4） although the ratio of the temperatures between the electon and proton, Te/Tp ≤1, the ion caustic wave enhancement activities are still often observed in the BLs, which makes it difficult to explain them by the traditional plasma theory. New results reported in this paper further show that the magnetic cloud＇s BL is an important dynamic structure, which could provide useful diagnosis for understanding the cloud＇s BL physics and could expand a space developing space plasma wave theory.

关 键 词：边界层 等离子体波 磁场 Langmuir波 频率分布 

分 类 号：P353.8[天文地球—空间物理学]