磁云边界层内朗缪尔波活动现象的初步研究  

Study on Langmuir Wave Activities Within the Magnetic Cloud Boundary Layers

作　　者：左平兵[1,2] 朱春明[1,2] 魏奉思[1] 冯学尚[1] 李汇军[1,2] 

机构地区：[1]中国科学院空间科学与应用研究中心空间天气学国家重点实验室,北京100190 [2]中国科学院研究生院

出　　处：《空间科学学报》2009年第3期262-267,共6页Chinese Journal of Space Science

基　　金：国家自然科学基金项目(40536029,40621003,40674084,40574068,40804046);973计划(2006CB806304)共同资助

摘　　要：对35例磁云边界层内朗缪尔波活动现象进行了初步分析，发现两类磁云边界层内特有的朗缪尔波活动现象．一类足相对于邻近鞘区和磁云本体，整个边界层内朗缪尔波活动增强；另一类是短时间的朗缪尔波爆发现象，同时伴随着宽频带的多普勒频移离子声波活动．考察了其中一例朗缪尔波爆发事件对应的高分辨率电子分布函数数据，发现速度约为7×10^3km／s的电子束流形成尾峰分布不稳定性导致了朗缪尔波的爆发．Two particular types of Langmuir wave activities are found within the Magnetic Cloud Boundary Layers （MCBL）： Langmuir wave enhancements in entire region of MCBL compared with the adjacent magnetic cloud body and sheath region for majority MCBL and the rapid Langmuir wave burst phenomena associated with broad-band Doppler shifted ion-acoustic wave activities for a few MCBL. On 3 Oct., 2000, WIND detected a typical MCBL inside which rapid Langmuir waves burst was observed. The Langmuir waves burst was right corresponded to the magnetic field minimum within the MCBL. The analysis based on high resolution electron distribution function data indicates that the bump-on-tail instability, resulting from the electron beam with beam velocity Vb about 7 × 10^3 km/s, is responsible for the rapid Langmuir waves burst.

关 键 词：磁云边界层 朗缪尔波 电子束流 

分 类 号：P353[天文地球—空间物理学]