空间科学学报2018，Vol.38Issue(2)：169-177,9.DOI:10.11728/cjss2018.02.169
通量传输事件相关的动力学磁场湍流观测研究
Kinetic Magnetic Turbulence Associated with Flux Transfer Events Observed by THEMIS Satellite
摘要
Abstract
Intense magnetic fluctuations are recorded in the magnetosphere near the magnetopause when Flux Transfer Events (FTE) are passed by the THEMIS satellites.The power spectra of these fluctuations obtained by Fast Fourier Transform (FFT) show that the Power Spectra Density (PSD) peaks around the disturbance frequency of FTE (about 0.1Hz),and decreases from the proton gyrofrequency (about 1 Hz) to 64 Hz following a power law of P0f-α These fluctuations are interpreted as magnetic turbulences in the kinetic regime in the Low Latitude Boundary Layer (LLBL).The results show that both the PSD and the slopes of the power spectra α decrease when the observing satellite position is more and more away from the magnetopause or the FTE location in the LLBL.However,α and the PSD are independent from the azimuthal position of FTE or local time of the low latitude magnetopause.All these observations suggest that the moving FTEs are the source for these magnetic fluctuations.Large scale perturbations on the magnetopause,e.g.FTEs and the associated magnetic turbulences,provide a hint which may reveal the interaction between the magnetosheath and the magnetosphere in a kinetic scale.Whether the magnetic turbulences can provide enough viscosity for the forming of the flow vortices on the magnetospheric side of FTEs or not need to be further confirmed.关键词
通量传输事件/磁场湍流/幂律指数/功率谱密度/黏滞性Key words
Flux transfer event/Magnetic turbulence/Spectral index/Power spectra density/Viscosity分类
天文与地球科学引用本文复制引用
周招弟,张辉,倪彬彬,张晓佳,朱昌波,付松..通量传输事件相关的动力学磁场湍流观测研究[J].空间科学学报,2018,38(2):169-177,9.基金项目
国家自然科学基金项目(41274171)和中国科学院科技创新交叉与合作团队项目(KZZD-EW-01-3)共同资助 （41274171）
