Determination of the Kelvin-Helmholtz Wave Parameters on the Magnetopause in Single-spacecraft Observations  

作　　者：LIN Dong WANG Chi LI Wenya TANG Binbin 

机构地区：[1]State Key Laboratory of Space Weather,Center for Space Science and Applied Research,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences

出　　处：《空间科学学报》2015年第4期403-408,共6页Chinese Journal of Space Science

基　　金：Supported by the National Basic Research Program(2012CB825602);National Natural Science Foundation of China(41231067,41174143);the Specialized Research Fund for State Key Laboratories of China

摘　　要：Kelvin-Helmholtz(K-H) waves are formed from the triggering of the K-H instability on the magnetopause,which is a candidate mechanism for solar wind entry into the magnetosphere,especially under northward interplanetary magnetic field conditions.In this study,a K-H wave event was identified from the observation of probe B of the Time History of Events and Macroscale Interactions during Substorms(THEMIS) mission on 15 May 2008.A new method to determine the wave parameters of the K-H waves in single-spacecraft observations is proposed.The dominant wave period is determined by three kinds of spectrograms for three key parameters,namely the ion density,the ion temperature,and the z component of magnetic field.The phase velocity is estimated by calculating the center-of-mass velocity of the detected K-H vortex region.This approximation is validated by comparison with other alternative methods.The method to determine the wave parameters is a first step to further study K-H wave properties and their relationship with interplanetary conditions.Kelvin-Helmholtz(K-H) waves are formed from the triggering of the K-H instability on the magnetopause,which is a candidate mechanism for solar wind entry into the magnetosphere,especially under northward interplanetary magnetic field conditions.In this study,a K-H wave event was identified from the observation of probe B of the Time History of Events and Macroscale Interactions during Substorms(THEMIS) mission on 15 May 2008.A new method to determine the wave parameters of the K-H waves in single-spacecraft observations is proposed.The dominant wave period is determined by three kinds of spectrograms for three key parameters,namely the ion density,the ion temperature,and the z component of magnetic field.The phase velocity is estimated by calculating the center-of-mass velocity of the detected K-H vortex region.This approximation is validated by comparison with other alternative methods.The method to determine the wave parameters is a first step to further study K-H wave properties and their relationship with interplanetary conditions.

关 键 词：KELVIN-HELMHOLTZ WAVES MAGNETOPAUSE Single-spacecr 

分 类 号：P353[天文地球—空间物理学]