哨声模波对高能电子槽区和外辐射带的调节作用  

Whistler-mode waves modify the high-energy electron slot region and the outer radiation belt

作　　者：李柳元[1] 曹晋滨[1] 周国成[1] 

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,北京100080

出　　处：《地球物理学报》2008年第2期316-324,共9页Chinese Journal of Geophysics

基　　金：国家自然科学基金(40604018;40523006);973项目(2006CB80630);中国科学院空间科学与应用研究中心项目(O72114AA4S);中国科学院项目(O692133A29S)资助

摘　　要：本文利用磁层哨声模嘶声和合声波的幅度分布模型、近赤道背景电子(能量在eV量级)的数密度分布模型和IGRF10磁场模型建立了一个高能电子(能量大于50keV)准线性扩散模型.模型的数值结果表明,在不同的地磁条件下,等离子体层顶位置的变化改变了磁层背景电子数密度的空间分布,从而改变了哨声模嘶声对高能电子有效的投掷角扩散(损失)区域,同时也改变了哨声模合声波对高能电子有效的动量扩散(加速)区域.哨声模嘶声对电子投掷角扩散区域的变化和CRRES卫星探测到的高能电子的槽区变化是一致的,而合声波对电子的动量扩散区域的变化和卫星探测到外辐射带的变化相同.这种对应关系说明:在不同的地磁条件下,哨声模波对高能电子扩散区域的变化是造成高能电子槽区和外辐射带的空间位置和大小变化的一个重要因素.在一些强磁暴期间,由于嘶声对部分能量范围电子的投掷角扩散作用消失,这些电子的槽区也随之消失,从而使内外辐射带连接在一起.A global quasi-linear diffusion model of electrons is established by using the whistler-mode wave amplitude distribution model, the electron density distribution model and the IGRF10 magnetic field model in 1 〈 L 〈 7 region. The numerical results reveal that the variation of plasmapause location changes the electron loss region controlled by whistler-mode hiss and acceleration region controlled by whistler-mode chorus through changing electron density and wave intensity under different geomagnetic conditions. The variation of the electron loss region is consistent with the variation of the slot region, and meanwhile the variation of the electron acceleration region is consistent with the variation of the outer radiation belt, suggesting that variations of electron diffusion regions by whistler-mode waves cause the structure-variations （including size and spatial location） of the slot region and the outer radiation belt. During the recovery phase of a great storm, for electrons with certain energy, as their loss region controlled by hiss disappears, the inner radiation belt may connect with the outer radiation belt together completely.

关 键 词：哨声模嘶声 合声 高能电子 槽区 外辐射带 

分 类 号：P353[天文地球—空间物理学]