磁壳参数L与磁暴Dst指数和行星际条件的关系

用磁坐标L-/A来描述地球近地空间粒子特性和卫星位置是近年来空间物理探测研究和数据分析中的一个新趋势.利用T96磁场模型计算了L值,并比较了在地球磁层剧烈活动期间和不同行星际条件下,用偶极子模型,国际参照磁场(IGRF)模型,和T96磁场模型这三种方式计算得到的地球表面L-A磁坐标之间的区别.在地磁纬度大于30°时偶极子近似和IGRF磁场模型计算得到的L值差别开始增大.在地磁纬度大于50°时,用IGRF磁场模型和T96磁场模型计算得到的L值差别开始增大.由于T96磁场模型引入了行星际磁场南北和东西分量,计算的L值包含了行星际条件的影响,并具有了随地方时变化的特性.本工作对于辐射带粒子动态模式的建立,以及正确理解卫星磁坐标位置等具有重要意义.

RELATION BETWEEN MAGNETIC SHELL PARAMETER L, Dst AND IMF

It is a new trend to use the magnetic coordinate L-A. to describe space particle features and position of spacecraft. T96 model is used to calculate magnetic shell parameter, and the difference between L values calculated from Dipolar model, IGRF and T96 were compared. The difference between L values calculated from Dipolar model and IGRF, begin to increase when magnetic latitude is larger than 30? Also,the difference between L values calculated from IGRF and T96, begin to increase when magnetic latitude is larger than 50? The L values are therefore dependent on the IMF (interplanetary magnetic field) and have also the dependence of local time. This work is meaningful to radiation belt dynamic modeling and understanding of magnetic position of satellite.