电离层上行O^+离子沿不同经度处的磁力线向磁层的传输

TRANSPORT OF IONOSPHERIC UP-FLOWING O^+ ION ALONG THE FIELD LINE AT VARIOUS LONGITUDE TO THE MAGNETOSPHERE

根据解析求解引导中心近似的动力学方程得到的离子分布函数 ,研究了不同Kp指数条件下起源于不同电离层区域的上行O+离子通量密度沿不同经度处的磁力线的定态分布 ,并研究了上行O+离子向不同磁层区域传输的特性 .主要结果为 :( 1 )起源于向阳面极光带外侧及更低纬区的电离层离子基本上传输到向阳面磁层区 ;起源于背阳面极光带及更低纬区的电离层离子基本上传输到背阳面磁尾等离子体片区和闭合磁力线区 ;起源于极盖区及向阳面极光带内侧的电离层离子基本上传输到等离子体幔区和磁瓣区 .( 2 )上行离子主要分布在近地空间 ,其通量密度相对于地心距离呈负梯度 .( 3)地磁活动指数Kp 增高时上行离子进入磁层的概率增大 ,因而上行离子起动力学作用的地球空间范围增大 .所得结果可解释有关地顶的观测特征 。

According to ion's distribution function found from the dynamic equation, static flux distribution of up flowing O + ion originating from various ionospheric region along the field line at various longitude and the ion transport feature are studied. The results show that: (1) The ion originating from equator side of the dayside auroral zone and lower latitude region mainly transports into dayside magnetospheric region. The ion originating from the polar cap and the polarside of the dayside auroral zone mainly transports into the magneto mantle and lob. The ion originating from the nightside auroral zone and lower latitude region mainly transports into the plasmasheet and closed field line region in the magnetotail. (2) The ionospheric up flowing ion mainly distributes in the near geo space and its flux has a negative gradient versus geo center distance. (3) If K p is higher the probability of the up flowing ions to entry the magnetosphere will be bigger and region where the up flowing ions are dominant will be bigger. The theoretic results can interpret some features of the geopause and the theoretic flux of the ion in the magnetotail is consistent with the observation.