利用全球磁流体模拟的结果,本文研究了行星际磁场By对弓激波位型的影响.结果显示:随着行星际磁场By绝对值的增大,弓激波的日下点距离、旋转对称张角、南北非对称性以及旋转非对称性均随之增加.其中,By对弓激波日下点距离的影响可达5 R ...利用全球磁流体模拟的结果,本文研究了行星际磁场By对弓激波位型的影响.结果显示:随着行星际磁场By绝对值的增大,弓激波的日下点距离、旋转对称张角、南北非对称性以及旋转非对称性均随之增加.其中,By对弓激波日下点距离的影响可达5 R E左右.东向By和西向By对弓激波位型影响具有对称性,东向By和西向By大小相同时弓激波日下点距离、旋转对称张角以及旋转非对称性参数均相同,而南北非对称性参数大小相同正负相反.行星际磁场By占主导时弓激波尾部横截面在南北方向上拉伸,并且拉伸程度随着By绝对值的增大而增大,弓激波尾部横截面的拉伸现象与磁声波马赫数密切相关.展开更多
The dipole tilt angle has beenfound to affect Earth's bow shock.This work presents a quantitative relationship between the dipole tilt angle and the bow shock location and flaring angle.We collected a large data s...The dipole tilt angle has beenfound to affect Earth's bow shock.This work presents a quantitative relationship between the dipole tilt angle and the bow shock location and flaring angle.We collected a large data set of bow shock crossings from four different satellites(IMP 8,Geotail,Magion 4,and Cluster),including some recent crossings obtained during 2012-2013.The results from a statistical analysis demonstrate that:(1)the subsolar standoff distance increases but the flaring angle decreases with increasing dipole tilt angle;(2)when the dipole tilt angle changes sign from negative to positive,the dayside bow shock moves toward Earth and the shift can be as much as 2.29 R_E,during which the flaring angle increases;and(3)the shape of bow shock in the northern and southern hemispheres differs.For the northern hemisphere bow shock,with increasing positive/negative dipole tilt angle,the flaring angle increases/decreases.While for the southern hemisphere,the trend is the opposite;with increasing positive/negative dipole tilt angle,the flaring angle decreases/increases.These results are helpful for future bow shock modeling that needs to include the effects of dipole tilt angle.展开更多
文摘利用全球磁流体模拟的结果,本文研究了行星际磁场By对弓激波位型的影响.结果显示:随着行星际磁场By绝对值的增大,弓激波的日下点距离、旋转对称张角、南北非对称性以及旋转非对称性均随之增加.其中,By对弓激波日下点距离的影响可达5 R E左右.东向By和西向By对弓激波位型影响具有对称性,东向By和西向By大小相同时弓激波日下点距离、旋转对称张角以及旋转非对称性参数均相同,而南北非对称性参数大小相同正负相反.行星际磁场By占主导时弓激波尾部横截面在南北方向上拉伸,并且拉伸程度随着By绝对值的增大而增大,弓激波尾部横截面的拉伸现象与磁声波马赫数密切相关.
基金supported by the National Basic Research Program of China (Grant No.2012CB825606)the National Natural Science Foundation of China(Grant Nos.41574158,U1631107)the China Meteorological Administration(Grant No.GYHY201106011)
文摘The dipole tilt angle has beenfound to affect Earth's bow shock.This work presents a quantitative relationship between the dipole tilt angle and the bow shock location and flaring angle.We collected a large data set of bow shock crossings from four different satellites(IMP 8,Geotail,Magion 4,and Cluster),including some recent crossings obtained during 2012-2013.The results from a statistical analysis demonstrate that:(1)the subsolar standoff distance increases but the flaring angle decreases with increasing dipole tilt angle;(2)when the dipole tilt angle changes sign from negative to positive,the dayside bow shock moves toward Earth and the shift can be as much as 2.29 R_E,during which the flaring angle increases;and(3)the shape of bow shock in the northern and southern hemispheres differs.For the northern hemisphere bow shock,with increasing positive/negative dipole tilt angle,the flaring angle increases/decreases.While for the southern hemisphere,the trend is the opposite;with increasing positive/negative dipole tilt angle,the flaring angle decreases/increases.These results are helpful for future bow shock modeling that needs to include the effects of dipole tilt angle.
