行星际磁场By对弓激波影响的MHD结果  

Effects of IMF By on the bow shock:MHD results

作　　者：王明 于超 吕建永[1] 袁换只 周悦 刘子谦 虞超 顾春丽 WANG Ming;YU Chao;LU JianYong;YUAN HuanZhi;ZHOU Yue;LIU ZiQian;YU Chao;GU ChunLi(Institute of Space Weather,School of Math&Statistics,Nanjing University of Information Science&Technology,Nanjing 210044,China;Key Laboratory of Space Weather,National Center for Space Weather,China Meteorological Administration,Beijing 100081,China;Center for Space Science and Applied Research,Chinese Academy of Sciences,Beijing 100080,China;Yangzhong Meteorological Bureau,Yangzhong Jiangsu 212200,China;Beijing Institute of Applied Meteorology,Beijing 100029,China)

机构地区：[1]南京信息工程大学数学与统计学院空间天气研究所,南京210044 [2]中国气象局空间天气重点开放实验室/国家空间天气监测预警中心,北京100081 [3]中国科学院国家空间科学中心,北京100080 [4]江苏省扬中市气象局,江苏扬中212200 [5]北京应用气象研究所,北京100029

出　　处：《地球物理学报》2020年第5期1725-1737,共13页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41604141,41574158,U1631107);江苏省自然科学基金(BK20160952);国家卫星气象中心重点开放实验室开放研究基金;江苏省双创团队资助.

摘　　要：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.Using the global magnetohydrodynamic(MHD)simulation,we investigate the effects of the Y component of interplanetary magnetic field(IMF)By on the shape and size of the bow shock.Our results show that with the increasing absolute value of By,the bow shock′s standoff distance,the flaring angle of the rotationally symmetry,the north-south asymmetric parameter,and the rotationally asymmetric parameter all increase.The extent of the By effects on the bow shock′s standoff distance can reach 5 R E.The influences of the eastward and westward By on the bow shock are symmetric.For the same absolute value of the eastward and westward By,the bow shock′s standoff distances,the flaring angles of the rotationally symmetry,and the rotationally asymmetric parameters have the same values,while the north-south asymmetric parameters have the same absolute values but with a different sign.The bow shock tail′s cross-section is elongated in the north-south direction under By conditions,and the extent of the elongation is enhanced with increasing By.The elongation of the bow shock tail′s cross-section is closely related to the magnetosonic Mach number.

关 键 词：行星际磁场By 弓激波 磁流体模拟 

分 类 号：P352[天文地球—空间物理学]