Dependence of magnetic field just inside the magnetopause on subsolar standoff distance:Global MHD results  

作　　者：WANG Ming LU JianYong LIU ZiQian PEI ShiXin 

机构地区：[1]College of Math ＆ Physics, Nanjing University of Information Science ＆ Technology, Nanjing 210044, China [2]National Center for Space Weather, China Meteorology Administration, Beijing 100081, China [3]Chinese Academy of Meteorological Sciences, Beijing 100081, China [4]Graduate University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Chinese Science Bulletin》2012年第12期1438-1442,共5页

基　　金：supported by the National Natural Science Foundation of China(40874087 and 41031063);the China Meteorology Administration(GYHY201106011);the China Public Science and Technology Research Funds Projects of Ocean(201005017)

摘　　要：The subsolar magnetopause is the boundary between the solar wind and the Earth's magnetosphere,where reduced solar wind dynamic pressure is equal to the magnetic pressure of the Earth's outer magnetosphere.We use a global magnetohydrodynamic (MHD)model to estimate the ratio f of the compressed magnetic field just inside the subsolar magnetopause to the purely dipolar magnetic field.We also compare our numerical results to a similar work by Shue,which used Time History of Events and Macroscale Interactions during Substorms(THEMIS)data.Our results show that the ratio f is linearly proportional to the subsolar magnetopause standoff distance(r0)for both the northward and southward interplanetary magnetic field,properties consistent with Shue but with a smaller proportionality constant.However,previous theoretical studies show that f is nearly independent of the subsolar standoff distance.The global model results also show that f is smaller for the southward Interplanetary Magnetic Field(IMF)under the same r0,and that the proportionality constant for the southward IMF is larger than that for the northward IMF.Both conclusions agree with statistical results from observations by Shue.The subsolar magnetopause is the boundary between the solar wind and the Earth＇s magnetosphere, where reduced solar wind dynamic pressure is equal to the magnetic pressure of the Earth＇s outer magnetosphere. We use a global magnetohydrodynamic （MHD） model to estimate the ratiofof the compressed magnetic field just inside the subsolar magnetopause to the purely dipolar magnetic field. We also compare our numerical results to a similar work by Shue, which used Time History of Events and Mac- roseale Interactions during Substorms （THEMIS） data. Our results show that the ratio f is linearly proportional to the subsolar magnetopanse standoff distance （r0） for both the northward and southward interplanetary magnetic field, properties consistent with Shue but with a smaller proportionality constant. However, previous theoretical studies show thatfis nearly independent of the subsolar standoff distance. The global model results also show that f is smaller for the southward Interplanetary Magnetic Field （IMF） under the same r0, and that the proportionality constant for the southward IMF is larger than that for the northward IMF. Both conclusions agree with statistical results from observations by Shue.

关 键 词：行星际磁场 地球磁层 磁流体 距离 国际货币基金组织 模型估计 相互作用 历史事件 

分 类 号：P353[天文地球—空间物理学] P3[天文地球—地球物理学]