1998年5月2日日冕亮度观测图的数值研究

采用数值手段模拟了1998年5月2日日冕亮度观测图.计算模式改进为球坐标系下特殊的二维理想磁流体(MHD)模型,即把(γ,φ)坐标建立在SOHO观测日冕亮度的子午面上,消除了子午面极区的几何奇异性.根据SOHO日冕观测布置磁极子得到初始磁场位形,内边界条件采用自洽的投影特征线边界条件,计算迭代出稳态的多冕流磁场结构,得到了与观测基本一致的亮度图.计算结果表明在太阳表面附近磁场位形对太阳风等离子参数分布起控制作用.

NUMERICAL RESEARCH ABOUT WHITE LIGHT CORONAGRAPH FIGURE OBSERVED AT MAY 2 1998

A new model of 2-D ideal magnetohydrodynamic equations, which sets spherical coordinates （γ, φ） on the plane of sky to avoid singular geometry at solar poles, is employed to simulate white light coronagraph figure. Numerical white light figure of the final self-consistent steady state, calculated with initial magnetic field constructed from a magnetic hexapole and several dipoles and with projected characteristic inner boundary condition, agrees basically with the observed coronagraph figure. The simulation also shows that magnetic structure dominates the solar wind flow field.