子午面太阳风的大尺度结构研究

Three-dimensional (3D) heliospheric background at solar minimum was investigated by using 3D magnetohydrodynamic (MHD) simulation. The initial and boundary conditions was defined according to the observations of the photospheric magnetic field and coronal polarized brightness in the simulation. The simulation result was roughly consistent with the observation of Ulysses during its first travel across both solar poles. This project also studied the sun-earth connected event in January 1997 by using the numerical scheme developed above. In addition, Lu jiangyong, the principal investigator of this project, collaborated with Professor Zank in Bartol Research Institute, University of Delaware, Newark, USA, and used kinetic model to examined the transportation of energetic particles in the background of radial magnetic field, such as high heliographic latitude heliosphere. The results demonstrated that the presence of adiabatic focusing resulted in highly asymmetric particle propagation in opposite directions with typically more particles in the sunward hemisphere than in the antisunward hemisphere and the distribution within each hemisphere was quasiisotropic. This result can explain the highly anisotropic velocity distribution of interstellar pickup ions observed recently at high latitudes from SWICS on Ulysses.

Ulysses飞船是至今为止第一个飞越太阳两极考察日球太阳风三维结构的飞船。其观测结果墙?0年来有关的理论所不能解释的。本申请即是根据Ulysses飞船的有关观测资料，建立子午面内太阳风的新模型，分析对比现有功能的作用，发展高速流加速机制。该项目的实施，对了解太阳风的动力学过程和定量了解行星际扰动传播都有重要科学意义和潜在应用价值。