WSA太阳风经验模型及其应用  

Analysis of Present Research on the WSA Solar Wind Model

作　　者：杨子才 沈芳 杨易 冯学尚 YANG Zicai;SHEN Fang;YANG Yi;FENG Xueshang(National Space Science Center, Chinese Academy of Sciences, Beijing 100190;University of Chinese Academy of Sciences, Beijing 100049;Institute of Space Science and Applied Technology, Harbin Institute of Technolgy, Shenzhen 518055)

机构地区：[1]中国科学院国家空间科学中心,北京100190 [2]中国科学院大学,北京100049 [3]哈尔滨工业大学(深圳)空间科学与应用技术研究院,深圳518055

出　　处：《空间科学学报》2018年第3期285-295,共11页Chinese Journal of Space Science

基　　金：国家自然科学基金项目(41231068;41474152;41531073;41774184);国家重点实验室专项研究基金;国家"万人计划"青年拔尖人才项目共同资助

摘　　要：Wang-Sheely-Arge(WSA)模型是对准稳态太阳风的经验和物理相结合的描述,其利用观测的日面磁图作为输入,可以提前3到4天预测L1点处的太阳风速度和行星际磁场极性.WSA模型是在WS模型的基础上经过若干改进形成的实时预报模式,之后又借鉴Distance from the Coronal Hole Boundary(DCHB)模型的参数,进一步改进了太阳风速度关系式,形成了目前常见的形式.WSA经验模型由日冕磁场模型、太阳风速度关系式和一维运动学模型三部分组成.在实际应用过程中,基本步骤包括观测磁图预处理、日冕三维磁场反演、计算日冕磁场参数、计算太阳风的速度分布和将太阳风映射到1AU等环节.在发展过程中,WSA模型经历了一些细节上的调整变化,例如观测磁图数据的来源、日冕磁场模型的类型、经验速度关系中自由系数的取值等.许多研究对如何改善模型的预报效果进行了探索.The Wang-Sheeley-Arge（WSA） model is an empirical model that can predict the background solar wind speed and Interplanetary Magnetic Field（IMF）polarity on the Earth It utilizes the line-of-sight synoptic solar magnetograms as input to give predictions about 3 to 4 days in advance. It is an improved version of the original Wang and Sheeley（WS） model. The relationship was generalized according to the parameters of the Coronal Hole Boundary（DCHB） model. The solar wind velocity is first determined at a certain height by the expansion factor of the magnetic field and the minimum angular distance that an open field footpoint lies from nearest coronal hole boundary. And then a simple 1-D modified kinematic model（1-DMK）, which includes an ad hoc method to account for stream interactions, is used to transport the wind from the corona out to the Earth. In the course of development, the WSA model has been improved gradually in the details,such as the source of synoptic magnetograms, the type of coronal magnetic field model, the values of free parameters in velocity relation, the way of mapping the solar wind to earth and so on. Many studies were devoted to improve the prediction accuracy of the WSA model, and it is widely used now in many Magnetohydrodynamic（MHD） solar wind model.

关 键 词：WSA模型 太阳风 日冕磁场 

分 类 号：P353[天文地球—空间物理学]