A three-dimensional asymmetric magnetopause model
A three-dimensional asymmetric magnetopause model
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DOI：
10.1029/2009ja014235
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发表时间：
2010-04
影响因子：
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通讯作者：
R. Lin;Xiaoye Zhang;Siqing Liu;Yongli Wang;J. Gong
中科院分区：
文献类型：
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作者：
R. Lin;Xiaoye Zhang;Siqing Liu;Yongli Wang;J. Gong
[1]发展了一个新的三维非对称磁层顶模式，该模式修正了GSM坐标，并用太阳风动力和磁压(Pd+Pm)、行星际磁场(IMF)Bz和偶极子倾角进行了参数化。根据GeoTail、IMP 8、Interball、Tc1、亚暴期间事件和大尺度相互作用时间史(THEMIS)、风、星团、极地、洛斯阿拉莫斯国家实验室(LANL)、GOES和Hawkeye的磁层顶交叉点，以及来自ACE、Wind或OMNI的相应上游太阳风参数，该模式是在划分的区域内用Lvenberg-MarQuardt方法逐步进行非线性多参数拟合的。在这个新模型中，适当地描述了磁层顶的不对称性和尖端附近的凹痕。此外，还考虑了IMF BZ对亚太阳距离的饱和效应以及对遥远的尾部磁层顶的外推。在该模型的基础上，次太阳距离对Pd+Pm的幂指数略小于−的1/6，北移的IMF BZ对磁层顶几乎没有影响，偶极子倾角对南北不对称性和凹陷位置有很大影响。与已有的基于我们数据库的经验磁层顶模型相比，新模型提高了对磁层顶三维结构的预测能力。结果表明，这一新模型可用于定量研究Pd+Pm对磁层顶的压缩、向南的IMF BZ对磁层顶的侵蚀以及偶极子倾角对南北不对称性和压痕的影响。
[1] A new three-dimensional asymmetric magnetopause model has been developed for corrected GSM coordinates and parameterized by the solar wind dynamic and magnetic pressures (Pd + Pm), the interplanetary magnetic field (IMF) Bz, and the dipole tilt angle. On the basis of the magnetopause crossings from Geotail, IMP 8, Interball, TC1, Time History of Events and Macroscale Interactions during Substorms (THEMIS), Wind, Cluster, Polar, Los Alamos National Laboratory (LANL), GOES, and Hawkeye, and the corresponding upstream solar wind parameters from ACE, Wind, or OMNI, this model is constructed by the Levenberg-Marquardt method for nonlinear multiparameter fitting step-by-step over the divided regions. The asymmetries of the magnetopause and the indentations near the cusps are appropriately described in this new model. In addition, the saturation effect of IMF Bz on the subsolar distance and the extrapolation for the distant tail magnetopause are also considered. On the basis of this model, the power law index for the subsolar distance versus Pd + Pm is a bit less than −1/6, the northward IMF Bz almost does not influence the magnetopause, and the dipole tilt angle is very important to the north–south asymmetry and the location of indentations. In comparison with the previous empirical magnetopause models based on our database, the new model improves prediction capability to describe the three-dimensional structure of the magnetopause. It is shown that this new model can be used to quantitatively study how Pd + Pm compresses the magnetopause, how the southward IMF Bz erodes the magnetopause, and how the dipole tilt angle influences the north–south asymmetry and the indentations.