Glocer A, Toth G, Fok M-C
NASA/GSFC, Greenbelt, Maryland, USA.
Climate and Space Sciences and Engineering, University of Michigan,Ann Arbor, MI, USA.
J Geophys Res Space Phys. 2018 Apr;123(4):2851-2871. doi: 10.1002/2018JA025241. Epub 2018 Mar 23.
We present a new expansion of the Polar Wind Outflow Model (PWOM) to include kinetic ions using the Particle-in-Cell (PIC) approach with Monte Carlo collisions. This implementation uses the original hydrodynamic solution at low altitudes for efficiency, and couples to the kinetic solution at higher altitudes to account for kinetic effects important for ionospheric outflow. The modeling approach also includes wave-particle interactions, suprathermal electrons, and an hybrid parallel computing approach combining shared and distributed memory paralellization. The resulting model is thus a comprehensive, global, model of ionospheric outflow that can be run efficiently on large supercomputing clusters. We demonstrate the model's capability to study a range of problems starting with the comparison of kinetic and hydrodynamic solutions along a single field line in the sunlit polar cap, and progressing to the altitude evolution of the ion conic distribution in the cusp region. The interplay between convection and the cusp on the global outflow solution is also examined. Finally, we demonstrate the impact of these new model features on the magnetosphere by presenting the first 2-way coupled ionospheric outflow-magnetosphere calculation including kinetic ion effects.
我们提出了极地风流出模型（PWOM）的一种新扩展，使用具有蒙特卡罗碰撞的粒子模拟（PIC）方法来纳入动力学离子。这种实现方式在低高度使用原始的流体动力学解以提高效率，并在较高高度与动力学解耦合，以考虑对电离层流出重要的动力学效应。建模方法还包括波粒相互作用、超热电子以及一种结合共享内存和分布式内存并行化的混合并行计算方法。由此产生的模型是一个全面的、全球电离层流出模型，能够在大型超级计算集群上高效运行。我们展示了该模型研究一系列问题的能力，首先是比较日光照耀的极盖区单条磁力线上的动力学解和流体动力学解，然后是研究尖点区域离子圆锥分布的高度演化。还研究了对流和尖点在全球流出解上的相互作用。最后，通过展示包括动力学离子效应的首次双向耦合电离层流出 - 磁层计算，我们证明了这些新模型特征对磁层的影响。
