Alho M, Battarbee M, Pfau-Kempf Y, Khotyaintsev Yu V, Nakamura R, Cozzani G, Ganse U, Turc L, Johlander A, Horaites K, Tarvus V, Zhou H, Grandin M, Dubart M, Papadakis K, Suni J, George H, Bussov M, Palmroth M
Department of Physics University of Helsinki Helsinki Finland.
Swedish Institute of Space Physics Uppsala Sweden.
Geophys Res Lett. 2022 Jul 28;49(14):e2022GL098329. doi: 10.1029/2022GL098329. Epub 2022 Jul 20.
Geospace plasma simulations have progressed toward more realistic descriptions of the solar wind-magnetosphere interaction from magnetohydrodynamic to hybrid ion-kinetic, such as the state-of-the-art Vlasiator model. Despite computational advances, electron scales have been out of reach in a global setting. eVlasiator, a novel Vlasiator submodule, shows for the first time how electromagnetic fields driven by global hybrid-ion kinetics influence electrons, resulting in kinetic signatures. We analyze simulated electron distributions associated with reconnection sites and compare them with Magnetospheric Multiscale (MMS) spacecraft observations. Comparison with MMS shows that key electron features, such as reconnection inflows, heated outflows, flat-top distributions, and bidirectional streaming, are in remarkable agreement. Thus, we show that many reconnection-related features can be reproduced despite strongly truncated electron physics and an ion-scale spatial resolution. Ion-scale dynamics and ion-driven magnetic fields are shown to be significantly responsible for the environment that produces electron dynamics observed by spacecraft in near-Earth plasmas.
地球空间等离子体模拟已经从磁流体动力学发展到混合离子动力学，朝着对太阳风-磁层相互作用更现实的描述迈进，比如最先进的Vlasiator模型。尽管计算技术有所进步，但在全球尺度上，电子尺度仍然难以企及。eVlasiator是一种新型的Vlasiator子模块，首次展示了由全球混合离子动力学驱动的电磁场如何影响电子，从而产生动力学特征。我们分析了与重联位点相关的模拟电子分布，并将其与磁层多尺度（MMS）航天器观测结果进行比较。与MMS的比较表明，关键的电子特征，如重联流入、加热流出、平顶分布和双向流，都非常吻合。因此，我们表明，尽管电子物理被大幅简化且空间分辨率为离子尺度，但许多与重联相关的特征仍能被重现。离子尺度动力学和离子驱动的磁场被证明对产生近地等离子体中航天器观测到的电子动力学环境负有重大责任。
