Ala-Lahti Matti, Pulkkinen Tuija I, Pfau-Kempf Yann, Grandin Maxime, Palmroth Minna
Department of Climate and Space Sciences and Engineering University of Michigan Ann Arbor MI USA.
Department of Physics University of Helsinki Helsinki Finland.
Geophys Res Lett. 2022 Oct 16;49(19):e2022GL100079. doi: 10.1029/2022GL100079. Epub 2022 Oct 5.
Solar wind-magnetosphere coupling drives magnetospheric dynamic phenomena by enabling energy exchange between magnetospheric and solar wind plasmas. In this study, we examine two-dimensional noon-midnight meridional plane simulation runs of the global hybrid-Vlasov code Vlasiator with southward interplanetary magnetic field driving. We compute the energy flux, which consists of the Poynting flux and hydrodynamic energy flux components, through the Earth's magnetopause during flux transfer events (FTEs). The results demonstrate the spatiotemporal variations of the energy flux along the magnetopause during an FTE, associating the FTE leading (trailing) edge with an energy injection into (escape from) the magnetosphere on the dayside. Furthermore, FTEs traveling along the magnetopause transport energy to the nightside magnetosphere. We identify the tail lobes as a primary entry region for solar wind energy into the magnetosphere, consistent with results from global magnetohydrodynamic simulations and observations.
太阳风-磁层耦合通过实现磁层与太阳风等离子体之间的能量交换来驱动磁层动态现象。在本研究中，我们使用向南的行星际磁场驱动，对全球混合-Vlasov代码Vlasiator进行二维午-子夜子午面模拟运行。我们计算了通量传输事件（FTEs）期间通过地球磁层顶的能量通量，其由坡印廷通量和流体动力学能量通量分量组成。结果展示了FTE期间能量通量沿磁层顶的时空变化，将FTE的前缘（后缘）与向日侧磁层的能量注入（逃逸）联系起来。此外，沿磁层顶传播的FTE将能量传输到夜侧磁层。我们确定尾瓣是太阳风能量进入磁层的主要入口区域，这与全球磁流体动力学模拟和观测结果一致。
