标题： 日侧电离层的东向传播现象 II：类似平行板电容器效应 显示英文标题

标题： Eastward Transients in the Dayside Ionosphere II: A Parallel-plate Capacitor-Like Effect

摘要： 2023年4月23日的地磁暴期间，我们观测到在白昼磁层闭合磁场线上由等离子体波驱动的高能粒子沉降现象。 同时，在电离层底部，通过米级湍流的雷达探测，我们观测到电离层电场的电离效应和显著增强的特征，并且这些特征与磁层观测的时间特性相匹配。 我们在一篇后续论文中详细描述了这一现象。 在本文中，我们将这些观测结果置于白昼电离层背景下进行分析，并描述了一次发生在2024年5月的地磁超级风暴中非常相似的事件。 在这两种情况下，快速向东移动的电场结构均在电离层极尖区以南的闭合磁力线中被激发——这一观测结果挑战了目前对极盖区电磁动力学的传统解释方式，而大多数此类观测通常被解读为向极地方向移动的极光形式的结果。 相反，主要向东移动的电场结构与湍流霍尔电流相关联，这种电流可能是在地磁风暴期间由靠近磁层赤道区域的波粒相互作用或者极盖区的质子沉降特性所特异性激发的，形成了类似“平行板电容器效应”的现象。 我们提出，白昼电离层中的短暂向东电磁爆发可能是地磁暴的一个常见但之前未被充分认识的特征。 显示英文摘要

摘要： During the 23 April 2023 geospace storm, we observed chorus wave-driven, energetic particle precipitation on closed magnetic field lines in the dayside magnetosphere. Simultaneously and in the ionosphere's bottom-side, we observed signatures of impact ionization and strong enhancements in the ionospheric electric field, via radar-detection of meter-scale turbulence, and with matching temporal characteristics as that of the magnetospheric observations. We detailed this in a companion paper. In the present article, we place those observations into context with the dayside ionosphere, and describe a remarkably similar event that took place during the May 2024 geospace superstorm. In both cases, fast, eastward-moving electric field structures were excited equatorward of the ionospheric cusp, on closed magnetic field-lines -- observations that challenge existing modes of explanation for electrodynamics in the cusp-region, where most such observations are interpreted in the context of poleward-moving auroral forms. Instead, primarily eastward-moving electric field structures were associated with turbulent Hall currents that are perhaps characteristically excited during geospace storms by wave-particle interactions near magnetospheric equator or by proton precipitation characteristics in the cusp, forming a `parallel-plate capacitor-like effect'. We propose that transient eastward electrodynamic bursts in the dayside ionosphere might be a common, albeit previously unresolved, feature of geomagnetic storms.