Plasma convection on a global scale is a fundamental feature of planetary magnetosphere. The Dungey cycle explains that steady-state convection within the closed part of the magnetosphere relies on magnetic reconnection in the nightside magnetospheric tail. Nevertheless, time-dependent models of the Dungey cycle suggest an alternative scenario where magnetospheric convection can be solely driven by dayside magnetic reconnection. In this study, we provide direct evidence supporting the scenario of dayside-driven magnetosphere convection. The driving process is closely connected to the evolution of Region 1 and Region 2 field-aligned currents. Our global simulations demonstrate that intensified magnetospheric convection and field-aligned currents progress from the dayside to the nightside within 10–20 minutes, following a southward turning of the interplanetary magnetic field. Observational data within this short timescale also reveal enhancements in both magnetosphere convection and the ionosphere’s two-cell convection. These findings provide insights into the mechanisms driving planetary magnetosphere convection, with implications for the upcoming Solar-Wind-Magnetosphere-Ionosphere Link Explorer (SMILE) mission.

全球范围内的等离子体对流是行星磁层的基本特征。邓吉循环解释说，磁层封闭部分内的稳态对流依赖于夜侧磁层尾部的磁重联。然而，邓吉循环的时间相关模型提出了另一种情况，其中磁层对流可以仅由日侧磁重联驱动。在这项研究中，我们提供了支持白天驱动磁层对流情景的直接证据。驱动过程与区域 1 和区域 2 场对准电流的演变密切相关。我们的全球模拟表明，在行星际磁场南转后，增强的磁层对流和场对准电流会在 10-20 分钟内从白天发展到夜晚。如此短的时间尺度内的观测数据还揭示了磁层对流和电离层双细胞对流的增强。这些发现为驱动行星磁层对流的机制提供了见解，对即将到来的太阳-风-磁层-电离层链接探索者（SMILE）任务具有重要意义。