通量传输事件（FTEs）是行星际磁场与行星磁层磁场重联产生的磁通量管结构，构成太阳风向行星磁层传输磁通量和等离子体的有效通道。卫星实地观测FTEs产生率及空间分布规律是理解大尺度磁重联和磁通量传输效率的关键。地球磁层的大量卫星数据促使FTEs被广泛地研究，但水星磁层探测数据的缺乏导致该类研究始终没有系统化。水星偶极磁层比地球小且磁场较弱，周围行星际磁场更强并且以径向分量为主，因此其磁重联和磁通量传输特征应当与地球不同。本项目拟利用美国新的水星探测计划“信使”号的长期探测数据，通过统计分析行星际磁场，尤其是径向分量，对FTEs产生率及空间分布的影响，来揭示水星磁层顶FTEs产生率及空间分布规律。进一步与地球空间已有结果比较，明确行星际磁场径向分量对FTEs产生及空间分布的控制作用。以期在不同行星空间环境下磁层顶重联动力学特征的普遍规律上获得新的认识。

Flux transfer events (FTEs) refer to the magnetic flux ropes, formed through magnetic reconnection (MR) of the magnetospheric and magnetosheath magnetic fields at planetary magnetopauses. Such flux ropes offered channels for the transport of the solar wind magnetic flux and plasma into planetary space. The in situ observations of FTEs reoccurrence rate and spatial distribution provide a crucial key to understand the large-scale MR and the magnetic flux transport rate. The characteristic of FTEs reoccurrence rate and spatial distribution at Earth’s magnetopause have been extensively studied, however, so far, this research has not been systematic conducted at Mercury due to lack of sufficient observational data for a long time. Comparing with the Earth, Mercury has weaker intrinsic magnetic field. Nevertheless, the interplanetary magnetic field (IMF) at Mercury orbit is much stronger and mainly in radial direction. Therefore, the signatures of MR and magnetic flux transport are expected to be largely different from each other. Based on the large MESSENGER database, this project will statistically study how the IMF, especially its radial component, controls the FTEs reoccurrence rate and spatial distribution at Mercury’s magnetopause. Further, the obtained results will be compared with the present knowledge of the Earth case. The role of radial IMF in controlling magnetic flux transport rate will be defined. New understandings of the different planetary magnetopause dynamics will be gained from this project.