第八期:Turbulent magnetic reconnection in the solar wind

讲座信息

讲座题目:Turbulent magnetic reconnection in the solar wind

讲座嘉宾:王荣生(中国科技大学地球和空间科学学院)

时间:待定

地点:北航沙河主楼D座10层东

讲座摘要

In the process of magnetic reconnection, magnetic field lines on both sides of the current sheet move inward to form an X-line magnetic topology. In the terrestrial magnetosphere, reconnection is generally bursty with many magnetic flux ropes, and magnetic energy is rapidly released in the vicinity of the X-line region and the resulting bursty flows affect large volumes. In contrast, previous observations show that the reconnection is quasi-steady-state in the solar wind and the energy is primarily dissipated via slow-mode shocks bounding the exhausts, i.e., the Petschek-like reconnection. The reason for such difference is elusive. Here, we present direct measurement of bursty and turbulent reconnection in the solar wind and a preceding crossing of exhausts bounded by a pair of slow-mode shocks near the switch-off limit. The X-line region is filled with filamentary currents and magnetic flux ropes which are rapidly evolving and closely interacting as they are being ejected away. The plasma is more efficiently heated in the diffusion region than across the shocks and the bulk flow enhancement is primarily accomplished in the exhausts rather than the diffusion region. A statistical analysis shows that the bursty reconnection can be intrinsic in the solar wind and largely contributes to the solar wind acceleration and heating.

嘉宾介绍

中国科技大学教授,博士生导师,主要研究方向为无碰撞磁重联及相关物理问题,累计发表论文60余篇,以第一或通讯作者在Nature Physics, Nature Communications, Phys.Rev.Lett., Geophys.Res.Lett., J.Gephys.Res.,等国际国内期刊发表SCI论文30余篇;曾获得2010年度中国科学院院长优秀奖,2011年度中国科学院优秀博士论文,2019年度亚太等离子物理联盟 U40奖,2019年国家自然科学基金委优秀青年基金资助。