磁云边界层中的复合重联喷流观测分析

太阳风中的磁场重联通常与行星际日冕物质抛射有关.本文分析了1995年10月18日WIND飞船观测到的一例磁云前边界层中的复合重联喷流事件.该复合排空区由相邻两个不同方向的喷流构成,这两个喷流分别经过Walen关系的证认,符合行星际磁场重联排空区等离子体喷流的特征.结果表明,在磁云前端可能存在众多重联点,从而将磁云本体的磁场剥离,形成比单一重联喷流区更复杂的三维边界层结构.磁云边界层中可能发生多点多次重联,从而不表现出单点重联的排空区特征,这可能是行星际磁场重联排空区较少在ICME前端被观测到的原因之一.

Observation of a Dual Reconnection Exhaust Inside the Boundary Layer of Magnetic Cloud at 1 AU

Magnetic reconnection is prevalent in the low speed and low proton beta solar wind and is usually associated with Interplanetary Coronal Mass Ejections (ICME). In this paper, a dual reconnection exhaust in the front boundary of a Magnetic Cloud (MC) was observed by WIND spacecraft on 18 October 1995. The Alfvénic accelerated or decelerated plasma jets were examined using Walén relation near the boundary of the exhausts, which are consistent with the characteristics of the interplanetary reconnection exhausts reported in recent literatures. As a consequence, multiple reconnection exhausts could be abundant ahead of the MCs and complex 3D boundary layers would form instead of single reconnections exhausts. Such complex structures may bring some difficulties in searching for reconnection events in the magnetic cloud boundary layers.