Nonlobe Reconnection at the Earth's Magnetopause for Northward IMF

Under northward interplanetary magnetic field conditions, magnetic reconnection at the Earth's magnetopause is usually thought to operate through the merging of magnetosheath magnetic field lines and open magnetic field lines from the magnetospheric lobe. However, reconnection also occurs between magnetosheath field lines and closed magnetic field lines in the magnetosphere. Under certain conditions, this nonlobe field line reconnection has distinct plasma and magnetic field signatures that distinguish it from reconnection of lobe field lines. A survey of these conditions suggests that nonlobe reconnection at the Earth's magnetopause may be common even for relatively strong northward IMF. Plain Language Summary Magnetic reconnection interconnects magnetic field lines across a current sheet like that at the Earth's magnetopause or like that in the solar corona. This paper describes a type of interconnection of magnetic field lines at the magnetopause that was first reported for the solar corona. It appears that this type of reconnection is fairly common at the magnetopause. The different topology of this reconnection suggests a different type of interaction between the magnetic field lines in the solar wind and the field lines of the Earth.