Asymmetric interaction of a solar wind reconnecting current sheet and
its magnetic hole with Earth's bow shock and magnetosphere
Abstract
We report results of our analysis of a solar wind reconnecting current
sheet (RCS) and its solar wind magnetic hole observed on 20 November
2018. In the solar wind, the normal vector to the current sheet plane
makes an angle of 32° with the Sun-Earth line. A combination of tilted
current sheet plane and foreshock effects cause an asymmetric
interaction with the bow shock, such that the structure arrives at the
quasi-perpendicular side of the bow shock before the quasi-parallel
side. The solar wind flow slowdown and deflection during the bow shock
crossing significantly disrupt the reconnection exhausts within the RCS.
Unlike localized magnetosheath jets, the solar wind RCS has a global
impact on the bow shock and the magnetopause. Plasma flow deflection in
the magnetosheath also increases with the passage of the RCS. The
magnetic field strength inside the magnetic hole decreases by
~69 percent in the solar wind, with a similar depression
rate observed inside the magnetosheath due to this structure. The ion
density and temperature both increase within the current sheet to form a
roughly pressure balanced structure. Field rotation and change in the
dynamic pressure during this event modify the reconnection zones at the
magnetopause and cause an inward motion of this boundary.