Dynamic evolution of dayside magnetopause reconnection locations and
their dependence on IMF cone angle: 3-D global hybrid simulation
Abstract
We study the dynamic evolution of dayside magnetopause reconnection
locations and their dependence on the interplanetary magnetic field
(IMF) cone angle via 3-D global-scale hybrid simulations. Cases with
finite IMF Bx and Bz but By=0 are investigated. It is shown that the
dayside magnetopause reconnection is unsteady under quasi-steady solar
wind conditions. The reconnection lines during the dynamic evolution are
not always parallel to the equatorial plane even under purely southward
IMF conditions. Magnetopause reconnection locations can be affected by
the generation, coalescence, and transport of flux ropes (FRs),
reconnection inside the FRs, and the magnetosheath flow. In the presence
of an IMF component Bx, the magnetopause reconnection initially occurs
in high-latitude regions downstream of the quasi-perpendicular bow
shock, followed by the generation of multiple reconnection regions. In
the later stages of the simulation, a dominant reconnection region is
present in low-latitude regions, which can also affect reconnection in
other regions. The global distribution of reconnection lines under a
finite IMF Bx is found to not be limited to the region with maximum
magnetic shear angle.