  Flux transfer events (FTEs) are a type of magnetospheric phenomena that
exhibit distinctive observational signatures from the in-situ spacecraft
measurements across the Earth's magnetopause. They are generally believed to
possess a magnetic field configuration of a magnetic flux rope and formed
through magnetic reconnection at the dayside magnetopause, sometimes
accompanied with enhanced plasma convection in the ionosphere. We examine two
FTE events under the condition of southward interplanetary magnetic field (IMF)
with a dawn-dusk component at the magnetopause by applying the Grad-Shafranov
(GS) reconstruction method to the in-situ measurements by the Magnetospheric
Multiscale (MMS) spacecraft to derive the magnetic flux contents associated
with the FTE flux ropes. In particular, given a cylindrical magnetic flux rope
configuration derived from the GS reconstruction, the magnetic flux content can
be characterized by both the toroidal (axial) and poloidal fluxes. We then
estimate the amount of magnetic flux (i.e., the reconnection flux) encompassed
by the area ``opened" in the ionosphere, based on the ground-based Super Dual
Auroral Radar Network (SuperDARN) observations. We find that for event 1, the
FTE flux rope is oriented in the approximate dawn-dusk direction, and the
amount of its poloidal magnetic flux agrees with the corresponding reconnection
flux. For event 2, the agreement among the estimates of the magnetic fluxes is
uncertain. We provide a detailed description about our interpretation for the
topological features of the FTE flux ropes, based on a formation scenario of
sequential magnetic field reconnection between adjacent field lines, consistent
with our results.
