Magnetic reconnection between open and closed magnetic field in the corona is
believed to play a crucial role in the corona/heliosphere coupling. At large
scale, the exchange of open/closed connectivity is expected to occur in
pseudo-streamer structures. However, there is neither clear observational
evidence of how such coupling occurs in pseudo-streamers, nor evidence for how
the magnetic reconnection evolves. Using a newly-developed technique, we
enhance the off-limb magnetic fine structures observed with AIA and identify a
pseudo-streamer-like feature located close to the northern coronal hole. After
extrapolating the magnetic field with the PFSS model, we obtain a
pseudo-streamer magnetic topology, null-point related topology bounded by open
field. We compare the magnetic configuration with the UV observations and
identify the magnetic structures expected to be involved in the event. Using an
3D MHD simulation of interchange reconnection, we showed that the evolution of
the UV structures follows the magnetic field dynamics and the UV emitting
structures have a pattern very similar to the plasma emission derived from the
simulation. Our results highlight that the exchange between open and closed in
the pseudo-streamer topology related to an observed event occurs at least
partially at the null-point, similarly to the interchange reconnection in a
single null-point topology. However, our results also indicate that the
interchange reconnection in pseudo-streamers is a gradual physical process
which opposes to the impulsive reconnection of the solar-jet model