  The infrared young stellar outflow source MHO 3252 Y3 in the Serpens South
star-forming region was found to be variable. The available photometric data
can be fitted with a double peaked light curve of 904 d period. Color
variations are consistent with variable extinction with a flatter wavelength
dependence than interstellar extinction, i.e., larger grains. MHO 3252 Y3 is
the source of a large scale bipolar outflow, but the most recent outflow
activity has produced a microjet detectable in the shock excited H_2 1--0 S(1)
line while [FeII] emission appears confined to the immediate vicinity of the
central star. The proper motion of individual shock fronts in the H_2 microjet
has been measured and traces these knots back to ejection events in the past
two centuries. Integral field spectroscopy with the Keck 1 adaptive optics
system and the OSIRIS instrument shows velocity components near the launch
region that are distinct from the microjet both in radial velocity and apparent
proper motion. They match the prediction of dual wind models with a distinct
low velocity disk wind component. We find evidence for the entrainment of this
low velocity component into the high velocity microjet, leading to shock
excited emission at intermediate velocities in an envelope around the microjet.
