  The disk around HD 169142 has been suggested to host multiple embedded
planets due to the range of structures observed in the dust distributions. We
analyze archival ALMA observations of $^{12} \mathrm{CO \ (2-1)}$, $^{13}
\mathrm{CO \ (2-1)}$, and $\mathrm{C}^{18} \mathrm{O \ (2-1)}$ to search for
large-scale kinematic structures associated with other embedded planets in the
outer disk. At 125 au, we identify a coherent flow from the disk surface to the
midplane, traced by all three CO isotopologues, and interpret it as a
meridional flow, potentially driven by an embedded planet. We use changes in
the rotation speed of the gas to characterize the physical structure across
this region, finding that at 125 au the CO emission traces regions of increased
gas pressure, despite being at a surface density minimum. Developing a simple
analytical model, we demonstrate that the physical structure of the gap can
have non-trivial responses to changes in the surface density, consistent both
with previous thermo-chemical models, and the conditions inferred
observationally. Applying this technique to a range of sources will allow us to
directly confront theoretical models of gap-opening in protoplanetary disks.
