  Recent theoretical, numerical, and observational work have suggested that
when a growing planet opens a gap in its disk the flow of gas into the gap is
dominated by gas falling vertically from a height of at least one gas scale
height. Our primary objective is to include, for the first time, the chemical
impact that accreting gas above the midplane will have on the resulting C/O. We
compute the accretion of gas onto planetary cores beginning at different disk
radii and track the chemical composition of the gas and small icy grains to
predict the resulting carbon-to-oxygen ratio (C/O) in their atmospheres. In our
model, all of the planets which began their evolution inward of 60 AU open a
gap in the gas disk, and hence are chemically affected by the vertically
accreting gas. Two important conclusions follow from this vertical flow: (1)
more oxygen rich icy dust grains become available for accretion onto the
planetary atmosphere. (2) The chemical composition of the gas dominates the
final C/O of planets in the inner ($<$ 20 AU) part of the disk. This implies
that with the launch of the James Webb Space Telescope we can trace the disk
material that sets the chemical composition of exoplanetary atmospheres.
