  We detect near-infrared H2 emission in DG Tau using the Infrared Camera and
Spectrograph (IRCS) on the 8.2-m SUBARU telescope. The spectra obtained along
the jet axis show that the centroidal position of the 1-0 S(1) emission is
offset by 0.2" from the star towards the jet, while those obtained
perpendicular to the jet axis show a marginal extension, indicating that the
emission line region has a typical width of ~0.6". Their line profiles show a
peak velocity of ~15 km s^-1 blueshifted from the systemic velocity. These
results indicate that the emission originates from a warm molecular wind with a
flow length and width of ~40 and ~80 AU, respectively. The line flux ratios
I_{1-0 S(0)}/I_{1-0 S(1)} and an upper limit for I_{2-1 S(1)}/I_{1-0 S(1)})
suggest that the flow is thermalized at a temperature of ~2000 K, and is likely
heated by shocks or ambipolar diffusion. The observed velocity and spatial
extension suggest that the H2 and forbidden line emission originate from
different components of the same flow, i.e., a fast and partially ionised
component near the axis and a slow molecular component surrounding it. Such a
flow geometry agrees with model predictions of magneto-centrifugal driven
winds.
