  We measure the mean frequencies of acoustic waves propagating toward and away
from a sunspot employing a spot-centered Fourier-Hankel decomposition of p-mode
amplitudes as measured from a set of observations made at the South Pole in
1991. We demonstrate that there is a significant frequency shift between the
inward and outward traveling waves which is consistent with the Doppler effect
of a radial outflow from the sunspot. For p-modes of temporal frequencies of 3
mHz it is observed that the frequency shift decreases slightly with spatial
frequency, for modes with degree l between 160 to 600. From the l dependence of
the frequency shift, we infer that the mean radial outflow within the observed
annular region (which extends between 30 and 137 Mm from the spot) increases
nearly linearly with depth, reaching a magnitude of about 200 m/s at a depth of
20 Mm. This outflow exhibits properties similar to flows recently reported by
Lindsey, et al. (1996) using spatially sensitive local helioseismic techniques.
