Offsets between P-angle corrected and uncorrected δτ_SN measured from MDI data as a function of travel distance Δ. A negative value corresponds to a southward flow owing to the P-angle error. The offsets in δτ_SN are averaged over 10° bands around selected latitudes as labeled in the legend. Gaussian smoothing, with FWHM = 7.2° in Δ, is applied here. The errors of only one curve, computed from the standard errors of the mean within each 7.2° segment, are shown with dashed lines and those of other curves are similar. The black solid line is a ray approximation of travel-time differences arising from a simple model of the leaking flow described in the text. The corresponding radii of lower turning points from the ray approximation are indicated at the top.