Vorticity as a function of divergence for the average supergranule at 40° latitude from HMI data. a) Vorticity travel times τ^ac versus divergence travel times τ^oi for TD f modes and p₁ modes. The upper left quadrant shows the values for the average outflows, the lower right quadrant for the average inflows. The solid and the dashed lines show least-squares fits of a linear function through the origin for outflows and inflows, respectively. The error bars were obtained by dividing the 336 datasets into eight parts. b) As a) but the peak ω_z versus the peak div_h from LCT is shown. We note that the quadrants depicting outflows and inflows are flipped compared to the travel times in a).