Peak v^ac and ω_z values for the average supergranule at different solar latitudes. a) Circulation velocity v^ac for LCT, f modes, and p₁ modes. b) Vertical component of flow vorticity ω_z obtained from LCT. Solid lines are for the average supergranule outflow region, dashed lines for the average supergranule inflow region. At 0° latitude, the values at the map center are shown instead of the peak values. The error bars were computed by dividing the 336 datasets into eight parts and measuring the variance of v^ac and ω_z at the peak positions over the eight parts.