Horizontal flow speed maps (one-hour averages) computed with time cadences Δt = 10–480 s (bottom to top) and Gaussian kernels with an FWHM = 400–1800 km (left to right). Displayed at the top of the panels are the mean speed and its standard deviation σ_v averaged over the FOV. The speed maps are scaled between 0.0–1.2 km s^-1, which corresponds to the scale used in Figs. 2 and 3. Axes are in megameters with the major tickmarks separated by 2 Mm.