Temporal variations of zonal anomalies near Aphrodite Terra (5°S-15°S). A 5-Venus-day Gaussian smoothing is applied along the Venus date axis, followed by thermal tide removal via harmonic fitting at each smoothed field within the 5°S-15°S latitude band. Panel a : brightness temperatures. Panel b : zonal winds. Panel c : meridional winds. Color shading indicates deviations from the zonal mean. The red rectangles indicate the regions where the longitudinal contrasts are reduced over time. Gray areas indicate regions without data.