Upper panel: (a) Time series of the velocity component variations V_x at y = 0.1 Mm. Time t = 0 corresponds to t = 60 s after the start of the simulation. (b) Wavelet power spectrum of the V_x time series. The solid line is the cone of influence. (c) Global wavelet power spectrum with a confidence level of 95% marked by the dashed red line. Bottom panel: Comparison of time series of variations in the velocity component, V_x at y = 3 Mm, 1 Mm.