Longitudinal power spectra of the radial kinetic energy density, ${\stackrel{\sim }{E}}_{\mathrm{kin}}^r$, near the surface r = 0.98 R for a narrow latitudinal band around the equator (± 7.5°). The colors indicate the run sets and the line styles/symbols the run type: solid/asterisk (M), dashed/diamonds (H) and dotted/triangles (S). The spectra are averaged over the θ bands and time. The inlay shows the m value of the maxima as a function of Re for all runs. The errors are calculated using an 80% range around the peak. The values m = 32 and m = 40 are indicated by black vertical and (in inlay) red horizontal lines, respectively.