Échelle diagram overlaid on the amplitude spectrum with a colored background scale. The filled symbols (white and orange) represent the identified modes for ℓ = 0 (circles), ℓ = 1 (triangles) and ℓ = 2 (squares). The orange symbols are the frequencies shifted for the daily gap of  ± 11.57 μHz while the open symbols correspond to the original unshifted values. The ridges derived from the fit to the asymptotic relation (4) are also marked.