Spatial turbulent spectrum and turbulent frequency. Left: Spatial turbulent spectrum, E_iso(k), extracted from solar observations (solid blue line). The spectrum comprises roughly three sections, each with a different power law in k^α. The dashed orange line shows the best fit of the data to a three-piece-wise power law. The exponents and the boundaries between the three regimes are indicated on the plot. Right: Turbulent frequency ω_k ≡ ku_k as a function of wavenumber, k, where u_k is the typical velocity of the turbulent eddies of inverse size k, given by Eq. (47).