Upper left: power spectra of f_fast as a function of height and frequency for the BATT run. For better visualization, the maps are scaled with a factor of ρ₀, the density of the unperturbed atmosphere. The power is shown in log₁₀ units of J m⁻⁵ Hz⁻¹. Upper right panels: ratio of power between the AMBI and BATT, AMBIHALL and BATT, and AMBIHALL and AMBI runs. Contours mark the locations where the power ratio is unity. Bottom panels: same, but for f_alf.