Frequency shifts, ⟨ Δν_{n,l = 0} ⟩, ⟨ Δν_{n,l = 1} ⟩, ⟨ Δν_{n,l = 2} ⟩, at each individual angular degree l = 0, 1, and 2 (from left to right), as a function of the corresponding 10.7 cm radio flux, F_10.7, and calculated for three different frequency ranges once the QBO signature was removed. From top to bottom, the frequency ranges are the following: a) 1800 μHz ≤ ν< 3790μHz; b) 1800 μHz ≤ ν< 2450μHz (low-frequency range); and c) 3110 μHz ≤ ν< 3790μHz (high-frequency range). The rising (black dots) and declining (blue dots) phases of Cycle 23, and the rising phase (red dots) of Cycle 24 are indicated by different colors.