Helmholtz decomposition of the radially averaged (over the outer and mid atmosphere) horizontal wind of three, synchronous, HD 209458b-like atmospheric models with rotation rates ranging from 0.125Ω₀ to 15Ω₀. The top row plots the divergent component (H_diυ) of the Helmholtz decomposition, the middle row plots the rotational component (H_rot) of the decomposition, and the bottom row shows the eddy component (H_eddy = H_rot − 〈H_rot〉) of the decomposition. We note the change (decrease) in RMS mean velocity as the rotation rate increases.