# Rotation Effects

Including rotation in tidal response calculations is complicated by the fact that the traditional approximation of rotation doesn’t play well with forcing by the tidal potential $$\PhiT$$. As a result, for now only the Doppler shift due to rotation is included in gyre_tides calculations. This means that the frequency $$\sigma$$ appearing in the tidal equations is replaced by the co-rotating forcing frequency

(17)$\sigmac \equiv k \Oorb - m \Omega.$