A theory is presented to explain tidally induced oscillations in the emission intensity I and rotational temperature T of the OH nightglow. The theory includes photochemical reactions among H, O, O3, OH, and HO2 and the complete dynamics of tides in an isothermal, uniformly rotating atmosphere. The ratio &eegr;=(ΔI/Ī)(ΔT/T¿) (Δ refers to a perturbation quantity and the overbar signifies an average) depends on basic state atmospheric structure, minor constituent scale heights, especially that of O, and altitude of OH emission. For both semidiurnal and diurnal migrating modes, &eegr; has an amplitude in the approximate range 1-2.5 and a phase between about 10¿ and 30¿. ¿ American Geophysical Union