Presents a theoretical interpretation with the purpose of better understanding the chemical behaviour of the stratosphere and the coupling between temperature and ozone concentrations, when a periodic forcing is applied to the solar ultraviolet (UV) flux. The response of the temperature and of the trace species concentrations, including ozone, to short-term variations in the solar UV irradiance is calculated by a one-dimensional chemical-radiative time- dependent model. Comparison of the model results with the observed ozone and temperature responses, based on satellite data, shows that the theory is consistent in many respects with observations.