In an effort to understand the behavior of ozone in the transition region, the terms in the perturbation continuity equation have been evaluated from solar backscattered ultraviolet ozone data, National Meteorological Center temperature data, and geostrophic winds derived from the temperature data at 2 mbar, winter 1978-1979. A linear parameterization is used to estimate the chemical source term. The perturbation ozone field calculated by integrating the net forcing evaluated from the data compares well with the measured perturbation ozone field. There are occasions during the winter when the sum of the dynamic terms is small due to cancellation, and the ozone and temperature perturbations are anticorrelated. The -1 correlation between the ozone and temperature perturbations does not necessarily imply that chemical forcing is dominant.