The evolution of ozone has been calculated for the winters of 1979 and 1989 using winds derived from our stratospheric data assimilation system (STRATAN). The ozone fields calculated using this technique are found to compare well with satellite-measured fields for simulations of 2--3 months. Here we present comparisons of model fields with both satellite and sonde measurements to verify that stratospheric transport processes are properly represented by this modeling technique. Attention is focused on the northern hemisphere middle and high latitudes at the 10-hPa level and below, where transport processes are most important to the ozone distribution. First-order quantities and derived budgets from both the model and satellite data are presented. By sampling the model with a limb-viewing satellite and then Kalman filtering the ''observations'' of the model, it is shown that transient subplanetary-scale features that are essential to the ozone budget are missed by the satellite systems. ¿ American Geophysical Union 1991