A two-dimensional (2D) photochemical model (latitude range from -85¿ to +85¿ and altitude range from the ground to 0.23 mbar (about 60 km)) has been used to investigate the influence of dynamics on model results. We tested three representations of atmospheric transport to simulate total ozone and 14C amounts after nuclear tests in the early 1960s. We also simulated three scenarios of NOx injections from a proposed fleet of stratospheric aircraft and their effects on ozone. The three dynamical formulations used were Dynamics A, a base dynamics used in previous work with this model; Dynamics B, a strong circulation dynamics discussed by Jackman et al. <1989a>; and Dynamics C, the dynamics used by Shia et al. <1989>. The advective component of the stratosphere to troposphere mass exchange rate (advective strat/trop exchange rate (ASTER)) is largest for Dynamics B (5.8¿1017 kg yr-1) and smallest for Dynamics C (1.4¿1017 kg yr-1), with the ASTER for Dynamics A (2.4¿1017 kg yr-1) being between these two extremes. Simulations of both total ozone and 14C were worst with Dynamics B. Simulations of total ozone were best with Dynamics A and for 14C best with Dynamics C. This illustrates the difficulty of simultaneously modeling constituents with different altitude and latitude dependencies. Ozone depletion from NOx injections of statospheric aircraft showed a strong sensitivity to dynamics. Generally, if eddy diffusion is not changed, then a large ASTER leads to reduced ozone loss while a small ASTER leads to increased ozone loss from a given stratospheric NOx injection. ¿ American Geophysical Union 1991