Seasonal Cycle of the Total Ozone Content over Southern High Latitudes in the CCM SOCOLv3

Several chemistry-climate models (CCM) tend to underestimate the total column ozone (TCO) over the southern polar region during winter. The most significant discrepancies were found in the CCM SOCOLv3, which we utilize to study the sensitivity of TCO over Antarctica to the following key influencing factors: (1) the efficiency of stratospheric heterogeneous reactions, (2) the intensity of meridional flux into the polar regions due to sub-grid scale mixing processes, and (3) the accuracy of photodissociation rate calculations. Comparisons of the model results with satellite observations from IKFS-2, MLS, and MIPAS showed that the most effective processes for improving polar ozone simulation are photolysis and horizontal mixing. An increase in horizontal mixing improves the simulated TCO seasonal cycle; however, it negatively impacts the representation of the CH4 and N2O distributions. The application of the photolysis module Cloud-J v.8.0 has improved the accuracy of photolysis rate calculations and the representation of the seasonal ozone cycle over the southern polar region. This paper outlines the impact of various processes on the performance of chemistry-climate models in the southern polar stratosphere, with potential implications for future advancements in this area.