Modeling and Simulation of Tropospheric Ozone Depletion in the Polar Spring

In polar spring, tropospheric ozone depletion is related to the presence of halogen oxide concentrations in the atmospheric boundary layer. Halogen oxides such as BrO participate in an autocatalytic chemical reaction cycle, leading to the release of Br₂ and BrCl from the fresh sea ice. The paper presents the identification of a detailed chemical reaction mechanism for the ozone depletion event, where bromine plays the major role. The heterogeneous reactions in the chemical reaction mechanism are studied in detail, and a sensitivity analysis is performed to identify the importance of each reaction in the mechanism. A skeletal reaction scheme is identified on the basis of the sensitivity analysis,. This skeletal chemical reaction mechanism then is used in a 3-D large eddy simulation (LES) with the Smagorinsky sub-grid model. The configuration studied includes a mountain located at the ground above which the ozone depletion is studied. In this situation, the height of the boundary layer varies, which greatly affects the ozone depletion event.