Improving the GEOS-Chem Model to Better Predict Ozone Concentrations in the Arctic.

Sea ice in the Arctic is rapidly retreating and these changes can affect the global atmosphere and its chemistry. As sea ice changes, its effects on halogen activation could greatly alter ozone concentrations through ozone depletion events (ODEs). Ozone is the main precursor to atmospheric oxidation and its removal from the atmosphere can have large consequences. As climate changes, it is important to understand and predict the effects of retreating sea ice on tropospheric ozone. To accomplish this, we assess the ability of the GEOS-Chem model to predict ozone concentrations over the Arctic Ocean. By using the current model configuration and applying statistical methods to quantify model biases, errors, and correlations with observations recorded by the O-Buoy project, we can assess the capabilities of the model. Through exploratory data analysis we can identify conditions under which the model performs especially well or poorly. Current global models inadequately predict ozone concentrations in the Arctic during springtime. This is mostly likely due to a lack of understanding of reactive halogen chemistry. It is our goal to test hypotheses of processes that could be missing from the GEOS-Chem model that would explain the discrepancies from the observations. By improving the model, we can better predict a changing Arctic climate.