A New Spin On Tropospheric Ozone Production

Abstract:

Attributing the differences between models in the calculated concentrations and production rate of tropospheric ozone to differences in model processes has historically been difficult. We suggest that a new model diagnostic approach based on the conservation of quantum mechanical spin may allow a more informed comparison between models. This approach considers the allowed processing of the spin-paired electrons, which are emitted into the atmosphere through VOC emissions, the impact of spin-conservation rules on radical generation and then the fraction of radicals that react to give ozone. This accounting readily links large-scale model processes (emissions, chemical scheme, deposition) to the model ozone production. We discuss this new diagnostic in terms of the GEOS-Chem model and its response to changes in NOx and VOC emissions. This new diagnostic methodology may enable more informative model-model comparisons of tropospheric ozone production.