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Geosci. Model Dev. Discuss., 5, 1949-1985, 2012
www.geosci-model-dev-discuss.net/5/1949/2012/ doi:10.5194/gmdd-5-1949-2012 © Author(s) 2012. This work is distributed under the Creative Commons Attribution 3.0 License. |
Tagged ozone mechanism for MOZART-4, CAM-chem, and other chemical transport models
1Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, CO, USA
2Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
Abstract. A procedure for tagging ozone produced from NO sources through updates to an existing chemical mechanism is described, and results from its implementation in the Model for Ozone and Related chemical Tracers (MOZART-4), a global chemical transport model, are presented. Artificial tracers are added to the mechanism, thus not affecting the standard chemistry. The results are linear in the troposphere, i.e., the sum of ozone from individual tagged sources equals the ozone from all sources to within 3% in zonal mean monthly averages. The stratospheric ozone contribution to the troposphere determined from the difference between total ozone and ozone from all tagged sources is significantly less than estimates using a traditional stratospheric ozone tracer (8 vs 20 ppbv at the surface). The commonly used technique of perturbing NO emissions by 20% in a region to determine its ozone contribution is compared to the tagging technique, showing that the tagged ozone is 2–4 times the ozone contribution that was deduced from perturbing emissions.
Citation: Emmons, L. K., Hess, P. G., Lamarque, J.-F., and Pfister, G. G.: Tagged ozone mechanism for MOZART-4, CAM-chem, and other chemical transport models, Geosci. Model Dev. Discuss., 5, 1949-1985, doi:10.5194/gmdd-5-1949-2012, 2012.