EVALUATING CHEMICAL-TRANSPORT MODELS - COMPARISON OF EFFECTS OF DIFFERENT CFC-11 EMISSION SCENARIOS

In this study we compare the results of model simulations of CFC-11 in the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM2) with two different published emission distributions. We find that for predicted CFC-11 concentrations at the Atmospheric Lifet ime Experiment/Global Atmospheric Gases Experiment (ALE/GAGE) observat ion sites there is very little difference resulting from the two distr ibutions. However, the difference is apparent in major transport event s such as pollution events. This has important implications for assess ment of regional emissions from a sparse network like ALE/GAGE using i nverse methods. It also implies that differences between modeled and o bserved CFC-11 concentrations are due predominantly to model transport errors not model emission errors.