Flexibility of a simple tropospheric gas phase reaction mechanism: investigations of a simulated experiment by inverse modelling published online: 13 August 2009

Inverse modelling was applied to computer simulated time series of trace gas concentrations as a means to design real experiments and to explore the potential of their real counterparts to deduce rate constants of a simplified reaction mechanism of tropospheric chemistry. Two cases were examined: As a first case, the model to be fitted was complete, but its rate constants were modified within the constraints from prior knowledge. For this case, we got a good fit and significantly improved the modified parameters. As a second case, an incomplete model, where an important reaction was omitted from the model, was fitted to the simulated experiment. For the incomplete model, we also got an apparently good fit, showing the flexibility of the mechanism. However, the hypothesis "mechanism is correct" had to be rejected because it is not consistent with the prior knowledge. The rejection was further confirmed by a simulated control experiment with different experimental constraints