with Baik, J., Bohnenstengel, S., Calmet, I., Chemel, C., Chen, F., Dandou, A., Fortuniak, K., Gouvea, M., Hamdi, R., Kondo, H., Krayenhoff, S., Lee, S., Loridan, T., Martilli, A., Masson, V., Miao, S., Oleson, K., Pigeon, G. Porson, A., Salamanca, F., Shashua-Bar, L., Steeveveld, G., Sugar, L., Trombou, M., Voogt, J., Zhang N

There are now a number of urban models within the community, which vary in complexity from simple schemes to the detailed representation of momentum and energy fluxes, even distributed within the atmospheric boundary layer. In addition to variations in complexity, these models also differ in parameter requirements and on a more practical level, the cost of running the models. Whilst many of these models have been validated against observational datasets, with some models even using the same observations, these have not been done in a controlled experiment that enables comparisons to be made between the models. Such controlled experiments, however, have been shown in the past to provide scientific insight into both the mechanics of the models and also the physics of the real world, for instance the PILPS experiments. This presentation will describe the progress that has been made so far with regards to an urban model comparison project.