CMIP5 Models of North American Climate
Sheffield, J., Barrett, A.P., Colle, B., Fernando, D.N., Fu, R., Giel, K.L., Hu, Q., Kinter, J., Kumar, S., Langenbrunner, B., Lombardo, K., Long, L.N., Maloney, E., Mariotti, A., Meyerson, J.E., Mo, K.C., Neelin, J.D., Nigam, S., Pan, Z., Ren, T., Ruiz-Barradas, A., Serra, Y.L., Seth, A., Thibeault, J.M., Stroeve, J.C., Yang, Z. and Yin, L. 2013. North American climate in CMIP5 experiments. Part I: Evaluation of historical simulations of continental and regional climatology. Journal of Climate 26: 9209-9245.
In an effort to determine if the CMIP5 models were indeed beter performers than the CMIP3 models, Sheffield et al. evaluated the abilities of these models to reproduce in retrospect a number of observational data sets. Their analysis focused on a core set of 17 CMIP5 models that "represent a large set of climate centers and model types." And what did they learn?
The 27 researchers report "the performance of the CMIP5 models in representing observed climate features has not improved dramatically compared to CMIP3." They note, for example, "there are some models that have improved for certain features (e.g., the timing of the North American monsoon)," but they say others "have become worse" in terms of the more basic "continental seasonal surface climate." And, "furthermore," they conclude, "the uncertainty in the future projections across models can also be of the same magnitude [as] the model spread for the historic period."