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The North American Regional Climate-Change Assessment Program
Kim, J., Waliser, D.E., Mattmann, C.A., Mearns, L.O., Goodale, C.E., Hart, A.F., Crichton, D.J., McGinnis, S., Lee, H., Loikith, P.C. and Boustani, M. 2013. Evaluation of the surface climatology over the conterminous United States in the North American regional climate change assessment program hindcast experiment using a regional climate model evaluation system. Journal of Climate 26: 5698-5715.

The authors write that "even with the expected increases in computer resources that will allow GCMs [Global Climate Models] to run at higher horizontal resolutions, RCMs [Regional Climate Models] will remain essential to the processes [needed] for regional climate projections, climate change impact assessments, and policy making for the foreseeable future." And this being the case ...

What was done
... Kim et al. go on to describe how "surface air temperature, precipitation and insolation over the conterminous United Stages [derived] from the North American Regional Climate Change Assessment Program (NARCCAP) regional climate model (RCM) hindcast study [were] evaluated using the Jet Propulsion Laboratory (JPL) Regional Climate Model Evaluation System (RCMES)," which makes comparisons between modeled data and surface- and satellite-based observational data.

What was learned
The eleven U.S. researchers report that (1) "the most noticeable systematic errors in the annual-mean surface air temperatures are the warm biases in the Great Plains and the cold bias in the Atlantic and Gulf of Mexico coasts," that (2) "for the winter, the most outstanding RCM errors include the warm bias in the Atlantic coast and Florida regions and cold bias in northern California and Arizona-western New Mexico," that (3) "the most notable common errors in simulating the annual precipitation [are] the wet bias in the mountainous northwestern United States and dry bias in the Gulf Coast region and the southern Great Plains," that (4) "in the summer, most RCMs underestimate precipitation in Southern California, Arizona, New Mexico, the Great Plains, and western Texas," while they "overestimate in all three coastal regions," that (5) "all RCMs show especially poor performance in simulating the summer monsoon rainfall in the Arizona-western new Mexico region," and that (6) "the model bias in surface insolation varies widely according to RCMs."

What it means
Once again, we note the fact that as complex and powerful as today's GCMs and RCMs are, they are still in their infancy when it comes to trying to not only replicate, but to accurately predict real-world climate, not only in the near-term, but far into the future. Clearly, the models' reach vastly exceeds their grasp.

Reviewed 13 November 2013