The Effect of Weighting on the NARCCAP Ensemble Mean

As part of the European ENSEMBLES regional climate modeling project, six performance-based weighting metrics were developed in an effort to define differential model contributions to an ensemble mean. In this study, we will examine the effect of those weighting metrics on the ensemble of regional climate model (RCM) simulations produced as a part of the North American Regional Climate Change Assessment Program (NARCCAP). We will assess the impact of these performance-based weights versus equal weighting on the representation of the mean climate produced by the NARCCAP ensemble in the baseline/current climate period over North America and chosen sub-regions. The impact of the differential weighting on the ensemble projection of temperature and precipitation will also be examined.