Attribution of Extremes in Regional North American Precipitation Using an RCM Large Ensemble

Understanding the influence of anthropogenic climate change on precipitation extremes will contribute to knowledge of event mechanisms and help with understanding the future evolution of extreme precipitation events. Previous analyses have detected an anthropogenic signal in hemispheric or continental precipitation extremes, but model limitations and the large signal-to-noise ratios found at smaller scales have often inhibited attribution at a regional level. Employing a unique dataset consisting of a large (50-member) ensemble of regional climate model simulations, we demonstrate the utility of this higher-resolution ensemble in representing precipitation extremes compared to a coarser earth system model. We then revisit the question of detection and attribution of regional precipitation extremes over North America.