Seasonally specific precipitation variability in southwestern North America over the past millennium

Co-Author: Julia Cole

Co-Author: Melissa Harrington

Co-Author: Jonathan Overpeck

Co-Author: Toby Ault

We will examine the Last Millennium runs for variability in both the cool-season westerly and the summer monsoon precipitation. We will examine the relative roles of different forcings in their influence on particular seasons. We aim to evaluate whether the different dynamical regimes that characterize different seasons respond differently to forcings and/or exhibit different statistics (e.g. frequency dependence, duration and amplitude of extremes; spatial coherence). We will also look at how SW precipitation in warm and cool seasons is connected in the models to other internal aspects of variability, e.g. the “global monsoon”, ENSO/PDO, AMO, and others. This model-based assessment complements new paleoclimate data under development from regional caves as well as existing published data from many sources. This project is a contribution to the EASM2 Project "Quantifying and Conveyng the Risk of Prolonged Drought in Coming Decades."