Evaluating Variable Resolution-CESM for the North American Monsoon System

The North American Monsoon System (NAMS) region in southwestern US and northwestern Mexico is characterized by a strong peak of precipitation present from June to September. The ability of GCMs to simulate NAMS precipitation is limited by the coarse horizontal resolution typically used (~100 km), which is insufficient to resolve critical features and processes associated with the monsoon, including: the Gulf of California (average width: 150 km) and the interaction of the associated moisture surges with the complex topography of the region. In this study we evaluate the ability of Variable Resolution-CESM (VR-CESM), configured with a 25 km-resolution region over southwestern North America, to simulate various aspects of NAMS precipitation.