Abstract
Static variable resolution atmospheric grids have been shown to be useful in capturing extreme weather and for modeling regional climates in a less computationally expensive as compared to a global high-resolution model. A variable resolution grid over the Continental United States (CONUS) was chosen to test the physics to be incorporated into the ACME model at ACME’s target atmospheric resolution of 1/4-degrees. For the CONUS grid, the low-resolution area has a resolution of ne30, or 1-degree, with the high-resolution region being ne120, or 1/4-degree resolution. Three simulations are compared to better understand the global and CONUS climatologies. The first simulation is a 5-year pre-industrial simulation using the same tuning parameters as the ACME v0.1 AMIP with the CONUS grid. The second is an ensemble member of a global high-resolution simulation of ACME v0.1 AMIP. The third is a global low-resolution simulation again using the same tuning parameters as the ACME v0.1 AMIP. The magnitudes and spatial patterns of the convective and large-scale precipitation show the CONUS region has similar climatology as an ensemble member of the high-resolution simulation’s similar region. Improvements in the resolution of the topography appear to cause most of the similarities between the high-resolution simulation and the CONUS simulation.