MUSICA Version 1 is a configuration of the CAM-chem global chemistry climate model. This model development takes advantage of the non-hydrostatic dynamical core MPAS (an unstructured grid mesh based on Veronoi meshes) which allows for regional refinement (RR). The MPAS dynamical core allows for simulations at convective permitting and urban grid scales (<5 km).
Testing of MUSICAv1 (CAM-MPAS with full chemistry) is being conducted using a 60 km to 3 km grid mesh with regional refinement over northeast India / southern China where Asian monsoon convection frequently occurs. The test simulations are being performed in the context of the Asian Summer Monsoon Chemical and Climate Impact Project (ACCLIP) field campaign whose goal is to investigate the impacts of Asian gas and aerosol emissions on global chemistry and climate via the linkage of Asian Summer Monsoon (ASM) convection and associated large-scale dynamics.
Shown is the CAM-MPAS 60 - 3 km grid mesh for the ACCLIP simulations. Circles denote grid spacing of the grid mesh with the inner circle set to 4 km, the outer circle set to 56 km, and increments of 4 km. The mesh is centered at 25 N, 100 E to place much of the convection in the 3 km grid region. The center panel shows carbon monoxide at 14 km altitude from the CAM-MPAS with chemistry simulation has the same magnitude and transport patterns as the WACCM uniform grid simulation (right panel). These results show that CAM-MPAS with chemistry is viable, yet the model configuration is still being tested and evaluated. We hope to provide more updates in late 2023.