MPAS in CESM
The nonhydrostatic dynamical core in the atmospheric component of the Model for Prediction Across Scales (MPAS-Atmosphere) is currently being integrated as a dynamical core into CESM as part if the SIMA project. MPAS-A is being incorporated as an external component in CESM/CIME, and is being pulled directly from the MPAS development/release repository. The ability to explicit simulation of atmospheric convection within a full earth-system model is one of the drivers for this project within SIMA. Since its initial release in 2012, MPAS-Atmosphere has been applied in numerous studies where atmospheric convection is explicitly simulated, and its capabilities are similar to that of WRF-ARW in this regard.
MPAS-Atmosphere employs an unstructured spherical centroidal Voronoi mesh in its discretization, thus allowing for both uniform and variable-resolution configurations, and a smooth transition between regions of different mesh densities. MPAS-Atmosphere can also be configured as a regional model, and this capability will also be available within SIMA.
Status: The SIMA port of MPAS-Atmosphere is at the stage where idealized dry global test are complete (Jablonowski and Williamson baroclinic wave test, Held and Suarez test). Full moist-physics capabilities are being implemented and testing should begin shortly.
A significant part of the MPAS in SIMA project is to allow the use of WRF/MPAS physics within SIMA. This capability is being developed using the Common Community Physics Package (CCPP) as the mediator between the MPAS-Atmosphere dynamical core and WRF/MPAS atmospheric physics. CCPP interfaces to selected physical parameterizations have been developed, and both WRF-ARW and MPAS can utilize these physics. A CCPP interface to the MPAS-Atmosphere dynamical core is also being developed for use in the stand-alone MPAS release. Importantly, the CCPP is also being implemented into SIMA (i.e. CESM/CAM), and will provide a standard interface to all physics and dynamical cores.
Status: The design and implementation of the CCPP in SIMA CESM/CAM is underway. A number of WRF/MPAS physics components have been made CCPP compatible, and the CCPP implmentation for the MPAS-Atmosphere dynamical core is underway.