MUSICA and SIMA Progress

The Multiscale Infrastructure for Chemistry and Aerosols (MUSICA) is currently being developed to become an NCAR-led next generation community infrastructure for studying atmospheric composition and addressing frontier science questions. MUSICA is part of the NCAR-wide project called System for Integrated Modeling of the Atmosphere (SIMA). The unique aspect of MUSICA, compared to current chemistry transport models, is that it will be capable of simulating the globe to capture large-scale phenomena while still resolving chemistry and physics at local scales relevant to support impact assessment and decision-making. NCAR/ACOM is developing MUSICA in two ways, a regionally refined version of the CAM-chem global chemistry climate model called MUSICAv0 and a box model version of MUSICA called MusicBox that allows process modeling and testing of new code.   

MUSICAv0

The MUSICAv0 model, which utilizes the spectral element unstructured grid available in CAM, is an initial prototype of MUSICA. The configuration with regional refinement over the contiguous U.S. was released with CESM2.2 in Fall 2020 along with the emissions tools to provide emissions on unstructured grid meshes. Using this configuration, a community simulation was conducted for 2012-2013. The output of this community simulation was made publicly available as part of the SIMA version 1 release in November 2021. 

Starting in November 2021, NCAR/ACOM scientists have been hosting a MUSICA tutorial series that focuses on visualizing model output, learning to run MUSICAv0, and developing user-specific regionally-refined grid meshes with the spectral element grid.  Additional sessions of the tutorial series include learning the new evaluation and analysis tool MELODIES and the box model version of MUSICA. 

Recent MUSICA software engineering efforts include creating an abstract interface for coupling  aerosol packages to  CAM6 physics. This structure will facilitate porting new aerosol packages to MUSICAv0 and achieve design goals for MUSICA of flexibility and modularity in a way that is compliant with the Community Common Physics Package. 

With the advent of having the non-hydrostatic dynamical core from the MPAS model being placed in CESM/CAM, NCAR/ACOM is aiming to produce MUSICA V1 which will allow regionally-refined simulations to < 4 km for urban air quality, and local scale interactions of chemistry with meteorology, e.g. land-sea breezes and cloud processing. NCAR/ACOM is currently evaluating CAM-MPAS with the MOZART-TS1 chemical mechanism at coarse grid resolutions. 

MusicBox

Other recent software engineering efforts have focused on the development of the box model version of MUSICA, called MusicBox, which became available to the community in 2021. MusicBox can be utilized either in a command-line approach, which is good for conducting many simulations for research, or via a browser-based interface that allows users with little or no experience working with command-line tools to interactively  configure the full chemical system and environmental and chemical conditions, run simulations, and analyze results. The interactive browser-based interface is an on-going student-developed project and demonstrates the benefits of MUSICA software design standards for testing, run-time configurability, component application programming interfaces (APIs), and documentation.