CCSMCESM

CCSMCESM refers to the family of coupled climate models developed by the Community Climate System Model project, which evolved into the Community Earth System Model (CESM). The CCSM lineage produced several generations of models and, around 2010, the project was rebranded as CESM to reflect the inclusion of interactive Earth system components such as carbon and other biogeochemical cycles. The CESM framework has since progressed through multiple major releases and configuration options that support a wide range of climate research.

The model architecture integrates key components that simulate the atmosphere, ocean, land surface, and sea ice, coupled through a central communications framework. Typical components include an atmosphere model (CAM or related versions), an ocean model (POP or MOM variants), a land surface model (CLM) and a sea ice model (CICE). CESM configurations may also incorporate carbon and nitrogen cycles and other biogeochemical processes, enabling interactive feedbacks between physical climate and ecosystem dynamics. Researchers can run fully coupled simulations or configure the model for individual components or idealized experiments, as well as participate in multi-model intercomparison efforts such as CMIP.

Development and usage: CESM is maintained by the National Center for Atmospheric Research (NCAR) in collaboration with international partners. It is released under open-source licenses for the scientific community. The model has been employed in a wide range of studies, including historical and future climate projections, CMIP simulation ensembles, attribution analyses, and paleoclimate reconstructions. Ongoing development focuses on improving resolution, physics, and ecosystem representations, while maintaining a modular, community-driven workflow.