CCSM

CCSM stands for the Community Climate System Model, a coupled climate model developed by the National Center for Atmospheric Research (NCAR) in the United States. It is designed to simulate interactions among the atmosphere, ocean, land, and sea ice to reproduce the Earth’s climate system over long timescales. The model is used for paleoclimate studies, historical simulations, and future climate projections under various greenhouse gas forcing scenarios.

The CCSM is a modular, coupled general circulation model. Its principal components typically include the Community Atmosphere Model (CAM), the Parallel Ocean Program (POP), the Community Land Model (CLM), and the Sea Ice model (CICE). These components are integrated to exchange energy, momentum, moisture, and other tracers, enabling interactive climate simulations. Over successive releases, CCSM versions expanded in physical realism, spatial resolution, and coupling strategies.

Historically, CCSM has been released in major iterations such as CCSM3 and CCSM4, each refining model physics, numerics, and user interfaces. In the early 2010s NCAR reoriented the project toward broader Earth system complexity, and the CCSM initiative became part of what is now known as the Community Earth System Model (CESM). The CESM lineage encompasses newer generations, such as CESM2, and continues to be actively developed and used in climate research.

CCSM/CESM is widely employed in climate research to explore sensitivity to forcings, project future climate states, and support assessments by scientific bodies and international programs. The model is distributed to the research community under open-source terms, facilitating collaborative development and evaluation.