Benjamin Johnson, UCAR

Abstract:

The Joint Center for Satellite Data Assimilation (JCSDA) Community Radiative Transfer Model (CRTM) is a cornerstone for a wide spectrum of meteorological applications. It offers fast, accurate forward simulations and Jacobians with respect to state variables for various sensors, directly supporting research and operations in data assimilation, satellite retrievals, satellite calibration and validation, new sensor prototyping and development, retrieval algorithms, and a broad range of Earth system modeling and satellite simulation.  
In this talk, I’ll detail recent advances in CRTM, including enhanced cloud and aerosol parameterizations critical for accurate representation of weather and climate processes, and updated sensor-simulation capabilities that strengthen atmospheric state estimates. On the technical side, I’ll show how current code modernization efforts—optimizing for high-performance computing and new hardware—make CRTM more maintainable and scalable for both research and operational workflows.  We’ve expanded support for the latest satellite sensors, optimized the code for modern HPC systems, and built an open-source community that rapidly translates research innovations into operational capabilities. By keeping the code streamlined and flexible, CRTM remains a production-grade framework that stays ahead of emerging needs of both research and operational communities.
Finally, I’ll touch on how the open-source nature and community-driven development process ensure CRTM remains flexible, transparent, and ready to integrate new ideas. By promoting collaboration among operational agencies, academic groups, and the broader research community, CRTM continues to evolve in ways that serve emerging scientific and technical needs.