The Joint Effort for Data assimilation Integration (JEDI) is an open-source, community-driven framework developed by the Joint Center for Satellite Data Assimilation (JCSDA) in collaboration with NOAA, Met Office, NASA, the U.S. Navy, the U.S. Air Force, and other partners. JEDI aims to unify data assimilation (DA) practices across Earth system components – including atmosphere, ocean, land, and atmospheric composition – by providing a modular, scalable, and model-agnostic infrastructure that supports both research and operational forecasting needs.

This special issue seeks to highlight advancements, applications, and evaluations of the JEDI framework in both research and operational settings. Topics of interest include, but are not limited to, the following:

• implementation of variational and ensemble-based DA techniques within JEDI;
• DA applications involving atmosphere, ocean, land, atmospheric composition, etc.;
• integration of novel observational data sources;
• observation processing under the JEDI framework;
• development of tools and workflows to facilitate JEDI research-to-operations (R2O) transitions.

Review process: all papers of this special issue underwent the regular interactive peer-review process of Geoscientific Model Development handled by members of the GMD editorial board.