Progress Towards a Weakly-Coupled JEDI-Based Global Data Assimilation System

As part of the transition to the Unified Forecast System (UFS), progress is being made at the National Centers for Environmental Prediction (NCEP) towards coupled Earth system global numerical weather prediction. Along with the shift to coupled modeling comes the need for coupled data assimilation for initialization of the Earth system model. For this, NCEP is developing a Unified Data Assimilation (UDA) system based on the Joint Effort for Data assimilation Integration (JEDI) framework to produce weakly coupled (atmosphere, ocean, sea-ice, land, and aerosols) analyses. The JEDI project is a joint effort between the Joint Center for Satellite Data Assimilation (JCSDA), groups from NOAA, NASA, the US Navy and Air Force, and the UK MetOffice. NCEP plans to replace the currently operational Gridpoint Statistical Interpolation (GSI) software with JEDI for all operational analyses. Here we present results from a UFS cycled system, with JEDI-based weakly-coupled DA for the ocean, sea-ice, land, and aerosols, and GSI-based atmospheric DA, and progress towards implementing this in the next major version of the Global Forecast System (GFS). In parallel, evaluation and development of JEDI-based atmospheric DA continues, and results comparing GSI and JEDI-based global atmospheric DA systems will be shown. Finally, the current state and path towards a fully JEDI-based global DA system will be outlined.