PSL develops or helps develop several reanalysis products that use and improve the UFS.
PSL, in collaboration with the National Weather Service, NASA, and artificial intelligence startup partner Brightband, develops and maintains the NOAA-NASA Joint Archive (NNJA).
NNJA is an experimental effort to provide a unified, curated dataset of Earth system observations from 1979 to the present, hosted on AWS S3. Designed to support Earth System reanalysis research, the archive enables consistent comparison across reanalysis efforts by minimizing variability in input observations. The dataset includes ocean, land, ice, and atmospheric data in formats such as BUFR, IODA, and NetCDF, along with quality control tools and metadata like observation errors and black/white lists. Future developments aim to expand data coverage to near real-time, enhance usability through APIs, and provide robust diagnostics, offering broad value to the Earth system science community.
PSL has developed a new “replay” dataset to support improvements to the Global Ensemble Forecast System (GEFSv13) and Global Forecast System (GFSv17). It is a modern reanalysis-like dataset for coupled atmosphere, ocean, ice, land, and waves.
By nudging a coupled model toward ERA5 and ORAS5 reanalysis data, this dataset enhances the accuracy of retrospective forecasts and supports machine learning applications. It provides initial conditions for the UFS model and AI training data from 1979 to 2025. The effort aims to improve medium-range global weather predictions and reduce model biases through innovative data assimilation techniques.
Visit the UFS Replay project page
The 20th Century Reanalysis is a flagship atmospheric reanalysis that uses advanced data assimilation and surface pressure observations to create a comprehensive 4D weather dataset spanning 1806 to 2015. This allows researchers to analyze modern atmospheric patterns within a deep historical context. This was a collaborative project between NOAA, the Department of Energy, and the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder.
Visit the 20th Century Reanalysis project page
PSL is using the Global Forecast System (GFSv17) to generate historic Earth system reconstructions that span from 1979 to the present. These reconstructions provide a consistent, gap-filled estimate of past atmospheric, oceanic, ice, and land conditions, simulating the atmosphere as accurately as possible using modern data assimilation techniques and today’s best forecast models. While the initial customer for this reanalysis is the initialization of the Seasonal Forecast System, we are actively exploring how this effort could be expanded to provide high-quality, high-resolution model simulations for training of the AI models for Project EAGLE.