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Welcome
The Unified Forecast System (UFS) is a community-based, coupled, comprehensive Earth modeling system. NOAA’s operational model suite for numerical weather prediction (NWP) is quickly transitioning to the UFS from a number of different modeling systems. The UFS enables research, development, and contribution opportunities within the broader Weather Enterprise (including government, industry, and academia). For more information about the UFS, visit the UFS Portal.
Description
The UFS includes multiple applications that support different forecast durations and spatial domains. The offline UFS Land Data Assimilation (DA) System is based on the Noah Multi-Physics (Noah-MP) land surface model (LSM) used in the UFS Weather Model (WM). The Noah-MP source code is available as an external UFS component and as a LSM option in the Common Community Physics Package Common Community Physics Package (CCPP). The Land DA framework uses the Joint Effort for Data assimilation Integration (JEDI) system, which includes the Object-Oriented Prediction System (OOPS) for the data assimilation algorithm, the Interface for Observation Data Access (IODA) for observation formatting and processing, and the Unified Forward Operator (UFO) for comparing model forecasts and observations.
In both the standalone, uncoupled configuration and in the coupled UFS component structure, near-surface atmospheric forcing data is required as input forcing. The Noah MP LSM simulates soil moisture (both liquid and frozen), soil temperature, skin temperature, snow depth, snow water equivalent (SWE), snow density, canopy water content, and the energy flux and water flux terms of the surface energy balance and surface water balance. Its data assimilation framework applies the Local Ensemble Transform Kalman Filter-Optimal Interpolation (LETKF-OI) algorithm to combine the state-dependent background error derived from an ensemble forecast with the observations and their corresponding uncertainties to produce an analysis ensemble (Hunt et al., 2007).
For any publications based on work with the UFS Offline Land Data Assimilation System, please include a citation to the DOI below:
UFS Development Team. (2023, Dec. 11). Unified Forecast System (UFS) Land Data Assimilation (DA) System (Version v1.2.0). Zenodo. https://doi.org/10.5281/zenodo.7675721
Getting Started
Before running the Land DA System, users should determine which of the four levels of support is applicable to their system. Generally, Level 1 & 2 systems are restricted to those with access through NOAA and its affiliates. These systems are named (e.g., Hera, Orion). However, most users can take advantage of containers to operate Land DA on any system.
The Land DA workflow described in the v1.2.0 User’s Guide is an excellent place for new users on Level 1 systems to begin. It provides details on how to clone the Land DA System, build it, and run a forecast on Hera or Orion. The Containerized Land DA Workflow chapter is the best place for users on other systems to start. It walks users through running the Land DA workflow via Singularity container on non-Level 1 systems.
Documentation & User Support
The Land DA User’s Guide has the most comprehensive information on the Land DA System. Users may need different versions of the User’s Guide depending on their goals:
Version
Description
Documentation for the head of the develop branch. This may have gaps and errors.
Documentation for the most recent release (v1.2.0).
Documentation for the v1.1.0 release.
Users can also get expert help through the GitHub Discussions Q&A.
Developer Support
The Land DA Developer Information page provides information on the Land DA hierarchical repository structure, developer support, and testing.
Releases
The latest release of the Land DA System is v1.2.0. See the Releases page for more information on current and past releases.
Release Date: 12/11/2023
Release Description: The Land Data Assimilation (DA) System combines the Noah-MP land surface model with data assimilation capabilities into a user-friendly workflow. The Land DA workflow code base is charting a path forward to unify the Noah-MP forecast model with the UFS Weather Model (WM). Updates for this release include:
- Integration of the UFS Noah-MP land component into the Land DA System for use as an alternative to the Common Community Physics Package (CCPP) Noah-MP LSM land driver. The coupling layer of the land component is developed using the Earth System Modeling Framework (ESMF) and the National Unified Operational Prediction Capability (NUOPC) interoperability layer.
- Updates to model forcing options for use of the UFS land component
- Provided a new analysis option in the cubed-sphere native grid using GSWP3 forcing
- Established global land grid-point consistency with the head of the UFS WM baseline test cases
- Added a new sample configuration file (settings_DA_cycle_gswp3)
- Included an additional ECMWF ERA5 reanalysis forcing option in the existing vector-to-tile conversion analysis process
- CTest suite upgrades—the ERA5 CTests now test the operability of seven major components of Land DA: vector2tile, create_ens, letkfoi_snowda, apply_jediincr, tile2vector, land_driver, and ufs_datm_land
- Upgrade of the JEDI DA system to JEDI Skylab v4.0
- Updates to sample datasets for the release (see the Land DA data bucket)
- Singularity container (ubuntu20.04-intel-landda-release-public-v1.2.0.img) updates to support the changes described above
- Documentation updates to reflect the changes for this release
Known Issues:
- For the GSWP3 forcing option, an artificial GHCN snow depth observation file is provided for a single-cycle analysis test for 2000-01-03. The GHCN observation database will be extended in the near future.
Documentation:
Release Date: 05/25/2023
Release Description: The Land Data Assimilation (DA) System combines the Noah-MP land surface model with data assimilation capabilities into a user-friendly workflow. The Land DA workflow code base is charting a path forward to unify the Noah-MP forecast model with the UFS Weather Model (WM). Updates for this release include the migration of the Land DA System to the ufs-community GitHub space, the addition of a UFS WM build option, modulefile updates to use the spack-stack Unified Environment on Level 1 systems, and DA upgrades to utilize JEDI’s Skylab v3.0 release of jedi-bundle.
Known Issues:
- The GitHub Actions workflow YAML for the Docker-based build and CTest was turned off due to the limited disk space provided in the GitHub Actions free runner.
Documentation:
Other Links
- The spack-stack repository contains the prerequisite software needed to run the Land DA System and other UFS software. This software is preinstalled on Level 1 systems (e.g., Hera, Orion). Users can view the spack-stack documentation to install it on other systems.
- JEDI Documentation (Skylab v4.0): The Land DA System uses JEDI code for DA. The documentation contains information about the JEDI code and how to work with it.
- Land DA System Data Bucket: Get downloadable data to run supported Land DA cases.
- NOAA EPIC Docker Hub: A repository of container images (including Land DA container images) that users can download. Land DA containers package the Land DA System together with all its software dependencies for an easier experience building and running Land DA.
- UFS Land DA System README.md file
Get Started with the Land DA System
Resources
Public Release Code
v1.2.0 (latest)
For Developers
Land DA System Repository Structure
Useful Links
spack-stack code and spack-stack documentation
JEDI code and JEDI documentation (Skylab v4.0)
Land Data Assimilation (DA) System
The Unified Forecast System (UFS) is a community-based, coupled, comprehensive Earth modeling system. It supports multiple applications covering different forecast durations and spatial domains. The offline UFS Land Data Assimilation (DA) System is based on the Noah Multi-Physics (Noah-MP) land surface model (LSM) used in the UFS Weather Model (WM). The Noah-MP source code is available as an external UFS component and as a LSM option in the Common Community Physics Package Common Community Physics Package (CCPP). The Land DA framework uses the Joint Effort for Data assimilation Integration (JEDI) system, which includes the Object-Oriented Prediction System (OOPS) for the data assimilation algorithm, the Interface for Observation Data Access (IODA) for observation formatting and processing, and the Unified Forward Operator (UFO) for comparing model forecasts and observations.
In both the standalone, uncoupled configuration and in the coupled UFS component structure, near-surface atmospheric forcing data is required as input forcing. The Noah MP LSM simulates soil moisture (both liquid and frozen), soil temperature, skin temperature, snow depth, snow water equivalent (SWE), snow density, canopy water content, and the energy flux and water flux terms of the surface energy balance and surface water balance. Its data assimilation framework applies the Local Ensemble Transform Kalman Filter-Optimal Interpolation (LETKF-OI) algorithm to combine the state-dependent background error derived from an ensemble forecast with the observations and their corresponding uncertainties to produce an analysis ensemble (Hunt et al., 2007).
Links:
- The Land DA repository contains the source code for the Land DA System.
- User’s Guides can be found here:
- The Land DA Data Bucket contains data for use with the most recent release.
- For an introduction to the repository, see the Land DA wiki and the README.md file.
- The Land DA Docker Hub is a repository of Land DA System container images that users can download. These containers package the Land DA System together with all its software dependencies for an easier experience building and running Land DA.
- JEDI Documentation (Skylab v4.0): The Land DA System uses JEDI code for DA. This documentation contains information about the JEDI code and how to work with it.
- Spack-stack: The required libraries for building the Land DA System are available via spack-stack. Spack-stack provides a Spack-based method for building the software stack required for numerical weather prediction (NWP) tools. Users working on unsupported platforms will need to install the spack-stack on their system following the instructions in the spack-stack User’s Guide.
Citation:
UFS Development Team. (2023, December 11). Unified Forecast System (UFS) Land Data Assimilation (DA) System (Version v1.2.0). Zenodo. https://doi.org/10.5281/zenodo.7675721
Releases
Release Date: 2023-12-11
Release Description: The Land Data Assimilation (DA) System combines the Noah-MP land surface model with data assimilation capabilities into a user-friendly workflow. The Land DA workflow code base is charting a path forward to unify the Noah-MP forecast model with the UFS Weather Model (WM). Updates for this release include:
- Integration of the UFS Noah-MP land component into the Land DA System for use as an alternative to the Common Community Physics Package (CCPP) Noah-MP LSM land driver. The coupling layer of the land component is developed using the Earth System Modeling Framework (ESMF) and the National Unified Operational Prediction Capability (NUOPC) interoperability layer.
- Updates to model forcing options for use of the UFS land component
- Provided a new analysis option in the cubed-sphere native grid using GSWP3 forcing
- Established global land grid-point consistency with the head of the UFS WM baseline test cases
- Added a new sample configuration file (settings_DA_cycle_gswp3)
- Included an additional ECMWF ERA5 reanalysis forcing option in the existing vector-to-tile conversion analysis process
- CTest suite upgrades—the ERA5 CTests now test the operability of seven major components of Land DA: vector2tile, create_ens, letkfoi_snowda, apply_jediincr, tile2vector, land_driver, and ufs_datm_land.
- Upgrade of the JEDI DA system to JEDI Skylab v4.0
- Updates to sample datasets for the release (see the Land DA data bucket)
- Singularity container (ubuntu20.04-intel-landda-release-public-v1.2.0.img) updates to support the changes described above
- Documentation updates to reflect the changes for this release
Known Issues:
- For the GSWP3 forcing option, an artificial GHCN snow depth observation file is provided for a single-cycle analysis test for 2000-01-03. The GHCN observation database will be extended in the near future.
Documentation:
Release Date: 2023-05-25
Release Description: The Land Data Assimilation (DA) System combines the Noah-MP land surface model with data assimilation capabilities into a user-friendly workflow. The Land DA workflow code base is charting a path forward to unify the Noah-MP forecast model with the UFS Weather Model (WM). Updates for this release include the migration of the Land DA System to the ufs-community GitHub space, the addition of a UFS WM build option, modulefile updates to use the spack-stack Unified Environment on Level 1 systems, and DA upgrades to utilize JEDI’s Skylab v3.0 release of the jedi-bundle.
Known Issues:
- The Git Actions workflow yaml for the Docker-based build and CTest was turned off due to the limited disk space provided in the Git Actions free runner.
Documentation:
Release Date: 2023-03-06
Release Description: The Land DA System v1.0.0 combines the Noah-MP land surface model with data assimilation capabilities into a user-friendly workflow. The system is documented within the User’s Guide and supported through GitHub Discussions.
Documentation:
Land Data Assimilation (DA) System User’s Guide
User Support
For Land DA topics, users should direct their questions to the land-DA_workflow GitHub Discussions page. Begin a new discussion by selecting “New Discussion” in the Q&A category.
For frequently asked questions about the UFS and associated applications, models, and components, users can refer to EPIC’s Technical FAQs page.
