GCM Prototypes - UFS R2O
The Unified Forecast System (UFS) Global Coupled Model (GCM) Prototypes 5 through 8 (p5-p8) are the four most recent experimental versions of the UFS Global Coupled Model. The code for each version is frozen and available on GitHub (p5, p6, p7, p8). These experimental versions represent a significant intermediate stage in the ongoing development of the next release of the UFS medium-range weather (MRW) and seasonal to sub-seasonal (S2S) applications. More details of the model components and configuration are provided below. (Click each description to expand)
Model and data details
The UFS GCM is a coupled atmosphere-ocean-sea ice-waves model. All components are coupled using the National Unified Operational Prediction Capability (NUOPC) layer of the Earth System Modeling Framework (ESMF). The UFS coupled system is being developed based on the Global Forecast System (GFS) that is being used operationally for the medium range weather application. More details of the current operational GFS version can be found in the EMC Model Evaluation Group’s briefings.
Please see specifications of the UFS coupled prototype components in the below table. For more details on the prototypes’ evaluation, please see UFS S2S All-Hands presentations here.
| Atmosphere |
GFDL's Finite Volume Cubed-Sphere dynamical core (FV3) horizontal resolution c384 (~25km), 64 vertical levels (p5) or 127 vertical levels (p6, p7, p8) |
| Ocean | GFDL MOM6, Hybrid-coordinates with tripolar grid, 0.25 degree global resolution. 75 hybrid levels, OM4 Set up [Adcroft, 2019] |
| Sea Ice |
Los Alamos Sea Ice Model, version 6 (CICE6). Same grid as the ocean model. 5 thickness categories. No Mushy thermodynamics in p5 and p6; Mushy thermodynamics was turned on in p7 and p8. |
| Atmospheric Model Physics |
p5: GFSv15.2 Physics
p7: Modified GFSv16 Physics Modified GFSv16 Physics includes the following additions and updates: p8: Candidate GFSv17 Physics Candidate GFSv17 Physics includes the following additions and updates: |
| Waves | WAVEWATCH III wave model at 0.5 degree regular grid. Provides feedback to the atmosphere and ocean. ST4 Physics [Ardhuin, 2010]. |
|
Aerosols (p8 only) |
GOCART (Chin et al., 2003) model at the atmospheric model resolution. Does not provide feedback to other components. Uses FENGSHA (Dong et al., 2016) dust scheme. Predicts tropospheric mixing ratios of major aerosol species (dust, sea salt, black carbon, organic carbon, sulfur dioxide, sulfate, dimethylsulfide, methanesulfonic acid, nitrates, ammonia, ammonium). |
Forecast Details
|
Reforcast period |
Forecast lead | Frequency of initialization | Initial conditions (data) | Ensembles |
|
|
|
1st and 15th of each month, 168 forecasts in total. |
Ocn: 3Dvar CPC For p5 and p6: For p7: For p8: |
Control Run Only |
Data format, variables for Atmospheric Component
Output Interval: 6-hourly
Grid Resolution: C384 converted to regular 1536x768
File Format: grib2
| Directory | Contents* |
| prgb2 |
Atmospheric temperature, humidity, zonal, meridional and vertical velocity, vorticity, geopotential height, mixing ratios, at mandatory pressure levels |
| pgrb2b | Atmospheric temperature, humidity, zonal, meridional and vertical velocity, vorticity, geopotential height, mixing ratios, at additional levels |
| sflux |
Radiation, heat and momentum fluxes |
*List of key variables, files contain a number of other fields.
Data format, variables for Ocean Component
Output Interval: 6-hourly (+Daily)
Grid Resolution: Tripolar, primarily at ¼ degree 1440x1080
File Format: netcdf
| Directory | Contents* |
| ocn_2D |
Sea surface height, salinity, temperature, velocity, fluxes |
| ocn_3D | 3-D fields of potential temperature, salinity, velocity |
| ocn_daily | SST, fluxes+ |
*List of key variables, files contain a number of other fields.
Data format, variables for Sea Ice Component
Output Interval: 6-hourly
Grid Resolution: Tripolar, primarily at ¼ degree 1440x1080
File Format: netcdf
| Directory | Contents* |
| ice | Ice area, thickness, velocity, stress, melt, growth, snow cover, freeze/melt onset Fluxes, temperatures, precipitation rates |
*List of key variables, files contain a number of other fields.
Data format, variables for Aerosol Component (p8 only)
Output Interval: 6-hourly
Grid Resolution: Regular ½ degree 720x321
File Format: nc4
| Directory | Contents* |
| chem | Aerosol optical depths at 470 nm: total, and by species |
*List of key variables, files contain a number of other fields.
In collaboration with the NOAA Open Data Dissemination (NODD, formerly NOAA Big Data) Program, the GCM p5-8 data is now available on the AWS here.
Researchers interested in the global prediction and model development are invited to evaluate the UFS Global Coupled Model Prototype data. Analysis of the data may include, but is not limited to, process-based evaluations, diagnostic measures that reveal coupled feedback processes and forecast skill estimations. Interested researchers may also volunteer to communicate their findings to the UFS-R2O project team, see contact information below. Note that this is a voluntary opportunity to collaborate. No funding is associated with this announcement at this time.
Requirements for Data usage
Users of UFS GCM Prototype data are requested to acknowledge the data source and sponsoring agencies that support the UFS-R2O project. In publications, it is recommended to include a text similar to the one below, in the acknowledgement section.
“The Unified Forecast System (UFS) Global Coupled Model (GCM) experimental prototypes data used in this study are produced at the National Weather Service Environmental Modeling Center, NWS/NCEP/Environmental Modeling center (EMC), and made available through the UFS Research to Operations (UFS-R2O) project that is sponsored by the National Weather Service (NWS) Office of Science and Technology Integration (OSTI) Modeling Program Division and the National Oceanic and Atmospheric Administration (NOAA) Oceanic and Atmospheric Research (OAR) Weather Program Office (WPO).”
Disclaimer
Users are cautioned the data was made with an intermediate version of the UFS that is still under vigorous development and evaluation, see NWS disclaimer for additional details.
Acknowledgment
Special thanks to the UFS-R2O Coupled System team at NWS/NCEP/EMC, led by Avichal Mehra and Fanglin Yang, for producing and providing the GCM data along with the information on this page.
For additional information about the GCM prototype data set, please contact the UFS-R2O project engineers at ufs-r2o-engineers@noaa.gov
For inquiries on how to engage with the UFS-R2O project in general, please contact the project leads at ufs-r2o-leads@noaa.gov