UFS with GSI

Submitted by steven.fletcher on Mon, 04/19/2021 - 13:10

I am building an osse and i am working with the UFS (FV3) model and am looking for information about interfacing to the output from the UFS and GSI.

Specifically 1) How do we load the UFS tile output into GSI for the back ground run as well as into the format for the CRTM?

2) What output do we use to be able to reinitiate UFS?




In reply to by wmayfield

Hi Will

Thanks for this, unfortunately it is no regional but global.  The output is on the Gaussian grid for each tile but i am not sure if it is possible to output the UFS to be one Gaussian grid file and then it is a case of matching the resolutions in the GSI.  Is there a Gaussian grid reader in the GSI?



Hi Steve,


GSI reads a gaussian grid in either the nemsio format or the compressed netcdf format (single file) that is in use since the upgrade to GFSv16 last month, and which now appears on nomads, etc. There is a if_ncio flag similar to the if_nemsio flag that propagate these settings to the GSI namelist. Chgres can take these formats to provide the fv3 input files. As for going from the fv3 tiles to these formats to be ingested in GSI, there are utilities in the global workflow (https://github.com/NOAA-EMC/global-workflow  check ush and other directories) that handle the re-gridding and conversion. They are set up to be used as part of that workflow, though, so it may take some adaptation if your goal is to do this in a stand-alone fashion---I haven't done that before but if you have CIRA colleagues at GSL to ask they may know if anyone may be doing so.