Initial Conditions

GFS initial condition files over the time period of your experiment are required as input files.

We are using T1534 initial condition files from the GFS operational runs. They are archived in SIGIO format on the mass store.

Files are saved in tar files stored by date:

/NCEPPROD/hpssprod/runhistory/rhYYYY/YYYYMM/YYYYMMDD/com_gfs_prod_gfs.YYYYMMDD00.anl.tar

         where YYYY = 4 digit year of run date
               MM   = 2 digit month of run date
               DD   = 2 digit day of run date

The initial condition files we need are gfs.t00z.sanl and gfs.t00z.sfcanl. To extract these files from the tar file and rename them to the expected filenames, use the following commands:

htar xvf ${gfsfile} ./gfs.t00z.sanl ./gfs.t00z.sfcanl
mv gfs.t00z.sanl   gfnanl.gfs.${yyyymmddhh}
mv gfs.t00z.sfcanl sfnanl.gfs.${yyyymmddhh}

We are running NEMS-based GFS at T574 resolution, so will need to change the resolution and format of the initial condition files (from T1534 SIGIO to T574 NEMSIO.) The script to do this is run_chgres_nemsio.sh. This script expects the initial condition files in the directory input and will write the NEMSIO T574 files to the directory chgres_out.

sh run_chgres_nemsio.sh -c $CDATE -d gfs -j 574

This script is not yet in the repository. We copied our file from Kate Howard's directory on theia: /scratch4/NCEPDEV/global/save/Kate. Howard/scripts/run_chgres_nemsio. sh