Strip nested directories when writing ${EXTRN_MDL_VAR_DEFNS_FN}.sh

[benkozi]

Expected behavior

${EXTRN_MDL_VAR_DEFNS_FN}.sh should not use the nested path definition that can be provided via EXTRN_MDL_FILES_ICS/LBCS.

Current behavior

An external model filename definition can use a nested directory structure. The nested structure causes problems in make_ics/lbcs. Only the filename is needed not the nested structure. retrieve_data.py writes the nested path to ${EXTRN_MDL_VAR_DEFNS_FN}.sh via exregional_get_extrn_mdl_files.sh.

Example nested definition:

task_get_extrn_ics:
  envvars:
...
    EXTRN_MDL_FILES_ICS:
      - "gfs.{yyyymmdd}/{hh}/atmos/gfs.t{hh}z.atmf{fcst_hr:03d}.nc"

Cannot overwrite the behavior via:

task_make_ics:
  envvars:
    EXTRN_MDL_FNS:
      - "gfs.t{hh}z.atmf{fcst_hr:03d}.nc"

Machines affected

all

Detailed Description of Fix (optional)

A couple options:

• Patch retrieve_data.py to only use the filename when writing ${EXTRN_MDL_VAR_DEFNS_FN}.sh. There is still unexpected behavior since EXTRN_MDL_FNS cannot be overridden.
• Patch make_ics/lbcs scripts to respect EXTRN_MDL_FNS.

I don't think there would be cascading issues if both patch approaches were implemented.

Output (optional)

From chgres:

 - OPEN AND READ:
 /gpfs/f6/bil-fire8/scratch/Benjamin.Koziol/sandbox/srw/benkozi/use-cases/expt_dirs/aqm_AQMNA13km_SpringAQ/2023040112/FV3GFS/for_LBCS//gfs.20230401/12/atmos/gfs.t12z.atmf006.nc
...
FATAL ERROR: opening file: No such file or directory

Note: /gpfs/f6/bil-fire8/scratch/Benjamin.Koziol/sandbox/srw/benkozi/use-cases/expt_dirs/aqm_AQMNA13km_SpringAQ/2023040112/FV3GFS/for_LBCS/gfs.t12z.atmf006.nc exists.