Potential run-time mismatch between mpas_init config_met_prefix values

[maddenp-cu]

Current Behavior

The MPAS init_atmosphere program allows the prefix for intermediate initial-conditions input file to be set via the config_met_prefix key in the data_sources namelist. The UW mpas_init driver supports setting this key via mpas_init.namelist.update_values.data_sources.config_met_prefix in UW YAML. However, the driver does not consult this value and instead assumes that the prefix is FILE, so that the input files init_atmosphere looks for at run time are not the files that have been staged by the driver.

Expected Behavior

No mismatch between staged files and namelist setting. This might involve propagating the hardcoded FILE value to the namelist and warning the user that their setting is being overridden. Even better: giving users a supported way to control the prefix value.

This issue probably also exists with other namelist values that UW drivers set while giving users the illusion that they can control them via namelist update_values: blocks. config_start_time and config_stop_time in namelist nhyd_model in the mpas_init driver come to mind.

To Reproduce

Extract the attached data.tgz as /tmp/data, then run

uw mpas_init provisioned_rundir -c config.yaml --cycle 2025-05-08T00

using the attached config.yaml.txt as config.yaml. (The cycle value does not matter.)

Note that, in /tmp/run:

lrwxrwxrwx 1 maddenp maddenp  28 May  9 05:02 FILE:2025-05-08_00 -> /tmp/data/FILE:2025-05-08_00
lrwxrwxrwx 1 maddenp maddenp  28 May  9 05:02 FILE:2025-05-08_06 -> /tmp/data/FILE:2025-05-08_06

but in /tmp/run/namelist.init_atmosphere:

&data_sources
    config_fg_interval = 21600
    config_met_prefix = 'CUSTOM'
/

Note the mismatch between FILE and CUSTOM.

Current Version

$ uw --version
uw version 2.8.0 build 0

This version is not yet released.

data.tgz
config.yaml.txt