Add variable DO_ENVAR_RADAR_REF_ONCE with brief description to RRFS CONUS config file

[AmandaBack-NOAA]

DESCRIPTION OF CHANGES:

Add a line
DO_ENVAR_RADAR_REF_ONCE="TRUE" (its current default) to the RRFS_CONUS_3km config.sh with a comment explaining what it is for, so people building retros know how to turn SDL/VDL and hybrid radar ref task on and off

TESTS CONDUCTED:

Built and ran successfully with the variable set to both TRUE and FALSE

Machines/Platforms:

• WCOSS2
  • Cactus/Dogwood
  • Acorn
• RDHPCS
  • [ X] Hera
  • Jet
  • Orion
  • Hercules

Test cases:

• Engineering tests
  • Non-DA engineering test
  • DA engineering test
    • Retro
    • Ensemble
    • Parallel
• RRFS fire weather
• RRFS_A:
• RRFS_B:
• RTMA:
• Others:

ISSUE:

• Addresses the issue(s) mentioned in The variable name DO_ENVAR_RADAR_REF_ONCE does not hint at its use #222

[MatthewPyle-NOAA]

Looks good from my perspective, but if @hu5970 or @ShunLiu-NOAA could confirm from a DA perspective that would be great.

[ShunLiu-NOAA]

Looks good to me.

[shoyokota]

@AmandaBack-NOAA Originally I introduced DO_ENVAR_RADAR_REF_ONCE as the variable to be set indirectly depending on ngvarloc in ush/set_rrfs_config_SDL_VDL_MixEn.sh, so in my opinion, we don't necessarily need this modification. If it is not understandable, it may be good to add the comment in ush/set_rrfs_config_SDL_VDL_MixEn.sh.

[AmandaBack-NOAA]

@shoyokota Is it your position that someone who wants to run the RRFS workflow without SDL/VDL and have the hybrid radar reflectivity run as a separate task, should do so by going into set_rrfs_config_SDL_VDL_MixEn.sh and deleting or changing the values of ngvarloc and nsclgrp? If so, how is that communicated to the user? It seems esoteric to me.

[shoyokota]

@AmandaBack-NOAA Yes. We can set 2-scale SDL by setting nsclgrp=2 and 2-variable VDL by setting ngvarloc=2 in set_rrfs_config_SDL_VDL_MixEn.sh. If we don't want to apply neither SDL nor VDL, we set nsclgrp=1 and ngvarloc=1. In this implementation, DO_ENVAR_RADAR_REF_ONCE is set automatically in set_rrfs_config_SDL_VDL_MixEn.sh. This 2-variable VDL is only for simultaneous radar reflectivity DA, so I don't think we need to set DO_ENVAR_RADAR_REF_ONCE independently from ngvarloc.

To set nsclgrp and ngvarloc in set_rrfs_config_SDL_VDL_MixEn.sh is based on @hu5970's suggestion, so @hu5970 may also have some opinions, but if we should set them in config.sh, it may be good to move nsclgrp and ngvarloc to just before calling set_rrfs_config_SDL_VDL_MixEn.sh in config.sh.

[AmandaBack-NOAA]

@shoyokota @hu5970 I would be happy with a solution that sets nsclgrp and ngvarloc in config.sh, if accompanied by a comment in config.sh explaining how to use them, both for SDL/VDL and to turn off SDL/VDL.

[chunhuazhou]

@AmandaBack-NOAA My understanding is that if the user wants to run the EnVar analysis with SDLVDL, simply add . set_rrfs_config_SDL_VDL_MixEn.sh after . set_rrfs_config_general.sh in config.sh for the deterministic run (for example, config.sh.RRFS_CONUS_3km ). It will enable SDLVDL. Without this line (. set_rrfs_config_SDL_VDL_MixEn.sh) in config.sh, SDLVDL is off by default.
And as @shoyokota mentioned above, when SDLVDL is enabled, we have DO_ENVAR_RADAR_REF_ONCE="TRUE" as in line 27 in set_rrfs_config_SDL_VDL_MixEn.sh

[AmandaBack-NOAA]

@chunhuazhou set_rrfs_config_SDL_VDL_MixEn.sh does not need to be added to config.sh for RRFS_CONUS_3km. It is there by default in the sample config and has been since before the GSL retros switched to using SDL/VDL.
If the intended use is to comment out or delete set_rrfs_config_SDL_VDL_MixEn.sh to run without SDL/VDL, I would be fine with a line indicating that in the RRFS_CONUS_3km sample config.
My solution was to add the line DO_ENVAR_RADAR_REF_ONCE="TRUE" to the config so that by default the setting doesn't change, but it's there if someone wants to change it. Either is fine with me. But the method to toggle SDL/VDL on and off does not need to be obscure, as far as I know.

[chunhuazhou]

Setting this to TRUE doesn't turn on SDLVDL, but to assimilate radar ref with other obs when SDLVDL is on

[AmandaBack-NOAA]

Good point @chunhuazhou. Actually I forgot I made this yesterday and made other changes in my fork today, so I need to close this anyway. I hope someone else will find a solution to issue #222 because it still stands.