This PR follows Jongil's suggestion and aims to reduce the large convective reflectivity caused by saSAS adjustment in the first timestep during a warm start. The issue is likely related to the inconsistency when DA updates the moisture at t but not the moisture from the previous timestep (t-36s). The moisture from the previous timestep is needed for initializing sigmab (updraft area fraction) when calculating qadv (q advection or tendency term).
The PR forces qadv to zero in the first timestep when a namelist parameter sigmab_coldstart is set to .true. It also reduces the lower limit of sigmab from 0.01 to 0.0 in the first timestep.
Link the issues to be closed with this PR, whether in this repository, or in another repository.
(Remember, issues should always be created before starting work on a PR branch!)
fixes #
fixes noaa-emc/fv3atm/issues/
Testing
How were these changes tested?
What compilers / HPCs was it tested with?
Are the changes covered by regression tests? (If not, why? Do new tests need to be added?)
Have the ufs-weather-model regression test been run? On what platform?
Will the code updates change regression test baseline? If yes, why? Please show the baseline directory below.
Please commit the regression test log files in your ufs-weather-model branch
Dependencies
If testing this branch requires non-default branches in other repositories, list them.
Those branches should have matching names (ideally)
Do PRs in upstream repositories need to be merged first?
If so add the "waiting for other repos" label and list the upstream PRs
waiting on noaa-emc/nems/pull/
waiting on noaa-emc/fv3atm/pull/
Requirements before merging
[ ] All new code in this PR is tested by at least one unit test
[ ] All new code in this PR includes Doxygen documentation
[ ] All new code in this PR does not add new compilation warnings (check CI output)
Description
This PR follows Jongil's suggestion and aims to reduce the large convective reflectivity caused by saSAS adjustment in the first timestep during a warm start. The issue is likely related to the inconsistency when DA updates the moisture at t but not the moisture from the previous timestep (t-36s). The moisture from the previous timestep is needed for initializing sigmab (updraft area fraction) when calculating qadv (q advection or tendency term).
The PR forces qadv to zero in the first timestep when a namelist parameter sigmab_coldstart is set to .true. It also reduces the lower limit of sigmab from 0.01 to 0.0 in the first timestep.
dependent on ccpp-physics PR:
https://github.com/ufs-community/ccpp-physics/pull/225
Issue(s) addressed
Link the issues to be closed with this PR, whether in this repository, or in another repository. (Remember, issues should always be created before starting work on a PR branch!)
Testing
How were these changes tested?
What compilers / HPCs was it tested with?
Are the changes covered by regression tests? (If not, why? Do new tests need to be added?)
Have the ufs-weather-model regression test been run? On what platform?
Dependencies
If testing this branch requires non-default branches in other repositories, list them. Those branches should have matching names (ideally)
Do PRs in upstream repositories need to be merged first? If so add the "waiting for other repos" label and list the upstream PRs
Requirements before merging