variable gravity

[WChen-NOAA]

Commit Queue Requirements:

• This PR addresses a relevant WM issue (if not, create an issue).
• All subcomponent pull requests (if any) have been reviewed by their code managers.
• Run the full Intel+GNU RT suite (compared to current baselines), preferably on Ursa (Derecho or Hercules are acceptable alternatives). Exceptions: documentation-only PRs, CI-only PRs, etc.
  • Commit log file w/full results from RT suite run (if applicable).
  • Commit 'test_changes.list' (unless file is empty).
• Fill out all sections of this template.

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Description:

Initial NOAA-GFDL/GFDL_atmos_cubed_sphere#394
The model uses the shallow atmosphere approximation with constant gravity.
This is problematic for a space weather model (WAM) where Ztop/r0 )~10%
The method to resolve this issue is to Implement a scaling factor wherever gravity is applied to account for variations with height:
g(r0/r)^2 while setting var_grav = .true. in the name list
The new gravity as grav_var(i,j,k)

Commit Message:

* UFSWM - 
  * UFSATM - 
    * atmos_cubed_sphere - 

Priority:

• Critical Bugfix: Reason
• High: Reason
• Normal

Git Tracking

UFSWM:

• Closes #

Sub component Pull Requests:

• AQM:
• CDEPS:
• CICE:
• CMEPS:
• CMakeModules:
• FV3:variable gravity NOAA-EMC/ufsatm#1018 (comment)
  • ccpp-physics:
  • atmos_cubed_sphere:Variable gravity  NOAA-GFDL/GFDL_atmos_cubed_sphere#395 (comment)
• GOCART:
• HYCOM:
• MOM6:
• NOAHMP:
• WW3:
• fire_behavior:
• stochastic_physics:
• None

UFSWM Blocking Dependencies:

• Blocked by #
• None

Documentation:

• Documentation update required.
  • Relevant updates are included with this PR.
  • A WM issue has been opened to track the need for a documentation update; a person responsible for submitting the update has been assigned to the issue (link issue).
• Documentation update NOT required.
  • Explanation:

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Changes

Regression Test Changes (Please commit test_changes.list):

• PR Adds New Tests/Baselines.
• PR Updates/Changes Baselines.
• No Baseline Changes.

Input data Changes:

• None.
• New input data.
• Updated input data.

Library Changes/Upgrades:

• Required
  • Library names w/versions:
  • Git Stack Issue (JCSDA/spack-stack#)
• No Updates

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Testing Log:

• RDHPCS
  • Hera
  • Orion
  • Hercules
  • GaeaC6
  • Derecho
  • Ursa
• WCOSS2
  • Dogwood/Cactus
  • Acorn
• CI
• opnReqTest (complete task if unnecessary)

[gspetro-NOAA]

@WChen-NOAA Could you fill out the PR template fully with information on baseline changes, input data, and so on? If you are still working on this PR and don't have the full details yet, that's fine, but I would just want to update the PR status appropriately in our tracker.

[WChen-NOAA]

@gspetro-NOAA Hi, Thank you for the suggestions. But this change has no baseline change and input data. Currently it works for upper atmosphere with whole atmosphere model (WAM). If for UFS-WM, the option needs to be set as false. And I will check the information again and fill out what I could do.

[gspetro-NOAA]

@WChen-NOAA When you have a chance, please finish filling out the PR template, especially the "commit message" section. This PR will probably be on hold until after the shutdown because reviewers for atmos_cubed_sphere likely cannot review until then, but once we can get the subcomponent PRs reviewed and the PR template completed, this PR will be ready to schedule.