Add support for reading constituents through input names in MPAS dynamical core

[kuanchihwang]

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Originator(s)

kuanchihwang

Description (include the issue title, and the keyword ['closes', 'fixes', 'resolves'] followed by the issue number)

Currently, MPAS dynamical core in CAM-SIMA only attempts to read constituents through the standard names. This PR adds support for also attempting the input names defined in the CAM-SIMA registry. Following the design principles of MPAS dynamical core, CAM-SIMA does not directly participate in the reading of constituents. Instead, MPAS dynamical core handles the actual I/O with its internal infrastructure.

Additionally, the dyn_mpas_define_scalar subroutine in the MPAS subdriver has been refactored to improve readability and reduce cyclomatic complexity. Pointer safety has been enhanced in the MPAS subdriver.

Describe any changes made to the build system

None

Describe any changes made to the namelist

None

List any changes to the defaults for the input datasets (e.g., initial, boundary datasets)

None

List all files eliminated and why

None

List all files added and what they do

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List all existing files that have been modified, and describe the changes

M       src/data/registry.xml
  * Add "qv" to candidate input names for water vapor mixing ratio
M       src/dynamics/mpas/driver/dyn_mpas_subdriver.F90
  * Use more idiomatic syntax for reordering MPAS scalars
  * Simplify algorithm for determining MPAS scalar indexes
  * Add support for reading constituents through input aliases in MPAS subdriver
  * Enhance pointer safety in MPAS subdriver
M       src/dynamics/mpas/dyn_comp_impl.F90
  * Update CAM-SIMA to adopt new `define_scalar` API from MPAS subdriver

Regression tests

• derecho/aux_sima_gnu

Pass.

• derecho/aux_sima_intel

  SMS_Ln9.ne3pg3_ne3pg3_mg37.FKESSLER.derecho_intel.cam-outfrq_se_cslam_multitape (Overall: NLFAIL) details:
    FAIL SMS_Ln9.ne3pg3_ne3pg3_mg37.FKESSLER.derecho_intel.cam-outfrq_se_cslam_multitape NLCOMP

Known failing test.

• derecho/aux_sima_nvhpc

Pass.

[kuanchihwang]

@mgduda

You might be interested in some parts of this PR because it adds a new feature for CAM-SIMA that depends heavily on the internals of MPAS. Thanks for your time in advance!

Specifically, commit b086d37 dynamically constructs a new field called scalars_alias at run-time, with all of its derived type components pointing to those in the scalars field except for constituentnames. The scalars field has the standard names of constituents in its constituentnames character array, while the scalars_alias field has the input aliases of constituents in its constituentnames character array.

The idea is to let the MPAS I/O stream facilities (e.g., mpas_streamaddfield, mpas_readstream) handle the input aliases natively. When these facilities encounter the scalars_alias field, the resulting data array is actually reflected to the scalars field, which is then used by other parts of MPAS transparently.