Add GCHP ctmEnv-only simulation option

[lizziel]

Name and Institution (Required)

Name: Lizzie Lundgren
Institution: Harvard University

Describe the update

This update introduces a compile-time option for a new simulation that does not run GEOS-Chem or advection. The GCHPctmEnv gridded component, which is at the same hierarchical ESMF level as GEOS-Chem and FV3, is the only child gridded component of GCHP_GridComp that is run. The purpose of this is to experiment with producing 12 km lat-lon wind exports from c720 mass flux imports using MAPL.

The ctmEnv simulation option is enabled by building with -DMODEL_CTMENV=y. There is an accompanying update in the GEOS-Chem repository for the option to create a a run directory for the ctmEnv simulation.

Important notes:

• All of GCHP is compiled with the exception of code within #ifndef MODEL_CTMENV blocks.
• Dynamics is both compiled and initialized. This avoids code dependency issues.
• The simulation could be extended in the future to optionally include dynamics with a simple tracer.
• The simulation does not use restart files. This enables it to be extremely lightweight and fast when run at high resolutions.

This update will require concurrent merge of geoschem/geos-chem#2742.

Expected changes

This is a no diff update.

Reference(s)

None

Related Github Issue

• Add GCHP ctmEnv simulation run directory option geos-chem#2742

[lizziel]

fyi @sdeastham