make HEMCO the default emissions module for all CAM configurations w/ emissions

[adamrher]

What is the feature/what would you like to discuss?

HEMCO is being brought in https://github.com/ESCOMP/CAM/pull/560 to at first, only work with a specific CAM-Chem configuration. We would like to deprecate the old emissions workflow (i.e., the srf_emis and ext_frc specifiers), and configure HEMCO to handle all CAM cases using emissions. This requires tracking down the source data for most of the emission files in namelist_defaults and use_cases in order to generate HEMCO config files for all emissions scenarios, and then deprecate all the existing emissions files in namelist_defaults and use cases, and verifying everything is working as it should. It should only change answers to round off level; it shouldn't change the climate.

Here's the current HEMCO config file used for CAM-Chem to give you a flavor of what these files look like:

/glade/p/cesmdata/inputdata/atm/cam/geoschem/emis/HEMCO_Config.CC.CEDS_AEIC19.c230523.rc

See issue #856

Is there anyone in particular you want to be part of this conversation?

@jimmielin

Will this change (regression test) answers?

Yes

Will you be implementing this enhancement yourself?

No