Run directory updates to default GCHP to c90 resolution

[mcdon1718-h]

Name and Institution (Required)

Name: Helena McDonald
Institution: Harvard University

Describe the update

Changes to setCommonRunSettings.template.sh and createRunDir.sh to default resolution to c90 for all simulations - removing separate logic for GEOS-IT. Additional notes directing users to the documentation and to think critically about their necessary run resolution.

Expected changes

No diff to chemistry.

Related Github Issue

• See Changing default model resolution from C24 to C90 GCHP#555

[yantosca]

Thanks for this @mcdon1718-h. It looks good to me except that we also need to add a sentence to CHANGELOG.md. I'll also wait for @lizziel's review before merging.

[lizziel]

See my comments. As Bob said, we also need an update in the changelog that the default grid resolution in GCHP run directories is changing from low resolution c24 or c30 to recommended resolution c90.

[lizziel]

I think we don't need this comment since the change is in the github history and will be in the changelog for the 14.8.0 changes.

[lizziel]

I think we can consolidate this section into distinct notes, combining the existing NOTE into it and highlighting the recommended C90 resolution. I took out the 14.8.0 reference and the warning about how C90 is now the default since it is in the changelog and the version summary. All settings in this file are supposed to be checked and edited before running.

# IMPORTANT NOTES:
#
# (1) C90 is the recommended minimum resolution for most scientific applications, 
# as the representation of transport processes begins to degrade below this threshold. 
# Lower resolutions of c24, c30, and c48 are recommended primarily for testing and 
# debugging purposes. See
# https://gchp.readthedocs.io/en/latest/supplement/horizontal-grids.html
# for more information about available grids.
#
# (2) Higher resolution results in increased computation cost and longer run times.
# Think carefully about your specific requirements before submitting new jobs. If doing
# your first GCHP run on a new system, we recommend using c24 with few cores.
#
# (3) If using mass flux inputs then grid resolution must be evenly divisible by input 
# mass flux resolution, or vice versa. Acceptable resolutions for GEOS-IT when using 
# mass fluxes are therefore in set [10,30,90,180,360,540,720,etc]