Add docs: Creating sparse-grid mesh and surface files

[samsrabin]

Once again @swensosc has fixed sparse-grid issues.

He made a mesh file and surface dataset that work!

mesh: /glade/work/afoster/ABoVE/for_adrianna/ESMFmesh_ctsm_NWT_pts.nc
surface file: /glade/work/afoster/ABoVE/for_adrianna/surfdata_0.9x1.25_hist_2000_16pfts_c250502.nc

Here are instructions:

1) use create_esmf_mesh_sites.py to create a mesh including only desired site coordinates

2) create surface data file in tools/mksurfdata_esmf

./gen_mksurfdata_namelist --start-year 2000 --end-year 2000 --res 0.9x1.25 --model-mesh ESMFmesh_ctsm_NWT_pts.nc --model-mesh-nx 9 --model-mesh-ny 1

./gen_mksurfdata_jobscript_single --number-of-nodes 1 --tasks-per-node 9 --namelist-file surfdata_0.9x1.25_hist_2000_78pfts_c250502.namelist

3) use mesh with subset_datm_vector.py to create datm forcing files

With his script I also made a DATM mesh file that is working as well!

/glade/work/afoster/ABoVE/for_adrianna/ABoVE_nwt_datmclmforc.GSWP3.c2011.0.5x0.5.TPQWL.SCRIP.210520_ESMFmesh.NWT_pts.nc

Thank you @swensosc!

@ekluzek are still not sure why this set of files work and the case described above doesn't.

Originally posted by @adrifoster in #3099

[ijaguirre]

Hi
I'm wondering if the new Plumber 2 Surface files tool should be included here. I'm referring to the tool described at plumber2_surf_wrapper

The tool works following this approach. Key arguments can be the sites, whether to include crops, how to treat longitude, among others. I have used it many times, and I consider that it would be fantastic to have it described in detail in the documentation.

cd tools/site_and_regional
rm -rf subset_data_single_point
./plumber2_surf_wrapper
ls subset_data_single_point | wc -l