These instructions are specifically for NCAR computers derecho and casper.

The following steps describe Instructions for creating a new grid and using it in a beta version of CESM3.  They make use of existing executables on the NCAR high-performance computer system, derecho and casperderecho or casper.  More general instructions for CESM2.2 are available in the step-by-step guide.

For instructions on connecting to derecho or casper see: https://ncar.github.io/CESM-Tutorial/notebooks/prereqs/prereqs_overview.html   

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Several types of grid files need to be created.  These grids are described on the overview page.

Create SCRIP and LATLON grid files from EXODUS file

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Generate CESM input files on new grid

To keep with previous conventions for the structure of your new grid repository create directories inic, atmsrf and topo in your repository:

> cd $REPO
> mkdir inic
> mkdir atmsrf
> mkdir topo

The files created below are generally labeled with today's date.  Even if you make files on different days, all the files in one repository should have the same date (YYMMDD).

Regrid CAM IC file

The resulting file is assigned to ncdata in user_nl_cam.

> cd $REPO/inic

> cp /glade/work/emmons/tutorial_Nanjing/VRM_tools/gen_CAMncdata/TEMPLATES/interpic_script_TEMPLATE.sh interpic_script_Nanjing.sh

> vi interpic_script_Nanjing.sh

Edit the script to point to your grid files.

# USER CHANGES
VRdate="YYMMDD"
VRgridName="ne0np4.NAME.ne30xR"
VRgridLabel="NAME_RESOL"
VRrepoPath="your_repo_path"
# end of USER CHANGES

On casper:

> module load nco

> module load ncl

> qcmd -- 'sh interpic_script_Nanjing.sh > log_Nanjing'

Check there are no errors in the log file. This should have created an ic file with the dimensions of your new grid: cami-mam4_0000-01-01_ne0np4.Nanjing.ne30x8_L32_c240809.nc

Regrid 'atmsrf' file

The resulting file is assigned to drydep_srf_file in user_nl_cam.

Copy the template script to your working directory and edit for your grid.

> cp /glade/work/emmons/tutorial_Nanjing/VRM_tools/gen_atmsrf/TEMPLATES/gen_atmsrf_TEMPLATE.ncl gen_atmsrf_Nanjing.ncl

> vi gen_atmsrf_Nanjing.ncl

> qcmd -- 'ncl gen_atmsrf_GEMS01_ne30x8.ncl > log_GEMS01_ne30x8'

This writes atmsrf_(new_grid_name)_(date).nc

Create Topography file

The resulting file is assigned to bnd_topo in user_nl_cam.

Set up CESM3 with new grid

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