Part 14: Setting Up Regional Simulations

Regional simulations work similarly to site-level simulations but cover many grid cells.

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Generate Regional Surface Data

Navigate to:

cd $VSC_SCRATCH/cesm/sources/ctsm-5.2.0/tools/site_and_regional

Run:

./subset_data region \
    --create-surface \
    --lat1 -25 \
    --lat2 25 \
    --lon1 1 \
    --lon2 45 \
    --overwrite \
    --verbose \
    --outdir $VSC_SCRATCH/cesm/sitedata/africa \
    --inputdata-dir $VSC_SCRATCH/cesm/inputdata

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Create the Mesh File

Load NCO:

module load NCO

Copy the SCRIP file:

cp $VSC_SCRATCH/cesm/sitedata/scrip.nc ./

Generate the mesh:

ncks --rgr infer --rgr scrip=scrip.nc \
<fsurdat_generated_in_previous_step> \
lnd_mesh.nc

Convert:

ESMF_Scrip2Unstruct scrip.nc lnd_mesh.nc 0

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Create a Regional Run Script

Start from:

create_clm-fates-africa.sh

Rename it for your region.

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Update the Script

Modify:

SITE
surface file
mesh file
STOP_N
REST_N

and any desired output variables.

Regional simulations are useful when:

A single site is too small
Continental-scale patterns are required
Spatially explicit vegetation dynamics are needed