...
After 50 years, this quantity is still increasing at a linear rate.
Remapping an existing initial condition
With the apparent slow spin-up of the land model from a cold-start, even for an I-case, it makes sense to try to get a jump-start on spin-up by starting with an existing spun-up initial condition, and remapping to our target grid, and then performing a (hopefully shorter) additional adjustment/spin-up period on the new grid. ELM provides a tool for remapping initial conditions, as it is apparently not as straightforward a process as remapping data for the other components, I think because the land model restart files describe only a subset of the grid and in some specialized format (someone who knows more about this should comment here, I’m still surprised we need a special tool to do this). That remap tool is in:
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components/elm/tools/clm4_5/interpinic |
Other than some simple Makefile and source code fixes to build on cori (upcoming in a PR), the tool is easy to build and run. The following was sufficient to create a remapped initial condition from a 1000 year pre-industrial control simulation at ne30:
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#!/bin/bash
# Source our configuration file to set paths/variables
source config.sh
# First, build initial condition interpolator
rm env_mach_specific.xml
${e3sm_root}/cime/tools/configure --machine ${machine} || exit 1
source .env_mach_specific.sh || exit 1
cd ${e3sm_root}/components/elm/tools/clm4_5/interpinic/src
USER_FC=${fortran_compiler} LIB_NETCDF="`nc-config --libdir`" INC_NETCDF="`nf-config --includedir`" make VERBOSE=2
# Next, run using a well-spun-up initial condition
source_inic_file=/global/cscratch1/sd/bhillma/e3sm/cases/v2rc3.piControl.ne30pg2_EC30to60E2r2/archive/rest/1001-01-01-00000/20210528.v2rc3c.piControl.ne30pg2_EC30to60E2r2.chrysalis.elm.r.1001-01-01-00000.nc
target_inic_file=~/codes/e3sm/cases/add-arcticx4v1-rrm.arcticx4v1pg2_oARRM60to10.ICRUELM.spinup1/run/add-arcticx4v1-rrm.arcticx4v1pg2_oARRM60to10.ICRUELM.spinup1.elm.r.0091-01-01-00000.nc
output_inic_file=${output_root}/${lnd_grid_name}.elm.r.1001-01-01-00000.nc
cp ${target_inic_file} ${output_inic_file}
cd ${e3sm_root}/components/elm/tools/clm4_5/interpinic
./interpinic -i ${source_inic_file} -o ${output_inic_file} |