| Warning |
|---|
NERSC Directory Change Notice Due to project's name change at NERSC from 'ACME' to 'E3SM' and NERSC’s file system update, the directory ' |
...
In order to generate mapping files to do interpolation between a new atmosphere grid and the other component grids, we need to create a file that describes the atmosphere grid representation. The TempestRemap tool (https://github.com/ClimateGlobalChange/tempestremap) can be used to recreate the internal representation of the spectral element grids used in HOMME. The grid mesh file will be saved in an "exodus" type file (with a .g extension).
TempestRemap needs to can now be pulled in with NCO via conda, or can be built from source from the Github repository. This is straightforward on Cori and Edison. Note that a parallel version of netCDF should be used. This can be accomplished on cori/edison be executing module swap cray-netcdf cray-netcdf-hdf5parallel or by sourcing an env_mach_specific.sh from a working case on the target machine before building. Then,
...
E3SM V1
V1 uses topography on a GLL grid with a laplacing smoothing. The smoothing reduces the effective resolution of the topography from 2dx to 6.4dx. (effective resolution is determined by the first wavelength to be damped by 50% from the unsmoothed topography, computed via spherical harmonic spectra)
V1 only needs data on the GLL grid.
Tool chain: Topography generation for GLL grids Requires cube_to_target, homme_tool, and a SCRIP file for the grid.
V1 has poor treatment of topography and compensates in part with increased divergence damping.
E3SM V2
V2 needs topography on the GLL grid, and then a consistent topography on the PG2 grid (created with the same GLL->PG2 algorithm used internally)
V2 uses the same smoothing as V1: 50% damping of the 6.4dx wavelength.
Tool chain: Special Considerations for FV Physics Grids
V2 has improved topography treatment over V1. V2 configurations do not need to run with increased divergence damping.
E3SM V3
V3 needs topography on the GLL grid, and then a consistent topography on the PG2 grid (created with the same GLL->PG2 algorithm used internally)
V3 has improved pressure gradient and viscosity treatment over V2 and will be using a significantly rougher topography.
This tool chain has not been finalized yet.
...
Two options are now available to generate the atmosphere initial condition. The first method is document on the page: Generate atm initial condition from analysis data. The second method is documented here in the section Spinning up the atmosphere.
Option 1: Generate atm initial condition from analysis data
Option 2: Spinning up the atmosphere
...
land grid descriptor file in SCRIP format
ESMF_RegridWeightGen
geographic distribution for each land surface type along with grid descriptor files for each of those surface types
mkmapdata.sh (found in components/clm/tools/shared/mkmapdata/)
mksurfdata.pl (found in components/clm/tools/clm4_5/mksurfdata_map/)
...