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homme_tool is an executable in ${homme_build}/src/tool/homme_tool produced in a standard configuration and build of standalone homme.
The second tool chain provides the best-quality GLL-physgrid file. It has five steps, illustrated for the case of ne30pg2:
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USGS-gtopo30_ne30np4pg2_16xdel2.nc is the final GLL-physgrid topography file.
The second tool chain can be modified if you have a GLL PHIS field that you want to preserve exactly:
- Skip steps 2 and 3 above. Instead, use the first tool, the converter, to make USGS-gtopo30_ne30np4pg2_16xdel2-PFC-consistentSGH_converted1 instead of ne30np4pg2_smoothed_phis1. This output nc file has the original GLL PHIS, now called PHIS_d, and the mapped pg2 PHIS data, as well as other pg2 fields we won't use.
- Run step 4 above with USGS-gtopo30_ne30np4pg2_16xdel2-PFC-consistentSGH_converted1 instead of ne30np4pg2_smoothed_phis1.
Run two ncks lines:
Code Block # Extract PHIS_d and ncol_d. ncks -v PHIS_d USGS-gtopo30_ne30np4pg2_16xdel2-PFC-consistentSGH_converted1.nc tmp.nc # Append PHIS_d and ncol_d to the topo file to create the final result. ncks -A tmp.nc USGS-gtopo30_ne30np4pg2_16xdel2.nc
Regional Refinement
Regionally refined grids require no special steps when using the physgrid because the regional refinement happens at the element level, and the physgrid only changes the physics column arrangement within the element.
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