extdata.yaml

extdata.yaml is the configuration file for the next-generation MAPL ExtData component, usually referred to as ExtData2G. It serves the same purpose as ExtData.rc — telling GCHP which input variables to read, from which files, and how to regrid and time-interpolate them — but uses a YAML format with a simpler interface. ExtData2G will replace ExtData.rc in GCHP v15.0, when MAPL version 3 is integrated into GCHP.

Attention

ExtData2G is a beta feature. It is off by default, and extdata.yaml is only provided for the simulations listed below.

Availability

extdata.yaml is copied into the run directory only for the TransportTracers and TagO3 simulations. Other simulations have no extdata.yaml template yet and must use ExtData.rc.

The file that is installed is configured for MERRA-2 meteorology at grid resolutions of C180 or coarser. If you wish to use another meteorology source, use mass fluxes, or run at a resolution finer than C180, you will need to edit extdata.yaml yourself so that it matches the corresponding changes you would have made in ExtData.rc.

Enabling ExtData2G

Set Use_ExtData2G to true in the MAPL ExtData versions section of setCommonRunSettings.sh:

#------------------------------------------------
#   MAPL ExtData versions
#------------------------------------------------
# Set to true to use ExtData2G in MAPL (requires yaml input file)

Use_ExtData2G=false

and then execute the script so that it propagates the setting:

$ ./setCommonRunSettings.sh

This sets GCHP.rc’s USE_EXTDATA2G field and CAP.rc’s USE_EXTDATA2G field to .true., which is what causes MAPL to read extdata.yaml instead of ExtData.rc. Any value other than true or false causes setCommonRunSettings.sh to exit with an error.

Further reading

GMAO/NASA documentation for the file format is maintained on the ExtData Next Generation User Guide.