Add ability to read MPAS "cdf5"-formatted output #329
Description
Is your feature request related to a problem? Please describe.
Starting with NCAR's release of MPAS v8.0.0, a new I/O layer called SMIOL has been added as an option. SMIOL allows the user to compile MPAS without having to compile the PIO library first (which is often a problematic build), thus simplifying the building of MPAS.
However, using the SMIOL I/O layer only produces CDF-5 (reported as "cdf5" when issuing an "ncdump -k file.nc" command) netCDF format for all output files from MPAS. And VERDI currently cannot read cdf5 files (as tested with the 20231013 build of VERDI 2.1.4).
CDF-5 format became available starting with NetCDF 4.4.0 (about 2016).
Describe the solution you'd like
Add the ability of VERDI to read the MPAS cdf5 format along with all other NetCDF format files that can be produced by MPAS (i.e., so VERDI can read cdf5, as well as the current 64-bit offset and netCDF-4 formats from MPAS).
For testing, MPAS output files in the cdf5 format are available on Atmos at:
/work/MOD3DEV/jherwehe/mpas/MPAS-v8.0.1-Release/run.92-25km.Jul2016.Noah_YSU_KF_WSM6_MODIS.SMIOL.RHEL8
Describe alternatives you've considered
The only work-around for VERDI not being able to read the cdf5 format is to use nccopy or an NCO command to convert the cdf5 MPAS output files to 64-bit offset format, which would be cumbersome. Better to have VERDI read cdf5 files directly.
Additional context
Here is the error that VERDI produces when attempting to read a cdf5 MPAS file:
