Isotope historical files are in NetCDF-4 format need them in NetCDF-3 or NetCDF-5

[ekluzek]

Brief summary of bug

@jedwards4b found that two files are in NetCDF-4 format and can't be read on the Korean system he is working in...

"I'm trying to run f09_g17.B1850cmip6 on the korean system using the 2.1.1 release candidate and am having trouble reading the files
/share/CESM/cesm_input/lnd/clm2/isotopes/atm_delta_C13_CMIP6_1850-2015_yearly_v2.0_c171012.nc

/share/CESM/cesm_input/lnd/clm2/isotopes/atm_delta_C14_CMIP6_3x1_global_1850-2015_yearly_v2.0_c171012.nc

It appears that the files were created using netcdf4 and pnetcdf is having trouble reading them. Using nccopy I made cdf5 versions of the files and that works,

General bug information

CTSM version you are using: release-clm5.0.24

Does this bug cause significantly incorrect results in the model's science? No

Configurations affected: Some external machines

Details of bug

Some external machines seem to have trouble reading in NetCDF-4 format files. This works OK on local machines. NERSC machines sometimes has this problem in addition to the Korean system. From Jim "The problem seems to be related to cray systems, but I haven't figured out exactly why." So the best way to handle it now is to change the file format to either NetCDF-3 or NetCDF-5.

[ekluzek]

Note, there are some datasets for mksurfdata_map that are in NetCDF format.

This one is required to be in NetCDF-4...

lnd/clm2/mappingdata/grids/UNSTRUCTgrid_0.5x0.5_AVHRR_c110228.nc

This one doesn't have to be....

lnd/clm2/rawdata/pftcftlandusedynharv.0.25x0.25.MODIS.simyr1850-2015.c170412/mksrf_soilcolor_simyr2005.c170413.nc netCDF-4 classic model