modern diag manager: remove non-standard time bounds

[ceblanton]

Is your feature request related to a problem? Please describe. FMS history output includes time bounds metadata both in CF standard and non-standard conventions.

The CF standard time bounds are:

    double time(time) ;
        time:units = "days since 1979-01-01 00:00:00" ;
        time:long_name = "time" ;
        time:axis = "T" ;
        time:calendar_type = "JULIAN" ;
        time:calendar = "julian" ;
        time:bounds = "time_bnds" ;
    double time_bnds(time, nv) ;
        time_bnds:units = "days since 1979-01-01 00:00:00" ;
        time_bnds:long_name = "time axis boundaries" ;

And the non-standard, duplicated, time bounds are:

    float loadpoa(time, grid_yt, grid_xt) ;
        loadpoa:_FillValue = 1.e+20f ;
        loadpoa:missing_value = 1.e+20f ;
        loadpoa:units = "kg m-2" ;
        loadpoa:long_name = "Load of Dry Aerosol Primary Organic Matter" ;
        loadpoa:cell_methods = "time: mean" ;
        loadpoa:cell_measures = "area: area" ;
        loadpoa:time_avg_info = "average_T1,average_T2,average_DT" ;
        loadpoa:standard_name = "atmosphere_mass_content_of_primary_particulate_organic_matter_dry_aerosol" ;
    double average_T1(time) ;
        average_T1:_FillValue = 1.e+20 ;
        average_T1:missing_value = 1.e+20 ;
        average_T1:units = "days since 1979-01-01 00:00:00" ;
        average_T1:long_name = "Start time for average period" ;
    double average_T2(time) ;
        average_T2:_FillValue = 1.e+20 ;
        average_T2:missing_value = 1.e+20 ;
        average_T2:units = "days since 1979-01-01 00:00:00" ;
        average_T2:long_name = "End time for average period" ;
    double average_DT(time) ;
        average_DT:_FillValue = 1.e+20 ;
        average_DT:missing_value = 1.e+20 ;
        average_DT:units = "days" ;
        average_DT:long_name = "Length of average period" ;

Describe the solution you'd like The average_(T1|T2|DT) variables should not be included in modern diag manager history output.

(FRE-NCtools needs two corresponding updates tracked in https://github.com/NOAA-GFDL/FRE-NCtools/issues/273 and https://github.com/NOAA-GFDL/FRE-NCtools/issues/274.

Describe alternatives you've considered Most standard Netcdf tools respect the CF standard time bounds but not the FMS time bounds, so it would make FMS output more usable to omit the non-standard time bounds.

Additional context We previewed doing this at the MI meeting on 2024-02-14 and there were no protests.

[uramirez8707]

Fixed in #1505