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Hybrid sigma pressure levels to pressure levels

Added by Rashed Mahmood over 4 years ago

Hi All,

I am trying to use the operator ml2pl to convert a model file from hybrid sigma pressure levels to pressure levels:

cdo ml2pl,100000,92500,85000,80000,70000,60000,50000,30000,25000,20000,15000,10000 -selname,cdnc tmp_fil000003.nc test.nc

However, I get the following error message:
Warning: No 3D variable with hybrid sigma pressure coordinate found!

From a previous message I tried to do:

ncatted -a bounds,lev,c,c,"ilev" tmp_fil000003.nc

The ncatted command does not seem to add ilev to the file, and I continue getting the above error message. A minimal file is attached, Any thoughts?
Thanks,
Rashed


Replies (1)

RE: Hybrid sigma pressure levels to pressure levels - Added by Karin Meier-Fleischer over 4 years ago

Hi Rashed,

if you have read the full warning message you would have seen that some variables are missing.

cdo ml2pl,100000,92500,85000,80000,70000,60000,50000,30000,25000,20000,15000,10000 -selname,cdnc tmp_fil000003.nc test.nc

cdo(2) selname: Process started
Warning (scan_hybrid_formulaterms): NetCDF: Variable not found - ap
Warning (scan_hybrid_formulaterms): NetCDF: Variable not found - b
Warning (scan_hybrid_formulaterms): NetCDF: Variable not found - ap_bnds
Warning (scan_hybrid_formulaterms): NetCDF: Variable not found - b_bnds
cdo ml2pl (Warning): No 3D variable with hybrid sigma pressure coordinate found!
cdo(2) selname: Processed 1213632 values from 2 variables over 3 timesteps
cdo ml2pl: Processed 1213632 values from 1 variable [0.05s 20MB]

The variables are needed to compute the given formula of lev

    double lev(lev) ;
        lev:standard_name = "atmosphere_hybrid_sigma_pressure_coordinate" ;
        lev:axis = "Z" ;
        lev:positive = "down" ;
        lev:long_name = "hybrid sigma pressure coordinate" ;
        lev:units = "1" ;
        lev:formula_terms = "ap: ap b: b ps: ps" ;
        lev:bounds = "lev_bnds" ;
        lev:formula = "p = ap + b*ps" ;

-Karin

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