CDO

OK, I manage to make CDO works over Embeded Ubuntu.
I've to put this command :

sudo strip --remove-section=.note.ABI-tag /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 

The cdo - V command returns :

Climate Data Operators version 1.9.9rc1 (https://mpimet.mpg.de/cdo)
System: x86_64-pc-linux-gnu
CXX Compiler: g++ -g -O2 -fdebug-prefix-map=/build/cdo-51aH2m/cdo-1.9.9~rc1=. -fstack-protector-strong -Wformat -Werror=format-security -fopenmp
CXX version : g++ (Ubuntu 9.2.1-28ubuntu1) 9.2.1 20200203
C Compiler: gcc -g -O2 -fdebug-prefix-map=/build/cdo-51aH2m/cdo-1.9.9~rc1=. -fstack-protector-strong -Wformat -Werror=format-security -Wall -pedantic -fPIC  -fopenmp
C version : gcc (Ubuntu 9.2.1-28ubuntu1) 9.2.1 20200203
F77 Compiler: f77 -g -O2 -fdebug-prefix-map=/build/cdo-51aH2m/cdo-1.9.9~rc1=. -fstack-protector-strong
F77 version : unknown
Features: 15GB 8threads C++14 Fortran DATA PTHREADS OpenMP HDF5 NC4/HDF5/threadsafe OPeNDAP SZ UDUNITS2 PROJ MAGICS CURL FFTW3 SSE2
Libraries: HDF5/1.10.4 proj/6.3.0 curl/7.68.0(h7.66.0)
Filetypes: srv ext ieg grb1 grb2 nc1 nc2 nc4 nc4c nc5
     CDI library version : 1.9.9rc1
 ecCodes library version : 2.16.0
  NetCDF library version : 4.7.3 of Jan 23 2020 04:18:16 $
    hdf5 library version : library undefined
    exse library version : 1.4.1
    FILE library version : 1.8.3

But I got this error when I execute the command : cdo -v -f grb2 -copy infile.nc output.grb

ECCODES ERROR   :  concept: no match for cfName=ocean_sigma_variable
ECCODES ERROR   :  concept: input handle edition=2
Here are the possible values for concept cfName:
        air_pressure_at_mean_sea_level
        air_temperature
        atmosphere_relative_vorticity
        depth_of_isosurface_of_sea_water_potential_temperature
        divergence_of_wind
        eastward_sea_water_velocity
        eastward_wind
        geopotential
        geopotential_height
        kinetic_energy_dissipation_in_atmosphere_boundary_layer
        lagrangian_tendency_of_air_pressure
        land_binary_mask
        northward_sea_water_velocity
        northward_wind
        ocean_mixed_layer_thickness_defined_by_sigma_theta
        relative_humidity
        sea_ice_area_fraction
        sea_ice_thickness
        sea_surface_height_above_geoid
        sea_surface_salinity
        specific_humidity
        surface_air_pressure
        surface_downward_eastward_stress
        surface_downward_northward_stress
        surface_downwelling_shortwave_flux_in_air
        surface_net_downward_longwave_flux_assuming_clear_sky
        surface_net_downward_shortwave_flux
        surface_net_downward_shortwave_flux_assuming_clear_sky
        surface_net_upward_longwave_flux
        surface_roughness_length
        surface_upward_latent_heat_flux
        surface_upward_sensible_heat_flux
        toa_outgoing_longwave_flux
!!! grib_set_string(    grib_handle* h, "cfName", "ocean_sigma_variable") !!!
Warning (gribapiDefParam): grib_api: No match for cfName=ocean_sigma_variable
ECCODES ERROR   :  concept: no match for shortName=SIG
ECCODES ERROR   :  concept: input handle edition=2
!!! grib_set_string(    grib_handle* h, "shortName", "SIG") !!!
Warning (gribapiDefParam): grib_api: No match for shortName=SIG
gribapiDefLevel   : Changed zaxis type from generic to pressure
Warning (gribapiDefLevel): Pressure level of -0.500000 Pa is below zero!
ECCODES ERROR   :  Key "scaledValueOfFirstFixedSurface": Trying to encode a negative value of -5 for key of type unsigned

!!! failed call to grib_set_long(       grib_handle* h, "scaledValueOfFirstFixedSurface", -5) !!!
../../../../libcdi/src/stream_gribapi.c at line 2377: my_grib_set_long(gh, "scaledValueOfFirstFixedSurface", scaled_level) failed: Encoding invalid

hi Aurélien!

the standard name cannot be found in your eccodes installation. you can change the standard_name attribute with the setattribute operator, but that won't help a lot. your input uses a projection, which cannot be saved in GRIB. sorry

cheers
ralf

OK, thank you.

Then I'll have to know the correspondances between my file attribute names and standards ones, is it right?
Is there a way to know the list of attributes names used in my file?

And to finish, how can I change the projection to make the conversion works?

you can use

 ncdump -h infile.nc

hth
ralf

you can interpolate the data onto a simpler regular grid

  # select a smaller region for data reduction
  cdo -sellonlatbox,-5,-1,45,48 infile.nc infileSel.nc

  # create grid file with the same region but finer resolution
  cdo -sellonlatbox,-5,-1,45,48 -topo,global_0.2 grid.nc

  # perform interpolation:
  #  nearest neighbour or
  cdo remapnn,grid.nc infileSel.nc infile_nn.nc
  # bilinear
  cdo remapbil,grid.nc infileSel.nc infile_bil.nc

hth
ralf

Thank you very much Ralf...

I go ahead with the conversion... But I still have an issue

gribapiDefLevel   : Changed zaxis type from generic to pressure
Warning (gribapiDefLevel): Pressure level of -0.500000 Pa is below zero!
ECCODES ERROR   :  Key "scaledValueOfFirstFixedSurface": Trying to encode a negative value of -5 for key of type unsigned

!!! failed call to grib_set_long(       grib_handle* h, "scaledValueOfFirstFixedSurface", -5) !!!
../../../../libcdi/src/stream_gribapi.c at line 2377: my_grib_set_long(gh, "scaledValueOfFirstFixedSurface", scaled_level) failed: Encoding invalid

It seems that it tries to put zaxis variable to atmospheric pressure... But with negatives values, that crashes!

I'm trying to cancel thi zaxis values...