[ncl-talk] How to convert netcdf to grib format
Guido Cioni
guidocioni at gmail.com
Mon Feb 13 03:49:01 MST 2017
Arunima, this is ncl-talk, not cdo-talk :)
If CDO and NCL are having an hard time trying to convert your file *maybe* the problem is the file itself. Please read the appropriate documentation for CDO (https://code.zmaw.de/projects/cdo/wiki <https://code.zmaw.de/projects/cdo/wiki>).
By reading the CDO guide you would furthermore discover that the correct syntax of the command copy is the following:
cdo -f nc copy input_file.grb output_file.nc
and not the other way around. I suspect that won't fix the problem, but better starting from a clean state.
Good luck
Guido Cioni
http://guidocioni.altervista <http://guidocioni.altervista/>.org
> On 13 Feb 2017, at 11:39, Arunima Singh <arunima at vassarlabs.com> wrote:
>
> Hi,
>
> I am running following command -
> cdo -f grb setgrid,mygrid DET_10N20N_76E85E_2016111712.nc DET_10N20N_76E85E_2016111712.grib
>
> But getting following error:
> Warning (cgribexDefGrid) : The CGRIBEX library can not store fields on the used grid!
>
> Error (cgribexDefGrid) : Unsupported grid type: generic
>
> Am I doing something wrong, or is it because generic grid type is not supported.
> PFA files for reference.
>
> Is there any other way to convert netcdf to grib2 format.
>
> SAMPLE FILES:
> mygrid file ::
>
> gridtype = generic
> xsize = 73
> ysize = 81
> xfirst = 76
> xinc = 0.005
> yfirst = 20
> yinc = 0.005
>
> cdo griddes output::
> #
> # gridID 1
> #
> gridtype = generic
> gridsize = 81
> xsize = 81
> #
> # gridID 2
> #
> gridtype = generic
> gridsize = 73
> xsize = 73
> #
> # gridID 3
> #
> gridtype = generic
> gridsize = 5913
> xsize = 73
> ysize = 81
> cdo griddes: Processed 10 variables ( 0.00s )
>
>
> NetCDF file::
> latitude = 20, 19.875, 19.75, 19.625, 19.5, 19.375, 19.25, 19.125, 19,
> 18.875, 18.75, 18.625, 18.5, 18.375, 18.25, 18.125, 18, 17.875, 17.75,
> 17.625, 17.5, 17.375, 17.25, 17.125, 17, 16.875, 16.75, 16.625, 16.5,
> 16.375, 16.25, 16.125, 16, 15.875, 15.75, 15.625, 15.5, 15.375, 15.25,
> 15.125, 15, 14.875, 14.75, 14.625, 14.5, 14.375, 14.25, 14.125, 14,
> 13.875, 13.75, 13.625, 13.5, 13.375, 13.25, 13.125, 13, 12.875, 12.75,
> 12.625, 12.5, 12.375, 12.25, 12.125, 12, 11.875, 11.75, 11.625, 11.5,
> 11.375, 11.25, 11.125, 11, 10.875, 10.75, 10.625, 10.5, 10.375, 10.25,
> 10.125, 10 ;
>
> longitude = 76, 76.125, 76.25, 76.375, 76.5, 76.625, 76.75, 76.875, 77,
> 77.125, 77.25, 77.375, 77.5, 77.625, 77.75, 77.875, 78, 78.125, 78.25,
> 78.375, 78.5, 78.625, 78.75, 78.875, 79, 79.125, 79.25, 79.375, 79.5,
> 79.625, 79.75, 79.875, 80, 80.125, 80.25, 80.375, 80.5, 80.625, 80.75,
> 80.875, 81, 81.125, 81.25, 81.375, 81.5, 81.625, 81.75, 81.875, 82,
> 82.125, 82.25, 82.375, 82.5, 82.625, 82.75, 82.875, 83, 83.125, 83.25,
> 83.375, 83.5, 83.625, 83.75, 83.875, 84, 84.125, 84.25, 84.375, 84.5,
> 84.625, 84.75, 84.875, 85 ;
>
>
> On Mon, Feb 13, 2017 at 3:44 PM, Arunima Singh <arunima at vassarlabs.com <mailto:arunima at vassarlabs.com>> wrote:
> Hi,
>
> I am running following command -
> cdo -f grb setgrid,mygrid DET_10N20N_76E85E_2016111712.nc DET_10N20N_76E85E_2016111712.grib
>
> But getting following error:
> Warning (cgribexDefGrid) : The CGRIBEX library can not store fields on the used grid!
>
> Error (cgribexDefGrid) : Unsupported grid type: generic
>
> Am I doing something wrong, or is it because generic grid type is not supported.
> PFA files for reference.
>
> Is there any other way to convert netcdf to grib2 format.
>
> Thanks and Regards,
> Arunima Singh
>
> On Mon, Feb 13, 2017 at 1:30 PM, Beáta Szábo-Takács <szabo.b at czechglobe.cz <mailto:szabo.b at czechglobe.cz>> wrote:
>
> Hi,
>
> It hard to see the grid type by ncdump results. Can you apply Climate Data Operator (CDO)? If yes, you can see the grid coordinates with the sinfo or griddes operators:
>
> cdo sinfo file.nc <http://file.nc/>
>
> cdo griddes file.nc <http://file.nc/>
>
> You can create mygrid file by the following way:
>
> cat > mygrid << EOF
> gridtype =
> xsize =
> ysize =
> xfirst =
> xinc =
> yfirst =
> yinc =
> EOF
> I hope I could help you.
>
> Beata
>
>
> From: Arunima Singh <arunima at vassarlabs.com <mailto:arunima at vassarlabs.com>>
> Sent: Monday, February 13, 2017 8:32:49 AM
> To: Beáta Szábo-Takács
> Cc: Barry Lynn; ncl-talk
>
> Subject: Re: [ncl-talk] How to convert netcdf to grib format
>
> Hi,
>
> Thanks .
> Can you please tell me what to have in mygrid ?
>
> My netcdf file has following variables :
> netcdf DET_10N20N_76E85E_2016111712 {
> dimensions:
> lat = 81 ;
> lon = 73 ;
> time = 41 ;
> variables:
> float latitude(lat) ;
> latitude:units = "degrees_north" ;
> float longitude(lon) ;
> longitude:units = "degrees_east" ;
> float time(time) ;
> time:units = "hours since 2016-11-17 12Z" ;
> float \2m_temperature(time, lat, lon) ;
> \2m_temperature:units = "C" ;
> float \2m_relative_humidity(time, lat, lon) ;
> \2m_relative_humidity:units = "%" ;
> float mean_sea_level_pressure(time, lat, lon) ;
> mean_sea_level_pressure:units = "Pa" ;
> float \6hr_accumulated_precip(time, lat, lon) ;
> \6hr_accumulated_precip:units = "mm" ;
> float \10m_U_wind(time, lat, lon) ;
> \10m_U_wind:units = "m/s" ;
> float \10m_V_wind(time, lat, lon) ;
> \10m_V_wind:units = "m/s" ;
> float wind_magnitude(time, lat, lon) ;
> wind_magnitude:units = "m/s" ;
> float wind_direction(time, lat, lon) ;
> wind_direction:units = "degrees" ;
> }
>
>
> On Mon, Feb 13, 2017 at 12:56 PM, Beáta Szábo-Takács <szabo.b at czechglobe.cz <mailto:szabo.b at czechglobe.cz>> wrote:
> Hi,
>
> According to CDO support:
>
> The grid type generic means that the variables have either no grid information or the grid information is not supported in CDO.
> In both cases it is not possible to store the data in GRIB format. Here is a list of all supported CDO GRIB grid types:
>
> Latitude/longitude grid
> Lambert conformal grid
> Gaussian latitude/longitude grid
> Rotated latitude/longitude grid
> Spherical Harmonic Coefficients
> Icosahedral-hexagonal GME grid
> You have to add the missing grid information with setgrid if there is no grid information in your file and the variables are stored on one of the above grids:
>
> cdo -f grb setgrid,mygrid cc.nc <http://cc.nc/> cc.grb
>
> You can check the grid information of the variables with the CDO function sinfo or griddes.
>
>
>
> I hope I could help you.
>
>
>
> Beata
>
>
>
>
>
> From: Arunima Singh [mailto:arunima at vassarlabs.com <mailto:arunima at vassarlabs.com>]
> Sent: Monday, February 13, 2017 8:16 AM
> To: Beáta Szábo-Takács <szabo.b at czechglobe.cz <mailto:szabo.b at czechglobe.cz>>
> Cc: Barry Lynn <barry.h.lynn at gmail.com <mailto:barry.h.lynn at gmail.com>>; ncl-talk <ncl-talk at ucar.edu <mailto:ncl-talk at ucar.edu>>
>
>
> Subject: Re: [ncl-talk] How to convert netcdf to grib format
>
>
>
> I tried cdo -
>
> cdo -f grb copy DET_10N20N_76E85E_2016111712.nc DET_10N20N_76E85E_2016111712.grib
>
>
>
> but i am getting following error :
>
>
>
> Warning (cgribexDefGrid) : The CGRIBEX library can not store fields on the used grid!
>
>
>
> Error (cgribexDefGrid) : Unsupported grid type: generic
>
>
>
>
>
> On Mon, Feb 13, 2017 at 12:40 PM, Beáta Szábo-Takács <szabo.b at czechglobe.cz <mailto:szabo.b at czechglobe.cz>> wrote:
>
> Hi,
>
>
>
> I think you can convert netcdf to grib by CDO. Try the following operator:
>
>
>
> cdo -f grb copy file.nc <http://file.nc/> file.grb
>
>
>
> I hope it helps.
>
>
>
> Beata
>
>
>
> From: ncl-talk-bounces at ucar.edu <mailto:ncl-talk-bounces at ucar.edu> [mailto:ncl-talk-bounces at ucar.edu <mailto:ncl-talk-bounces at ucar.edu>] On Behalf Of Arunima Singh
> Sent: Monday, February 13, 2017 8:05 AM
> To: Barry Lynn <barry.h.lynn at gmail.com <mailto:barry.h.lynn at gmail.com>>
> Cc: ncl-talk <ncl-talk at ucar.edu <mailto:ncl-talk at ucar.edu>>
> Subject: Re: [ncl-talk] How to convert netcdf to grib format
>
>
>
> Hi,
>
>
>
> What i want is netcdf to grib2 format instead of grib to netcdf.
>
>
>
> Thanks and Regards,
>
> Arunima Singh
>
>
>
>
>
> On Mon, Feb 13, 2017 at 12:31 PM, Barry Lynn <barry.h.lynn at gmail.com <mailto:barry.h.lynn at gmail.com>> wrote:
>
> Hi:
>
>
>
> I believe you can find the answer here:
>
>
>
> http://www.ncl.ucar.edu/Applications/griball.shtml <http://www.ncl.ucar.edu/Applications/griball.shtml>
>
>
> On Mon, Feb 13, 2017 at 8:56 AM, Arunima Singh <arunima at vassarlabs.com <mailto:arunima at vassarlabs.com>> wrote:
>
> Hi,
>
>
>
> I have one netcdf file that i want to convert to grib format.
>
> Can we do this conversion with ncl?
>
>
>
> If yes, how?
>
>
>
> Thanks and Regards,
>
> Arunima Singh
>
>
>
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>
> --
>
> Barry H. Lynn, Ph.D
>
> Senior Lecturer,
>
> The Institute of the Earth Science,
> The Hebrew University of Jerusalem,
> Givat Ram, Jerusalem 91904, Israel
>
> Tel: 972 547 231 170
> Fax: (972)-25662581
>
>
>
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