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Generic grid to regular lon/lat grid

Added by praveen rai about 4 years ago

Hello all,
I have a model generated Orography dataset which I am trying to regrid but it is not working.
The CDO sinfo shows the following content-
File format : NetCDF2
-1 : Institut Source T Steptype Levels Num Points Num Dtype : Parameter ID
1 : MPIMET REMO v instant 1 1 15759 1 F32 : 129.128
Grid coordinates :
1 : generic : points=15759 (153x103)
Vertical coordinates :
1 : surface : levels=1
Time coordinate : 1 step
YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss
0020-04-17 00:00:00
I have even tried to add lon/lat using ncatted from nco but it also shows error when opening the file (Warning (cdf_scan_var_attr) : NetCDF: Variable not found - lat: Warning (cdf_scan_var_attr) : NetCDF: Variable not found - lon)
I am attaching my file also here.
Any help will be highly appreciated.

Thanks
Praveen


Replies (6)

RE: Generic grid to regular lon/lat grid - Added by Karin Meier-Fleischer about 4 years ago

Hi Praveen,

without the proper latitude and longitude or rather x and y data it is not possible to help.

-Karin

RE: Generic grid to regular lon/lat grid - Added by praveen rai about 4 years ago

Thanks for the reply Karin. I am attaching a regrid file from which I am trying to remap.

regrid (117 Bytes) regrid

RE: Generic grid to regular lon/lat grid - Added by Karin Meier-Fleischer about 4 years ago

Is regrid the grid description file of CAS-44_oro.nc?

cat regrid
gridtype  = lonlat
gridsize  = 15453
xsize     = 153
ysize     = 101
xfirst = 10.75
xinc=0.44
yfirst=17.75
yinc=0.44

If it is the correct grid file then you add the missing lat/lons to the data file by

cdo -setgrid,regrid CAS-44_oro.nc
ncdump -h out.nc
ncdump -h out.nc 
netcdf out {
dimensions:
    time = UNLIMITED ; // (1 currently)
    lon = 153 ;
    lat = 101 ;
variables:
    double time(time) ;
        time:standard_name = "time" ;
        time:units = "day as %Y%m%d.%f" ;
        time:calendar = "proleptic_gregorian" ;
        time:axis = "T" ;
    double lon(lon) ;
        lon:standard_name = "longitude" ;
        lon:long_name = "longitude" ;
        lon:units = "degrees_east" ;
        lon:axis = "X" ;
    double lat(lat) ;
        lat:standard_name = "latitude" ;
        lat:long_name = "latitude" ;
        lat:units = "degrees_north" ;
        lat:axis = "Y" ;
    float FIB(time, lat, lon) ;
        FIB:long_name = "surface geopotential (orography)" ;
        FIB:units = "m" ;
        FIB:code = 129 ;
        FIB:table = 128 ;
        FIB:institution = "MPIMET" ;

// global attributes:
        :CDI = "Climate Data Interface version 1.9.8 (https://mpimet.mpg.de/cdi)" ;
        :Conventions = "CF-1.6" ;
        :history = "Fri Apr 24 12:49:35 2020: cdo -f nc -setgrid,regrid CAS-44_oro.nc out.nc\n",
            "Tue Apr 14 17:14:37 2020: cdo -t remo -f nc copy CAS-44_oro.srv CAS-44_oro.nc" ;
        :source = "REMO" ;
        :institution = "Max-Planck-Institute for Meteorology" ;
        :CDO = "Climate Data Operators version 1.9.8 (https://mpimet.mpg.de/cdo)" ;
}

RE: Generic grid to regular lon/lat grid - Added by praveen rai about 4 years ago

The regrid file is not exactly the description file for the data. But it seems to work now.
Thank you so much Karin.

Greetings
Praveen

RE: Generic grid to regular lon/lat grid - Added by Ryan Murphy almost 4 years ago

Thanks for the code! Really helped, as i'm a typical newbie :)

Jing Stock

RE: Generic grid to regular lon/lat grid - Added by mh wahla almost 4 years ago

awesome thanks for code,

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