CDO

hi Fredrik!

in order to link the corners to the centers, you have to use the bounds attribute for the centers like this

        double lon(ncells) ;
                lon:standard_name = "longitude" ;
                lon:long_name = "center longitude" ;
                lon:units = "radian" ;
                lon:bounds = "lon_vertices" ;
        double lon_vertices(ncells, vertices) ;

hth
ralf

Thanks!
Should I add this to all 3 files?

(I'm not that experienced with cdo/nco so feel free to explain more in detail)

/Fredrik

I have now added the bounds attribute to the grid_corners_SAFRAN.nc file (see attached file).
But now I get an error message stating that the file contains illegal characters (when doing the cdo remapcon line given above).
If i try to do a cdo info I get "Open failed - unsupported file structure".

Please advice.

/Fredrik

hi!

it was some manual work, but I guess I merges the variables. please check the new upload.

some general hints

• use the 'bounds' attribute whenever possible - it helps linking data and its coordinates
• put data and all coordinate information in the same file
• cdo needs a data-variable (CF-Convention) to work on a file - that's why 'grid_corners'-file cannot be used directly with setgrid.

hth
ralf

Hi Fredrik,

first your EUR-11_grid.nc don't have the lon_bnds and lat_bnds variables. If you do an ncdump -h on a correct file the first lines would look like this

netcdf EUR-11_grid_info {
dimensions:
    rlon = 424 ;
    rlat = 412 ;
    vertices = 4 ;
    time = UNLIMITED ; // (1 currently)
    bnds = 2 ;
variables:
    float lon(rlat, rlon) ;
        lon:standard_name = "longitude" ;
        lon:long_name = "longitude" ;
        lon:units = "degrees_east" ;
        lon:_CoordinateAxisType = "Lon" ;
        lon:bounds = "lon_bnds" ;
    float lon_bnds(rlat, rlon, vertices) ;
    float lat(rlat, rlon) ;
        lat:standard_name = "latitude" ;
        lat:long_name = "latitude" ;
        lat:units = "degrees_north" ;
        lat:_CoordinateAxisType = "Lat" ;
        lat:bounds = "lat_bnds" ;
    float lat_bnds(rlat, rlon, vertices) ;

To add the grid_corner_lat and grid_corner_lon variables to your data file you can use NCL (http://ncl.ucar.edu/). I wrote an NCL script which reads the files SAFRAN_PR_19890101net3.nc and the grid_corners_SAFRAN.nc and write everything needed to a new file SAFRAN_PR_19890101net3_added_vertices.nc.

Run NCL script in the data directory

ncl read_data_and_grid_corner_write_data_and_grid_corners.ncl

and run cdo as mentioned before, but with the correct EUR-11 grid file

cdo -remapcon,EUR-11_grid_info.nc SAFRAN_PR_19890101net3_added_grid_corners.nc ofile_EUR11_grid_corners.nc

Bye,
Karin