CDO

Could you please attach the netCDF file or at least the netCDF header (ncdump -h)?

Here comes the header:

netcdf pco2_ant {
dimensions:
x = 122 ;
y = 101 ;
time = UNLIMITED ; // (12 currently)
variables:
double time(time) ;
time:units = "day as %Y%m%d.%f" ;
time:calendar = "proleptic_gregorian" ;
float scal_lon(y, x) ;
scal_lon:long_name = "2-d longitude of scalar grid cells" ;
scal_lon:units = "degree E" ;
scal_lon:_FillValue = 99999.f ;
float scal_lat(y, x) ;
scal_lat:long_name = "2-d longitude of scalar grid cells" ;
scal_lat:units = "degree N" ;
scal_lat:_FillValue = 99999.f ;
float pco2_ant(time, y, x) ;
pco2_ant:long_name = "ant. CO2 partial-pressure" ;
pco2_ant:units = "ppm" ;
pco2_ant:_FillValue = 99999.f ;

// global attributes:
:CDI = "Climate Data Interface version 1.4.5.1 (http://code.zmaw.de/projects/cdi)" ;
:Conventions = "CF-1.0" ;
:history = "Tue May 24 11:13:23 2011: cdo selname,pco2_ant,scal_lat,scal_lon bgcmean_2d.nc pco2_ant.nc\n",
"Mean monthly output for marine bgc modules" ;
:title = "Mean monthly output for marine bgc modules" ;
:conventions = "COARDS" ;
:date = 1991, 1, 31, 13035450, 11567770 ;
:CDO = "Climate Data Operators version 1.4.5.1 (http://code.zmaw.de/projects/cdo)" ;
}

Hi Iris,

The units of the coordinates have to follow exactly the CF convention. Otherwise it is not possible to detect the right coordinates. Here is a list of all acceptable units for longitude coordinates:

degrees_east, degree_east, degree_E, degrees_E, degreeE, and degreesE

ncatted -a units,scal_lon,m,c,"degreeE" -a units,scal_lat,m,c,"degreeN"  file.nc

Best regards,
Uwe

Hi Uwe,

thanks for your advice.
But unfortunately, it does not work.
I changed the attribute "units" of scal_lon and scal_lat as you suggested. When I did ncdump -h, the attributes appeared to be "degreeE" and "degreeN". Fine.
Then I tried again to create the attribute "coordinates" for pco2_ant using scal_lat and scal_lon. The value of the attribute then appears to be 0, which is weird.
And still, remapbil reports a generic grid which it does not support.
Right now, I am thinking about, if there is another way to provide remapbil with information about the grid. All I know about the grid is, that it is a orthogonal-curvilinear Cgrid as used in the MPI-OM.
I attach the file NeCDF-file, with which I have the remapping problem.

With many thanks for further help in advance,
Iris

Hi Iris,

You have to change the third parameter of the option -a in the call to ncatted. 'c' means create an attribute. You have to use 'm' to modify an existing attribute:

ncatted -a coordinates,pco2_ant,m,c,"scal_lon scal_lat" pco2_ant.nc

cdo remapbil,targetgrid  -setgrid,sourcegrid  ifile  ofile

Best regards,
Uwe