GET_VARCOORDS - Cannot find "coordinates" attribute

[kee]

Hi all,

I made the atmpheric forcing file in my own way, and tried to run the model.
However, it doesnot work, and the messages is below.
Can anyone give some ideas?
Thanks in advance!

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GET_VARCOORDS - Cannot find "coordinates" attribute for variable:  uwnd
                 in file:  ./Inputs/roms_blk.nc

                 This attribute is needed to interpolate input data
                 to model grid. Following CF compliance, we need:

                 float my_var(time, lat, lon) ;
                       my_var:long_name = "my variable long name" ;
                       my_var:units = "my variable units" ;
                       my_var:coordinates = "lon lat" ;
                       my_var:time = "my_var_time" ;


 GET_2DFLD   - error while reading variable: uwnd   at TIME index =      12

Information of my roms_blk.nc file is

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	double uwnd(bulk_time, eta_u, xi_u) ;
		uwnd:long_name = "u-wind" ;
		uwnd:units = "m/s" ;
	double vwnd(bulk_time, eta_v, xi_v) ;
		vwnd:long_name = "v-wind" ;
		vwnd:units = "m/s" ;

[kate]

It is telling you that you need to add a coordinates attribute to your variables. You can use ncatted from the NCO package to edit your attributes. I expect you need a time attribute as well, pointing to the time variable dimensioned bulk_time.

[mtonelli]

I'm getting the same error at the very first time step:

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GET_VARCOORDS - Cannot find "coordinates" attribute for variable:  uwnd
                 in file:  raw_inputs/u_10_zero.nc

                 This attribute is needed to interpolate input data
                 to model grid. Following CF compliance, we need:

                 float my_var(time, lat, lon) ;
                       my_var:long_name = "my variable long name" ;
                       my_var:units = "my variable units" ;
                       my_var:coordinates = "lon lat" ;
                       my_var:time = "my_var_time" ;


 GET_2DFLD   - error while reading variable: uwnd   at TIME index =    1

I'm using CORE inter-annual forcing and I want ROMS to internally interpolate it to a Lat-Lon following grid. I've changed the variables and dimensions names as suggested in the wiki (here) and set the first time step to zero.

This is the ncdump -h for my u_10_zero.nc:

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netcdf u_10_zero {
dimensions:
	wind_time = UNLIMITED ; // (87600 currently)
	lat = 94 ;
	lon = 192 ;
	bnds = 2 ;
variables:
	double wind_time(wind_time) ;
		wind_time:axis = "T" ;
		wind_time:bounds = "TIME_bnds" ;
		wind_time:calendar = "NOLEAP" ;
		wind_time:time_origin = "1-JAN-1948" ;
		wind_time:units = "days since 1948-01-01 00:00:00" ;
	double lat(lat) ;
		lat:units = "degrees_north" ;
		lat:point_spacing = "uneven" ;
		lat:axis = "Y" ;
	double lon(lon) ;
		lon:units = "degrees_east" ;
		lon:modulo = 360. ;
		lon:point_spacing = "even" ;
		lon:axis = "X" ;
	double TIME_bnds(wind_time, bnds) ;
	float uwnd(wind_time, lat, lon) ;
		uwnd:missing_value = -1.e+34f ;
		uwnd:_FillValue = -1.e+34f ;
		uwnd:long_name = "10m U Wind" ;
		uwnd:units = "m/s" ;

Any thoughts?
Thanks in advance!

[arango]

You cannot use this file as it is in ROMS. It needs the coordinates attribute as mentioned in the error message. ROMS needs this attribute to process your data. It is very simple to fix. Use the provided nc_attadd from ROMS Matlab reposiotry:

nc_attadd('u_10_zero.nc', 'coordinates', 'lon lat wind_time', 'uwnd')

Notice that your CORE file has large values for the _FillValue attribute. ROMS will replace such values with zeros before interpolating. The missing_value is a deprecated attribute and not CF compliant. ROMS will not process the missing_value attribute. You need to check the data to see it actually have missing values and process them accordingly. They should be replaced with a _FillValue or a data value.

Now, ROMS metadata is specified in the file ROMS/External/varinfo.dat. For wind we have the following variable names:

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  'Uwind'                                          ! Input
  'surface u-wind component'
  'meter second-1'                                 ! [m/s]
  'u-wind, scalar, series'
  'wind_time'
  'idUair'
  'r2dvar'
  1.0d0

'Vwind'                                            ! Input
  'surface v-wind component'
  'meter second-1'                                 ! [m/s]
  'v-wind, scalar, series'
  'wind_time'
  'idVair'
  'r2dvar'
  1.0d0

Your variable (uwnd) does not have the same name as the above entries for wind (Uwind). You need to have a copy of this file in your application directory and edit the metadata appropriately to reflect the names in your input NetCDF file. Or you need to rename the variable in your NetCDF file:

status=nc_vrename('u_10_zero.nc', 'uwnd', 'Uwind')

This script is in ROMS Matlab repository.

[yourgod_mwt_cn]

I checked the forcing data in the dir. of the case test. The attribute should be as

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variables:
	double sst_time(sst_time) ;
		sst_time:long_name = "time for sea surface temperature" ;
		sst_time:units = "days since 1968-05-23 00:00:00 GMT" ;
		sst_time:calendar = "gregorian" ;
	float SST(sst_time, eta_rho, xi_rho) ;
		SST:long_name = "sea surface temperature" ;
		SST:units = "Celsius" ;
		SST:time = "sst_time" ;
		SST:coordinates = "lon lat" ;
		SST:flag_values = 9.999e+30f ;
		SST:flag_meanings = "land" ;
	float lon(eta_rho, xi_rho) ;
		lon:long_name = "longitude" ;
		lon:units = "degree_east" ;
		lon:standard_name = "longitude" ;
	float lat(eta_rho, xi_rho) ;
		lat:long_name = "latitude" ;
		lat:units = "degree_north" ;
		lat:standard_name = "latitude" ;
	float landval(one) ;