NetCDF file

[Heiner Körnich]

Hi,

I just had a similar problem, but for me it worked with xdfopen after
several attempts. How did your ctl-file for xdfopen look like?

regards,
Heiner

On Thu, 2007-07-05 at 15:01 -0400, Li,Guilong [Ontario] wrote:
> Hi Everyone
>
> I am trying to read NCEP North American Regional Reanalysis data in
> NetCDF format. I tried to use sdfopen to open the file, but it gave me
> the following error message.
>
> SDF file has no discernable X coordinate.
>
> I checked the user group regarding this error message and it says
> "netcdf file was not constructed according to COARDS rules". I do not
> understand why sdfopen works for NCEP reanalysis data (2.5x2.5), but it
> doesn't work for NCEP NARR data. Anyway,I tried to use xdfopen to read
> NARR NetCDF data, it still doesn't work. The following is the "ncdump
> -c" output. Thanks.
>
> Guilong
>
> netcdf air.197901 {
> dimensions:
>         y = 277 ;
>         x = 349 ;
>         level = 29 ;netcdf air.197901
>         time = UNLIMITED ; // (248 currently)
> variables:
>         float level(level) ;
>                 level:units = "millibar" ;
>                 level:actual_range = 1000.f, 100.f ;
>                 level:long_name = "Level" ;
>                 level:positive = "down" ;
>                 level:GRIB_id = 100s ;
>                 level:GRIB_name = "hPa" ;
>                 level:axis = "Z" ;
>                 level:coordinate_defines = "point" ;
>         float lat(y, x) ;
>                 lat:long_name = "latitude coordinate" ;
>                 lat:units = "degrees_north" ;
>                 lat:standard_name = "latitude" ;
>                 lat:axis = "Y" ;
>                 lat:coordinate_defines = "point" ;
>         float lon(y, x) ;
>                 lon:units = "degrees_east" ;
>                 lon:long_name = "longitude coordinate" ;
>                 lon:standard_name = "longitude" ;
>                 lon:axis = "X" ;
>                 lon:coordinate_defines = "point" ;
>         double time(time) ;
>                 time:units = "hours since 1800-1-1 00:00:0.0" ;
>                 time:long_name = "time" ;
>                 time:actual_range = 1569072., 1569813. ;
>                 time:delta_t = "0000-00-00 03:00:00" ;
>                 time:standard_name = "time" ;
>                 time:axis = "T" ;
>                 time:coordinate_defines = "point" ;
>         float x(x) ;
>                 x:long_name = "eastward distance from southwest corner
> of domain in projection coordinates" ;
>                 x:units = "m" ;
>                 x:standard_name = "projection_x_coordinate" ;
>         float y(y) ;
>                 y:long_name = "northward distance from southwest corner
> of domain in projection coordinates" ;
>                 y:units = "m" ;
>                 y:standard_name = "projection_y_coordinate" ;
>         short air(time, level, y, x) ;
>                 air:long_name = "3-hourly Air Temperature on Pressure
> Levels" ;
>                 air:valid_range = -32765s, -10260s ;
>                 air:unpacked_valid_range = 137.5f, 362.5f ;
>                 air:actual_range = 189.3768f, 309.3121f ;
>                 air:units = "degK" ;
>                 air:add_offset = 465.15f ;
>                 air:scale_factor = 0.01f ;
>                 air:missing_value = 32766s ;
>                 air:_FillValue = -32767s ;
>                 air:precision = 2s ;
>                 air:least_significant_digit = 1s ;
>                 air:GRIB_id = 11s ;
>                 air:GRIB_name = "TMP" ;
>                 air:var_desc = "Air temperature" ;
>                 air:dataset = "NARR 3-hourly" ;
>                 air:level_desc = "Pressure Levels" ;
>                 air:statistic = "Individual Obs" ;
>                 air:parent_stat = "Other" ;
>                 air:standard_name = "air_temperature" ;
>                 air:grid_mapping = "Lambert_Conformal" ;
>                 air:coordinates = "lat lon" ;
>         int Lambert_Conformal ;
>                 Lambert_Conformal:grid_mapping_name =
> "lambert_conformal_conic" ;
>                 Lambert_Conformal:standard_parallel = 50., 50. ;
>                 Lambert_Conformal:longitude_of_central_meridian = -107.
> ;
>                 Lambert_Conformal:latitude_of_projection_origin = 50. ;
>                 Lambert_Conformal:false_easting = 5632642.22547 ;
>                 Lambert_Conformal:false_northing = 4612545.65137 ;
>
> // global attributes:
>                 :Conventions = "CF-1.0" ;
>                 :title = "8x Daily NARR" ;
>                 :history = "created 2005/07 by Hoop (netCDF2.3)" ;
>                 :comments = "Data is from North American Regional
> Reanalysis\n",
>     "(8x/day).  It consists of most variables interpolated to\n",
>     "pressure surfaces from model (sigma) surfaces." ;
>                 :institution = "National Centers for Environmental
> Prediction" ;
>                 :platform = "Model" ;
>                 :references =
> "http://wwwt.emc.ncep.noaa.gov/mmb/rreanl/index.html\n",
>     "http://www.cdc.noaa.gov/cdc/data.narr.html" ;
> }