A question about polar stereographic projection

[Ted Pollock]

Hi,

Have you tried the FILEHEADER option in your ctl file? You can get
grads to skip past all the NetCDF data description information and
read only the raw data this way.

Unfortunately I couldn't get the yrev option working with the pdef
option for some reason and that might be necessary with polar data. I
would appreciate it if anyone might be able to provide some
information on that.

Good luck with it,

Ted


Quoting "Li,Guilong [Ontario]" <Guilong.Li at EC.GC.CA>:

> Dear Grads users,
>
> I have a netcdf file with polar stereographic projection which can not
> be opened by sdfopen. When I check the user group, I find I have to
> write a control file to overwrite sdf file. After I tried several times
> to write a new control file to open this netcdf file, it doesn't work.
>
> Can someone help me about this question? Thanks a lot.
>
> Guilong
>
> Here is the ncdump -h output.
>
> netcdf pr_MRCC_1979010103 {
> dimensions:
>         xc = 140 ;
>         yc = 115 ;
>         time = UNLIMITED ; // (5848 currently)
>         bnds = 2 ;
> variables:
>         double yc(yc) ;
>                 yc:units = "m" ;
>                 yc:long_name = "y-coordinate of polar_stereographic
> projection" ;
>                 yc:standard_name = "projection_y_coordinate" ;
>                 yc:axis = "Y" ;
>                 yc:coordinate_defines = "point" ;
>                 yc:actual_range = 0.f, 5700000.f ;
>         double xc(xc) ;
>                 xc:units = "m" ;
>                 xc:long_name = "x-coordinate of polar_stereographic
> projection" ;
>                 xc:standard_name = "projection_x_coordinate" ;
>                 xc:axis = "X" ;
>                 xc:coordinate_defines = "point" ;
>                 xc:actual_range = 0.f, 6950000.f ;
>         double time(time) ;
>                 time:long_name = "time" ;
>                 time:calendar = "gregorian" ;
>                 time:standard_name = "time" ;
>                 time:axis = "T" ;
>                 time:units = "days since 1979-01-01 00:00:0.0" ;
>                 time:delta_t = "0000-00-00 03:00:00" ;
>                 time:coordinate_defines = "point" ;
>                 time:actual_range = 0.125f, 731.f ;
>                 time:bounds = "time_bnds" ;
>         double lon(yc, xc) ;
>                 lon:units = "degrees_east" ;
>                 lon:long_name = "longitude" ;
>                 lon:standard_name = "longitude" ;
>                 lon:axis = "X" ;
>                 lon:actual_range = 199.8962f, 326.4349f ;
>         double lat(yc, xc) ;
>                 lat:units = "degrees_north" ;
>                 lat:long_name = "latitude" ;
>                 lat:standard_name = "latitude" ;
>                 lat:axis = "Y" ;
>                 lat:actual_range = 20.60496f, 73.2522f ;
>         char polar_stereographic ;
>
> polar_stereographic:straight_vertical_longitude_from_pole = 263.f ;
>                 polar_stereographic:standard_parallel = 60.f ;
>                 polar_stereographic:false_easting = -3525000.f ;
>                 polar_stereographic:false_northing = -7525000.f ;
>                 polar_stereographic:latitude_of_projection_origin = 90.f
> ;
>                 polar_stereographic:grid_mapping_name =
> "polar_stereographic" ;
>                 polar_stereographic:resolution_at_standard_parallel =
> 50000.f ;
>         float pr(time, yc, xc) ;
>                 pr:units = "kg m-2 s-1" ;
>                 pr:type = "average" ;
>                 pr:long_name = "Precipitation" ;
>                 pr:standard_name = "precipitation_flux" ;
>                 pr:cell_methods = "time: mean (interval: 3 hours)" ;
>                 pr:missing_value = 1.e+20f ;
>                 pr:_FillValue = 1.e+20f ;
>                 pr:actual_range = 0.f, 0.003506777f ;
>                 pr:add_offset = 0.f ;
>                 pr:scale_factor = 1.f ;
>                 pr:coordinates = "lon lat" ;
>                 pr:grid_mapping = "polar_stereographic" ;
>                 pr:level_desc = "Surface" ;
>                 pr:grid_desc = "polar_stereographic" ;
>         double time_bnds(time, bnds) ;
>
> // global attributes:
>                 :institution = "Ouranos (Ouranos, Montreal, PQ, Canada)"
> ;
>                 :source =
> "MRCC(2006):atmosphere:MRCCv4.2.0(50km,29levels):sea
> ice:AMIPII:land:CLASSv2.7" ;
>                 :project_id = "NARCCAP" ;
>                 :realization = "1" ;
>                 :experiment_id = "present-day climate using NCEP/DOE
> Reanalysis" ;
>                 :contact1 = "Sebastien Biner" ;
>                 :contact2 = "biner.sebastien at ouranos.ca" ;
>                 :contact3 = "550 Sherbrooke Ouest, 19e etage, Montreal,
> PQ, H3A 1B9, Canada" ;
>                 :contact4 = "tel : (514)282.6464 poste 263" ;
>                 :history = "created 24/04/2004 by Ton Nom (netCDF3.6.1
> udunits1.12.4)" ;
>                 :table_id = "Table 2" ;
>                 :Conventions = "CF-1.0" ;
> }
>
>