Dear all,
We have a netCDF file containing ice concentrations around antarctica
that is available at
http://thredds.met.no/thredds/catalog/egiltest/ES/data/catalog.html?dataset=egiltest/ES/data/iceconc.nc.
Using the Godiva2 viewer, it is obvious that the data is displayed
inverted along a vertical line centred on the map. This is most easily
seen using the south polar stereographic projection.
The netCDF file has a variable containing projection info:
int Polar_Stereographic_Grid ;
Polar_Stereographic_Grid:grid_mapping_name =
"polar_stereographic" ;
Polar_Stereographic_Grid:straight_vertical_longitude_from_pole
= 0.f ;
Polar_Stereographic_Grid:latitude_of_projection_origin = -90.f ;
Polar_Stereographic_Grid:standard_parallel = -70.f ;
Polar_Stereographic_Grid:false_easting = 0.f ;
Polar_Stereographic_Grid:false_northing = 0.f ;
Polar_Stereographic_Grid:semi_major_axis = 6378273.f ;
Polar_Stereographic_Grid:semi_minor_axis = 6356890.f ;
Polar_Stereographic_Grid:proj4_string = "+proj=stere +a=6378273
+b=6356889.44891 +lat_0=-90 +lat_ts=-70 +lon_0=0" ;
When I removed the following attributes from this variable, the data
suddenly displayed correctly in Godiva2:
Polar_Stereographic_Grid:semi_major_axis = 6378273.f ;
Polar_Stereographic_Grid:semi_minor_axis = 6356890.f ;
The modified version can be seen at
http://thredds.met.no/thredds/catalog/egiltest/ES/data/catalog.html?dataset=egiltest/ES/data/iceconc_1.nc.
Since these attributes only gives a more exact description of the shape
of the earth (compared to not having them), I think there must be a bug
somewhere. Have anybody experienced this behaviour? Is this a known bug?
We are using thredds version 4.2.9.
Best regards,
Egil Støren
Norwegian Meteorological Institute
