As recommended in 
https://github.com/cf-convention/cf-conventions/issues/222#issuecomment-569789956,
 I'm inquiring as to whether **EASE Grid North 25 km original** ([EPSG 
3408](https://epsg.io/3408)) can be represented using grid_mapping attributes.  
My team generates hydrologic simulation model data for Arctic regions using 
that projection. I'd like to store data in CF netCDF, but I don't know if I'm 
doing it correctly.  Like [Jim 
says](https://github.com/cf-convention/cf-conventions/issues/222#issuecomment-570276738),
 there's a good chance I botched it.  In particular, there appears to be a 
number in the WKT related to the degree unit (0.0174532925199433), and I don't 
know if or how that should be represented in grid_mapping.  Here's my attempt 
at a grid_mapping variable, which includes a crs_wkt attribute. How does it 
look?

```java
int nsidc_ease_grid_north_25km;
  nsidc_ease_grid_north_25km:grid_mapping_name = "NSIDC_EASE_Grid_North";
  nsidc_ease_grid_north_25km:longitude_of_projection_origin = 0.0;
  nsidc_ease_grid_north_25km:latitude_of_projection_origin = 90.0;
  nsidc_ease_grid_north_25km:false_easting = 0.0;
  nsidc_ease_grid_north_25km:false_northing = 0.0;
  nsidc_ease_grid_north_25km:geographic_crs_name = 
"GCS_Sphere_International_1924_Authalic";
  nsidc_ease_grid_north_25km:horizontal_datum_name = 
"Not_specified_based_on_International_1924_Authalic_Sphere";
  nsidc_ease_grid_north_25km:reference_ellipsoid_name = "International 1924 
Authalic Sphere";
  nsidc_ease_grid_north_25km:semi_major_axis = 6371228.0;
  nsidc_ease_grid_north_25km:inverse_flattening = 0.0;
  nsidc_ease_grid_north_25km:prime_meridian_name = "Greenwich";
  nsidc_ease_grid_north_25km:longitude_of_prime_meridian = 0.0;
  nsidc_ease_grid_north_25km:projected_crs_name = 
"Lambert_Azimuthal_Equal_Area";
  nsidc_ease_grid_north_25km:longitude_of_central_meridian  = 0.0;
  nsidc_ease_grid_north_25km:crs_wkt = "PROJCS[\"NSIDC EASE-Grid 
North\",GEOGCS[\"Unspecified datum based upon the International 1924 Authalic 
Sphere\",DATUM[\"Not_specified_based_on_International_1924_Authalic_Sphere\",SPHEROID[\"International
 1924 Authalic 
Sphere\",6371228,0,AUTHORITY[\"EPSG\",\"7057\"]],AUTHORITY[\"EPSG\",\"6053\"]],PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\",0.0174532925199433,AUTHORITY[\"EPSG\",\"9122\"]],
   AUTHORITY[\"EPSG\",\"4053\"]],PROJECTION[\"Lambert_Azimuthal_Equal_Area\"],  
 PARAMETER[\"latitude_of_center\",90],PARAMETER[\"longitude_of_center\",0],   
PARAMETER[\"false_easting\",0],PARAMETER[\"false_northing\",0],UNIT[\"metre\",1,
   
AUTHORITY[\"EPSG\",\"9001\"]],AXIS[\"X\",EAST],AXIS[\"Y\",NORTH],AUTHORITY[\"EPSG\",\"3408\"]]"
 ;
```

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