CDO

I forgot the information regarding the grids of the 'mygrid.nc' file, the other file also has a generic grid.

File format : NetCDF4
-1 : Institut Source T Steptype Levels Num Points Num Dtype : Parameter ID
1 : unknown unknown c instant 12 1 16200 1 F32 : -1
Grid coordinates :
1 : generic : points=16200 (180x90)
lon : -179 to 179 by 2
lat : 89 to -89 by -2

Hi Noam,

without the files I can only guess what you have to do.

Since the variable fractile has already a coordinates attribute you don't
have to add it anyway.

But the coordinate variables lon and lat have no units attribute and these
have to be added with ncatted.

ncatted -O -a units,lat,c,c,"degrees north" -a units,lon,c,c,"degrees east" frac.nc

Then it should look like

@netcdf frac {
dimensions:
patch = 12 ;
lon = 7200 ;
lat = 3600 ;
variables:
float patch(patch) ;
float lon(lon) ;
lon:units = "degrees_east" ;
float lat(lat) ;
lat:units = "degrees_north" ;
float fractile(patch, lat, lon) ;
fractile:_FillValue = 999.f ;
fractile:coordinates = "lon lat" ;

In your mygrid.nc file the variable LAI doesn't need to have a coordinates variable
because only the lon/lat grid is used. The units of lon and lat are missing here, too.

ncatted -O -a units,lat,c,c,"degrees north" -a units,lon,c,c,"degrees east" mygrid.nc

Now, remap the data:

cdo -remapbil,mygrid.nc frac.nc fracout.nc

-Karin

That worked Karin, thank you! I have learned something. So is it normal for 'lonlat' coordinates type to be 'degrees_east circular' or should they just be 'degrees_east'?

In general longitude and latitude coordinate variables should have units like "degrees_east"
(without circular) or "degrees_north". If you are interested in learning more about units see:
http://cfconventions.org/Data/cf-conventions/cf-conventions-1.7/build/ch03.html#units