wiki:Documentation/UserGuide/CDO

Version 1 (modified by luyssaert, 7 years ago) (diff)

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Similar to Ferret (see also How To), CDO can also be used to regrid NetCDF files. It is very straight and fast. Contrary to Ferret I [SL] did not find how to increase the memory allocation for CDO. Thus for very large files Ferret seems to be the software of your choice.

The call has the following structure:

cdo -f nc -regriddingMethod,gridTemplate.nc input.nc output.nc

There are three regridding methods: remapbil (bilinear interpolation), remapbic (bicubic interpolation), remapnn (nearest neighbour), remapcon (conservative regridding). Use remapnn and remapcon to avoid weird values if your variable is heterogeneous.

For the template file with your target grid, it can be any netcdf with regular lat/lon. A trick here is to use "full paths" and not relative paths to the files in order to work.

Some examples:

cdo -f nc -remapbil,/gpfs/cru/rst08auu/code/target.0.5degree.gpp.grid.45N.nc esa.ecv.smo.0.25deg.grid.monthly.1979.2010.nc esa.ecv.smo.0.25deg.grid.monthly.1979.2010.cdo.remapped.0.5deg.remapbil.45N.nc
cdo -f nc -remapnn,/gpfs/cru/rst08auu/code/target.0.5degree.gpp.grid.45N.nc esa.ecv.smo.0.25deg.grid.monthly.1979.2010.nc esa.ecv.smo.0.25deg.grid.monthly.1979.2010.cdo.remapped.0.5deg.remapnn.45N.nc