CDO (Climate Data Operators) is a free and open-source software that provides over 600 command line operators for performing statistical analysis and data manipulation on climate and weather data. It allows users to select, subsample, interpolate, perform arithmetic operations and simple statistical analysis on netcdf and grib files. Some basic CDO commands include using conda to install CDO, using cdo info to get file information, cdo merge to combine files, and cdo copy to change file formats.

1. Climate Data Operators (CDO)
Arulalan.T
Scientist
India Meteorological Department

2. Climate Data Operators (CDO)
• CDO provides over 600 command line
operators for performing simple statistical and
arithmetic functions, selection and sub-
sampling and spatial interpolation of the
weather and climate data.
• Its is free and open source scientific software
• One can do quick plotting using CDO as well

3. Basics
• conda install cdo
• cdo info infile.nc
• cdo sinfo infile.nc
• cdo showvars infile.grib2
• cdo merge infile1.nc infile2.nc outfile.nc
• cdo mergetime infile1.nc infile2.nc outfile.nc
• cdo copy –f grb2 infile.nc outfile.grib2
• cdo copy –f nc infile.grib2 outfile.nc

4. Basics
• split
• splittime
• splitvar
• selvar
• seltime
• cdo selbox,lon1,lon2,lat1,lat2 ifile ofile

5. Selection

6. Selection

7. seltime

8. Comparison

9. Modification

10. Modification

11. Arithmetic

12. Arithmetic

13. Statistics

14. Statistics

15. Statistics

16. Statistics

17. Interpolation

18. Transformation

19. Import/Export

20. Miscellaneous

21. Miscellaneous

22. WMO Climate indices

23. WMO Climate indices

24. WMO Climate indices

25. References
• http://www.idris.fr/media/ada/cdo.pdf (CDO over 600
commands with examples)
• https://code.mpimet.mpg.de/projects/cdo/embedded/
cdo_eca.pdf (CDO ECA commands)
• https://code.mpimet.mpg.de/projects/cdo/wiki/Tutori
al (CDO from basics to plotting)
• https://duncanjg.files.wordpress.com/2008/02/cdo_ref
card.pdf CDO Cheat Sheet