Overview

Teaching: 15 min
Exercises: 5 min

Questions

• How can I work with climate data outside of Python?

Objectives

Manipulating NetCDF files

ncdump ncdiff

There are a whole bunch of pre-made analyses in the CDO and NCO libraries

Available at NCI through modules, or on Conda in the ‘conda-forge’ channel

Work with files on disk or over OPENDAP

Easier to use existing tools than writing your own

Come with OpenMP threading optimisations

NCO:

Concatenate files, ensemble averaging,

Lots of options, complex ‘kitchen-sink’ operator

Right tool for modifying attributes (add, delete change)

move variables, basic math

CDO: Basic stats for each variable (min, mean, max) cdo infon FILE - Check for extremes

Compare two files cdo diff FILEA FILEB - Check model reproducibility

• Modificiation
  • Masks, attributes
• Arithmetic
• Statistics
• Correlations
• Interpolation

References

• http://nco.sourceforge.net/nco.html
• https://code.zmaw.de/projects/cdo

NetCDF viewers

Panoply

Allows a variety of plot types, combine u and v vector data. Available at NCI on VDI only

Ncview, available at nci

Quick & simple viewer

References

• http://www.giss.nasa.gov/tools/panoply/
• http://meteora.ucsd.edu/~pierce/ncview_home_page.html

Example: Calculating a seasonal average from the command line

Let’s see how we can use nco and cdo

Notebook

What tools do you use?

There’s a vast variety of tools out there, more than can be covered by me. Ask your neighbour what tools or libraries they use for data analysis

Key Points

---