What is NCO and why should I use it?
The netCDF Operators (NCO) is a group of programs that allows you to manipulate netCDF files. You can edit file attributes, rename variables, extract variables for certain dimensions (such as a given time slice or geographical area), and create ensembles and averages. You can do much of the same things with NCL, but NCO is much easier to use. The commands are given at the unix command prompt, or they can be strung together in a shell script, depending on the amount of manipulation that needs to be done (see official documentation for NCO). We've put together some examples here using some CCR files. In all cases, the original data file is available for download.
How to use NCO and these examples: first, make a back-up copy of any files you wish to process. NCO will usually give you an error message if something goes wrong, but it's always best to have a copy of your unaltered data.