For anybody who want to get nearer the road than any of us are in this algorithm chucking game (which I think possibly everybody is forced to play, given the complexity), there is this [CSEOF Fortran](http://www.cgd.ucar.edu/cas/software/SUBR_CYCLOSTATIONARY_WD.f90.html) code (apparently derived from that used by Kim et al.).
I don't have the mileage to download the datasets so I'm not trying it :).
Anyway I just ground my way through the just so, convoluted text of this paper trying to extract any strong statements I could. I wanted to compare its description of El Nino and techniques with Ian Ross's description which is among the clearest I've come across. I always start trying to substitute the greek squiggles with v. bad pseudocode due to bad maths fu.
My notes should be [here](https://dl.dropboxusercontent.com/u/61621163/Docs/QBOKim.md)