There is absolutely no doubt that QBO is forced by the lunisolar periods. By inspection and a first-order fit, the majority of the forcing is due to the draconic (aka nodal) lunar tide aliased with the seasonal stimulus. But if we then look at the residual, we see that a majority of the variability is due to the anomalistic lunar tide (i.e. the perigee/apogee lunar effect).
In the figure below, the upper panel is a power spectrum of the residual signal *after* incorporating the draconic tide. The ORANGE dots indicate where the power from the anomalistic aliased cycles should occur.
After applying that EXACTLY KNOWN period, the lower panel shows the next level of residual. As you can see, the overall power is greatly reduced by simply adding this one period.
The new set of dots shows where a possible nonlinear interaction between the lunar tides would occur. I didn't fit to that yet as it gets close to overfitting at that point. Classical tidal analysis proceeds in this manner, with literally hundreds of possible lunisolar (and planetary) periods contributing at lower significance levels.
The likely reason that this QBO deconstruction has never occurred is that scientists have looked at the power spectrum and couldn't make any sense of it. These aren't classical harmonics in the sense of a fundamental frequency and harmonics of that fundamental, but are in fact *aliased* harmonics that obey a different arithmetic progression.
That's why this AGW denier guy Richard Lindzen was completely stumped by the nature of the QBO for over 40 years. He couldn't figure it out even though he knew deep down that it could occur. These are the quotes by Lindzen that I presented at my AGU talk.
These are quotes from Lindzen's papers on QBO and atmospheric science topics from at least 30 years ago!
And consider that these are also statements from the guy that doesn't believe in AGW, and who currently sits on the GWPF board which has a charter to discredit the current climate science consensus. So this is the guy who will likely advise the WH in the next few years. :-B Time to drain the swamp and archive the data, because what is in store is not pretty unless we get in gear.