The well known phase drift of SSN solar cycles against sea surface temperature is illustrated.
The annotated peaks in SST show a mean period of 9.12 years, a figure that has been noted by serveral researchers in a variety of natural phenomana and identified by Nicola Scaffeta as being of lunar origin.
The first date annotated here falls in the very unreliable and highly ‘bais corrected’ WWII period. Using only the more reliable, post-war data gives a figure of 8.84 years. This is very close to the period of precession of the lunar apsides ( the orientation of the eccentricity of the lunar orbit that determines latitude on Earth over which the maximum tidal forces at perigee occur).
This improved calculation is shown here:
The two seem to be close to being in phase around 1960 and in antiphase in 1925 and 1995.