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.
[EDIT]
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.
climategrog 
