[outofsalt]

If we assume that the temperature records correlate with sunspot intensity, we can in rough terms assume that the 180-year cycle dominated from about 1100 to 1450 and the 220-year cycle dominates from 1650 to 2100. Stuiver-Brazuiunas analysis (ch. 7.4) also indicates this possibility. The previous 1000 years look like a mirror from this. The 2*180 year period seems to begin and end with a warm period and the 2*220 year period seems to begin and end with a cold period. The length of this period is one Gleissberg. The next cold period should begin about 2020. http://personal.inet.fi/tiede/tilmari/sunspot8.html#hyps2289

[Robert A Cook PE]

Very interesting relationship being proposed now between the gravitational pull (center of gravity) of the 4 Jovian planets vs sunspot nbr/solar intensity/solar magnetic fields, and the Pacific Oscillations (PDO) and North Atlantic Oscillation patterns.

Over the long term (1600 - 2008) these short cycle periods (40 year cycle) solar oscillations track very close to the PDO and North Atlantic changes. Not quite as closely to temperatures directly, but the the changes in currents (El Nino/La Nina) follows the same cycle start-stop times.