Thursday, March 27, 2014

What causes the natural 60-year climate cycle? A new theory

From a comment by Bart, elevated to a post:

What is the cause of the ~60 year quasi-cycle? I noticed this just a little while ago.

The Earth's rotation axis is nutating with a period of about 18.6 years. However, that is only part of the story. In actual fact, the nutation takes the form of an elliptical cone, as shown here:

The distance between the J2000 polar axis and the actual rotation axis looks like this. Its period is necessarily halved, to about 9.3 years:

Thus, the magnitude of the component of the magnetic moment of the Sun along the Earth's rotation axis should have periods of about

T1 = 11*9.3/(11+9.3) = 5 years

T2 = 11*9.3/(11-9.3) = 60 years

Coincidence? Maybe. But, is there not a 5-ish year quasi-periodicity to the major temperature sets? Hard to say for sure, but there surely are several ups and downs which are in the neighborhood of 5 years:


Thanks Bart, I would add that a Fourier analysis does suggest a 5 year periodicity of the HADCRU surface temperature dataset, as well as the well-known 60 year climate cycle:

Several papers relating the 60 year climate cycle to solar activity, ocean oscillations [which are in-turn driven by solar activity], and lunar-tidal cycles:

60-year periodicity in the PDO during the instrument era (first graph) and from paleoclimate reconstructions (second graph).

Pacific sea surface temperatures also show a periodicity of ~60 years in this wavelet analysis

1 comment:

  1. Thanks for the additional info. I don't think I'd elevate this to a "theory" as yet, though. Maybe an hypothesis, or even just something to mull over and consider. -Bart