Last year I posted about Pier’s dramatic prediction for UK weather in May 2012. Piers’ method is based on motion of Sun and Moon and features a cycle of about 60 years. So when I saw a post by Bob Tisdale at WattsUpWithThat.com and also on his own blog about a pattern in sea level temperatures being repeated about 120 years later I took notice, 120 being 2 times 60.
You can watch Piers explain his ideas in more detail
And download the slides of Piers talk. On pages 12 to 16 of the slides Piers discusses a cycle of about 60 years in climate data.
The 2 Bob’s talk about a strong correlation in the NINO3.4 sea surface temperature record when comparing 1883 to 1899 v 2004 to 2013.
The periods being compared are 121 years apart, nearly 2 x 60.
Here is Bob Tisdales chart
In a different post Bob gives a link to the source of data
So I downloaded the data to see if I could reproduce the chart. Here are the tools I used, and here is my version of Bob’s graph. I found a correlation of 0.83.
I’m not quite sure why Bob plotted from 1883 to 1990, 17 years, as there are only 9 years from Jan 2004 to Dec 2012.
I also wondered if there was a correlation with somewhere around 1944, which would fit in with Piers approximate 60 year cycle. I found a correlation of 0.57 when comparing Jan 1943 to Dec 1951, not so strong as with 1883-1891 but still significant. If you doubt this download the data and try different periods, you’ll find the correlation soon drops away if you move one of the comparison periods just a few months.
Finding a 60 year cycle (approx) in climate data is nothing new. Hockeyschtick reported on a paper last year which found a 60 year cycle in sea levels, and Piers’ slides I mentioned earlier discuss various 60 year cycles.
As 60 year cycles can be explained in terms of the Sun and Moon it is nice to see there are indeed observed 60 year effects in temperature data.
Using correlations is not the usual way of looking for cycles, but it is something which is much more accessible to people with out a science/maths/engineering background. And the graphs of cycles can be understood by just about anyone.
My mum is nearly 90 and if I were to waffle on about fourier analysis she’d probably say something like
“Yes dear what would you like for tea? I’m just going out now so you’ll have to get your own“
But I reckon if I showed her the graphs and talked about repeating patterns caused by the movement of Sun and Moon she’d understand and might even be interested.
If you have a story to tell, surely it’s best to tell it in ways which mean as many people as possible can grasp?
And I nearly forgot to say.
With all this global warming and climate change going on it’s kind of hard to see how you would get nearly the same pattern in sea surface temperatures 121 years after 1883. Especially with the exponentially increasing world temperatures caused by the huge increase in human emissions of CO2.
You’d almost think that things are muddling along pretty much like they were over a century ago.