Sea Surface Temperatures – I



Stage I – Status report, December 2014
Originally in Climate – A personal Perspective


Planetary cycles model of southern hemisphere sea surface temperature
SST data from NOAA. Model and parameters are shown in inset.

The model plot presents the results of a few hours I spent with a spreadsheet and a model of solar irradiance published by Nicola Scafetta – adapting it to fit southern sea surface temperature data. The SST data set was chosen because of the relative simplicity and regularity of southern climate zones, the predominance of oceans in the south, and because oceans are the primary driver of the Earth's water thermostat. If the Earth's climates have a heartbeat it's to be found in the oceans. Also, as discussed earlier, I can't see the continental meteorological data as reliable.

This model is based on planetary cycles but not all cycle based models are. An Australian scientist, David Evans, drew on the sophisticated mathematical toolkit developed by electrical engineers over the last century and from this generalised perspective he came up with similar results, and clues to the role of ocean cycles on the influence of the sun's decadal cycle. I've not presented my little effort as an optimal fit, or an endpoint in my dabbling, but to illustrate the downward future extrapolation shown by all such models that I've seen. The trend seems robust and recent cold winters in the north, and expanding sea ice at the poles, may herald its start.

Projecting this model backward and forward in time shows the peak of the current millennial maximum to be around the year 2000 with 3.5C between millennial extremes. The model is clearly not the full picture. For a start, historically, the millennial peaks seem to be decreasing. Greenland is not as warm as it was when the Vikings settled and, as far as I know, nobody has emulated the achievement of the Romans in growing vineyards near Hadrian's Wall. The decadal cycle varies in length and amplitude so it is likely that the longer cycles do too. There are many planetary cycles and the sun's internal dynamics will be subject to its own constraints.

In as far as this model still has free parameters not yet tied to physical measurements it's still, to some degree, a curve fitting exercise and, as noted above for the IPCC models, extrapolation should be treated with caution. Since the cycle frequencies and phases can be related to solar irradiance measurements and known planetary cycles this small parameter set is not as arbitrary as hundreds of parameters used in the IPCC models. The principle of parsimony puts cyclic models well ahead. They are also better at matching the details of past data where the IPCC models fail – as their failure to predict the present temperature plateau demonstrates. When a simple spreadsheet model can outperform supercomputer calculations that can take months to run, something is fundamentally wrong. The IPCC is lost in a complexity jungle of its own creation. 

The solar cycle models are tapping fundamental planetary dynamics. The precise harmonic relationships between the orbital motions of the planets and the parallel these have with musical scales has been known for centuries. Here we see the southern oceans dancing to the music of the spheres.