People send me stuff.
Tonight I got an email that contained a link to a paper that takes on the wonky claims related to barycentrism and Earth’s climate, specifically as it relates to Nicola Scafetta’s 2010 and 2012 papers. This new paper taking on the Scafetta claims will be published in the Journal of Atmospheric and Solar-Terrestrial Physics, April 2014. The author is Sverre Holm Department of Informatics, University of Oslo, Norway.
Abstract, some graphs, and discussion/conclusion, along with a link to the paper follows.
It has recently been claimed that there is significant coherence between the spectral peaks of the global temperature series over the last 160 years and those of the speed of the solar center of mass at periods of 10-10.5, 20-21, 30 and 60-62 years. Here it is shown that these claims are based on a comparison between spectral peaks in spectral estimates that assume that the global temperature data contains time-invariant spectral lines. However, time–frequency analysis using both windowed periodograms and the maximum entropy method shows that this is not the case. An estimate of the magnitude squared coherence shows instead that under certain conditions only coherence at a period of 15-17 years can be found in the data. As this result builds on a low number of independent averages and also is unwarranted from any physical model it is doubtful whether it is significant.
Discussion and Conclusion
Scafetta (2010) claimed the global temperature series for the last 160 years to have
spectral lines at 21, 30 and 62 years. Time–frequency analysis shows that the lines are
time-varying (Figs. 1 and 2) and very different from the nearly constant lines in the
time–frequency plot for the speed of the center of mass of the solar system (SCMSS)
The supposed periodicity around 30 years in Scafetta (2010) is not really
present in the climate series at all and could be an artifact due to a combination
of model overfitting and smearing due to the time-invariance assumption which has
been forced on the data. The claimed spectral peaks by Scafetta (2010) for the global
temperature series are therefore not reproducible if proper consideration is taken of
the time-varying nature of the data. The only significant coherence between the cli-
mate series and the sun’s movement that was possible to find was at 15-17 years (Table 1). However, both the low number of independent averages that it builds on as well as the lack of a physical explanation for this coherence, makes us hesitate to claim that it is significant.
Looks to me like “game over” for claims of Barycentrism controlling Earth’s climate. Clearly this was a case of pulling a signal from noise that is just an artifact of the process, much like Mann’s special brand of math that made hockey sticks from just about any red noise input data.
Full pre-print of the paper here: http://arxiv.org/pdf/1307.1086.pdf