Guest Post by Willis Eschenbach I’ve developed a curious kind of algorithm that I’ve humorously called “slow Fourier analysis”, but which might be better described as a method for direct spectral analysis. The basic concept is quite simple. I fit a sine wave with a certain cycle length, say 19 months, to the dataset of…
Guest Post by Willis Eschenbach A look at Gleissberg’s famous solar cycle reveals that it is constructed from some dubious signal analysis methods. This purported 80-year “Gleissberg cycle” in the sunspot numbers has excited much interest since Gleissberg’s original work. However, the claimed length of the cycle has varied widely.
The sunspot number for February from SIDC is down again, to 33.1 Here’s the source of that data: http://sidc.oma.be/DATA/monthssn.dat So far, cycle 24 is significantly lower in SSN number that the last three cycles, in addition to having a delayed start. While the delta of the drop in Feb 2012 is not unusual by itself,…