Thursday, March 26, 2009

A claim was made by a certain person on the Christian forums that we are not having a longer than normal sunspot cycle. Clearly this gentleman doesn't know didly about the sunspot cycle. I have posted the number of sunspots per month, for the past 5 cycles. The x-axis is the number of months since the start of the cycle. You can see from the picture below, that Cycle 23, the one we are currently in, has not ended and that all other previous cycles, have, by this time in their cycle, moved on to the next cycle. Cycle 23 remains in place with cycle 24 refusing to start. Cycle 19 started in 1957 and clearly cycle 23 is a bit long in the tooth.




Now, I did not say that cycle 23 was a record. We have about a year to go in that department to match the longest cycles back in the early 1800s, right after the sunspot cycles had restarted after the Maunder minimum. But, this cycle is now is among the largest with spotless days, days where the sun has no spots.

http://users.telenet.be/j.janssens/Spotless/Spotless.html#Monthly

The above page was updated in January. Since then we have had over 60 more spotless days. and March looks to add even more.

Now, why is the sun not producing sunspots? An Australian astronomer, a solar scientist explains:

We propose that every 55 to 115 yr, the planetary driving
mechanism for the solar cycle experiences a phase
catastrophe that subdues the level of solar activity for
roughly one Hale cycle. The timing of the phase catastrophe
is a quasi-stochastic process that is loosely set by the
temporal phase difference between the length of the Hale
Cycle (?22.3 yr) and the synodic period of Jupiter and Saturn
(19.86 yr). The quasi-stochastic nature in the timing of
the phase catastrophe comes about simply because neither
of the two interacting cycles has a fixed length. The length
of the solar sunspot cycle can vary from 8.7 to 12.7 yr
(Usoskin&Marsula 2003), while the length of the synodic
period of Jupiter and Saturn can vary between 18.9 and
20.6 yr. However, on average, we expect the phase catastrophes
to reoccur roughly every 90 yr (? one Gleisberg
cycle).” I. R. G. WilsonA,, B. D. Carter, and I. A. Waite, “Does a Spin–Orbit Coupling Between the Sun and the Jovian
Planets Govern the Solar Cycle?,”
Publications of the Astronomical Society of Australia, 2008, 25, 85–93, p. 92

And he says that this hiatus will last for a while. Time will tell

“Interestingly, the Sun’s solar cycle has been in the phase
locked mode for the last 105 yr (1900–2005) and the
indications are that it is about to suffer another phase catastrophe
in the later part of cycle 24 (i.e. the solar cycle
that will peak in ?2011–2012). If this is the case, then
we should expect that in the two decades following the
phase catastrophe, the world’s mean temperature should
be noticeably cooler i.e. the cooling should start in the late
2010s. This claim is based on the precedent that there were
noticeable decreases in the world’s mean temperature following
the last two phase catastrophes. The cool period
know as the Dalton Minimum (1800–1820) that followed
the phase catastrophe in the early 1790s and a similar cool
period called the Victorian Minimum (1880–1900) that
followed the phase catastrophe in the late 1870s.”
I. R. G. WilsonA,, B. D. Carter, and I. A. Waite, “Does a Spin–Orbit Coupling Between the Sun and the Jovian
Planets Govern the Solar Cycle?,” Publications of the Astronomical Society of Australia, 2008, 25, 85–93, p. 93

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