Topband: K7RA's comment on Another Look at Sunspot minimum article
John Brosnahan -- W0UN
shr at swtexas.net
Fri Feb 15 11:42:35 EST 2008
At 06:04 15-02-08, w2pm at aol.com wrote:
>Here is Tad Cook's K7RA (ARRL Propagation guru) reaction to the article
>which K7FC posted here earlier in the week which suggested the
>possibility of a Maunder minimum - no sunspots for many years and a
>dramatic effect on the climate. --W2PM
> >From K7RA:
>There is no indication of a Maunder Minimum, absolutely none. There is
>nothing unusual about this solar minimum suggesting such a thing. And
>of course nobody can say there won't be one either.
With all due respect to W2PM, K7RA, and Ken Tapping there is
still some debate about the upcoming sunspot cycle. While not a
"Maunder Minimum", the debate is significant enough that the
NOAA Space Weather forecast included TWO different predictions
because the panel is very divided on their predictions.
With one prediction peaking at a sunspot number of 130 in late 2011,
and the other peaking at only about 80 in mid 2012.
NOAA considers this the only way to address the fact that the panel
could not converge on a single prediction as noted in their comment
that is dated NOV 6 2007.
>Ken is in Canada, and I am near the Canadian border, and we have both
>watched an excellent CBC program that suggests a source for this.
>Remember back when there were some "scientists" claiming there was no
>link between tobacco smoke and illness? They also cover that in this
>program. You can watch it on the web:
Pete implies that there are no "real scientists" who believe
in the link of global temperatures to solar radiation. But, in fact,
there are many top scientists who see the link between
solar activity and climate. Here is one link and I will be happy
to provide more off the reflector.
While Pete's link (denial machine) is about global warming and
may not be all that relevant to the Topband charter, it does raise
the issue of the source of global warming, since there is a much
better link of global temps to solar variability than there is to
anthropogenic CO2 production! The propagation on 160 reflects
solar activity but may also have some correlation to global temperatures!
According to my climatologist friends the best data set showing
the link between CO2 and temperature is the 50 years of Mauna Loa
CO2 data. But this data only has a 0.22 correlation with temperature
whereas this same data has a 0.74 correlation with solar variation.
Correlation does not imply causation (either from CO2 or solar
variability) but it is interesting that the correlation of temperature
to solar activity is more than THREE TIMES greater than that of
temperature to CO2.
There does appear to be a link between the length of a sunspot cycle
(and the length of the minimum) to the intensity of the following cycle.
And there are predictions that cycle 24 will be lower than cycle 23 and
that cycle 25 will be lower still.
There are many predictions of lower sunspot numbers for the upcoming
cycles (I only hope I get to live long enough to see how the predictions
pan out) and the following abstract is just to show one of the predictions
that suggest something on the order of the Maunder Minimum in Cycle 25.
On long-term variations of the total irradiance and on probable
changes of temperature in the Sun's core
Kinematika i Fizika Nebesnykh Tel, vol. 21, no. 6, p. 471-477
It is shown that the observable 11-year cyclic variation of the total
irradiance of the Sun is caused by respective alterations of the
radius and effective temperature of the photosphere, which are a
consequence of fundamental global processes occurring deeply inside.
The 11-year cyclic variation of "solar constant" almost entirely
results from respective alterations of the area of the photosphere
radiating surface as its effective temperature keeps practically
constant. Hence, 11-year heliocycle represents the simultaneous
coordinated fluctuation of the activity, radius and irradiance both
for the phase and amplitude. The century component is first directly
found in variations of "solar constant". We suppose that the
observable long-term identical variations of activity, radius and
irradiance are a result of the same processes occurring deeply inside
and are coordinated by a global variation of the entire Sun which is
caused by cyclic changes of temperature in the Sun's core. As this
takes place, the long-term global variations of the whole Sun can
serve the catalyst of the generation of solar cycles. We predict the
approach of the following sufficiently deep minimum of activity,
irradiance and radius of the 200-year cycle of the Sun near the year
2040+10. The minimum will be close to the level of the Maunder Minimum.
(I added the BOLD type to highlight the last two relevant sentences. --W0UN)
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