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Old February 16th 16, 10:14 PM posted to uk.sci.weather
Lawrence Jenkins Lawrence Jenkins is offline
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Default Solar Cycles and *possible* Dalton-type to come?

On Tuesday, 16 February 2016 22:58:27 UTC, Martin Brown wrote:
On 16/02/2016 21:21, JCW wrote:
Had a quick read of this, understood very little of it, but of course caught the last few lines which read:

"The first of these oscillations may even turn out to be as strongly negative as around 1810,
in which case a short Grand Minimum similar to the Dalton one might

develop.
This moderate-to-low-activity episode is expected to last for at

least one Gleissberg cycle (60-100 years)."

Note the use of the word "may". On the face of it this recent cycle 24
is quiet for what should have been a solar maximum but it is more like
those of 1928, 1908 or 1884. Here is the Zurich sunspot number graph:

http://solarscience.msfc.nasa.gov/im...olor_Small.jpg

OTOH the last five cycles three have been strong by historical standards
(and a part of that has been traced to a calibration error due to a
change in counting methods).

The remaining extract he

http://www.sciencedirect.com/science...64682608003787

This should give rise to further discussion / analysis by those with interest
and knowledge of cycles and their possible or potential impact on

weather?

There certainly could be some effect since a highly active sun can fluff
up the outer atmosphere and increases drag on satellites. It is also
very slightly brighter by 0.1% when active despite having dark sunspots
it also has bright faculae which occupy a much larger area.

A Dalton minimum-type possibility, eh?

There is always a slight possibility of anything.

There is some evidence that the solar dynamo is weakening and if it
drops below a certain threshold then sunspots will become rarer.

--
Regards,
Martin Brown


The sceptics have been going on about the weak solar 24 for ten years