Our Current Minimum is More Maunder than Dalton May 9, 2009
Posted by honestclimate in sunspots.Tags: climate change, Dalton Minimum, david archibald, global warming, Maunder Minimum, sunspots
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Our Current Minimum is More Maunder than Dalton
From Watts Up With That, May 8, 2009
Guest Post by David Archibald
This is a plot of three year windows on the Maunder and Dalton Minimum and the current minimum:
What it is showing is how the start of the current minimum compares with the starts of the Maunder and Dalton Minima. The solar cycle minimum at the start of the Dalton was a lot more active than the current one. If you consider that very small spots are being counted now, the activities are very similar. This is how they look without the Dalton:
If you consider the [current sunspot] counting problem, they are actually a pretty good match.
David Archibald
http://wattsupwiththat.com/2009/05/08/more-maunder-than-dalton
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Does shape of the preceding min offer a clue to the height of the next max?
The slowly forming bottoming shape of sunspot cycle 23 (copy from NOAA/SWPC pasted below) appears to have a somewhat hyperbolic shape (as though approaching zero asymptotically) rather than the usual, more parabolic shape that will be resumed after cycle 24 begins:
Using an enlarged version of the famous sunspot graph pasted below, I examined seven similarly shaped minimums from about 1750 to 1902, and the results are tabulated below the chart:
Following the slowly forming minimums that I identified approximately by date in Table A, the succeeding maximums were unusually low, as scaled approximately from the chart and identified in Table B:
Table A, Approx. Date of Min Table B, Approx Height of Following Max
_________________________ _________________________________
1755 < 85
1797 < 50
1810 < 50
1822 < 70
1878 < 60
1890 < 85
1902 < 60
I noticed that minimums exhibiting sharper bottoms appeared to be followed by much higher maximums and would invite comments, or a more exacting examination of this concept by anyone having better data than I was able to derive from my crude chart measurements.
Bob Paglee, P.E. (Ret.)
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In the end won’t the meridianal magnetic current or polar currents be the determining factor for how this minimum will evolve? If one or both hemispheres shut down…(currents idle) won’t that take a long time to get started given the size of the sun? Bill