Watts Up With That? ^{[1]}

Thursday, Dec 3rd, 2009

With Climategate sucking all the oxygen out of the blogosphere, we’ve neglected some of our regular reporting duties here at WUWT.

Thanks to Paul Stanko, who has been tracking sunspots for WUWT for awhile now who writes in with this update. It looks like we’ll soon surpass 2008 for the number of spotless days. – Anthony

**Guest post by Paul Stanko**

With November now in the past, I’ve got a fresh set of statistics, and it looks like this cycle is falling ever further into an even deeper funk. The attached graphics are revamped according to Leif’s impromptu peer review and I believe are

much improved. They are a few days old, though.

The 2009 spotless days are now 262 and the cycle 24 spotless days are now 774. On the cycle graph, I now calculated three different sets of spotless days per cycle. Minimum just counted the actual observed and reported days of zero sunspots. Maximum assumed that all missing obs were zero sunspot days. Likely assigned spotless days to the missing obs in the same ratio as the reported obs for that year.

The graphs were reporting what I now call Minimum. They now report Likely, hence the increase in values for some of the older cycles. There is a second number now too, a % confidence. I calculated this by the following formula: 100% * (1 -((Maximum – Minimum) / Likely)). When all obs are reported, Maximum = Minimum = Likely so this becomes 100%.

Any cycle where the confidence is 0% means I gave it my level best estimate, but anybody else’s estimate is more than likely just as good.

Comparing the actual months to the updated prediction gives some interesting insights once again… all numbers are SIDC 13 month smoothed… the predicted peak is 90, which I use to estimate suggested peak…

Jan 2009 had 2.1 for a prediction, 1.71 actual. Suggested peak = 73.16

(18.71% low)

Feb 2009 had 2.7 for a prediction, 1.67 actual. Suggested peak = 55.62

(38.20% low)

Mar 2009 had 3.3 for a prediction, 1.97 actual. Suggested peak = 53.83

(40.19% low)

Apr 2009 had 3.9 for a prediction, 2.24 actual. Suggested peak = 51.79

(42.46% low)

May 2009 had 4.6 for a prediction, 2.36 actual. Suggested peak = 46.16

(48.71% low)

Jun 2009 had 5.5 for a prediction, but requires December data for actual

numbers.

To put these into context, I looked at the 13 month smoothed peaks of all the numbered cycles. 80, as well as 90, would be the weakest cycle since 1933.

66 to 75, which includes Leif’s prediction of 72, would be the weakest cycle since 1913. 50 to 65, which includes my prediction of 60, would be the weakest cycle

since 1823. 49 would be the weakest cycle since 1810. 48 or less, which includes Dr. Archibald’s prediction of 42 (and my May 2009 update) would be the weakest cycle since the Maunder Minimum.

Also, keeping in mind the current cycle has 774 spotless days racked up

already…

The mean number of spotless days excluding both Dalton and Maunder

minima is 557, with a standard deviation of 258. We are almost 1 sigma above the mean. The mean number of spotless days including the Dalton but excluding the

Maunder is 777, which we have the potential to reach in just a few days, with a

sigma of 578.

Listing the weakest numbered cycles by month is also interesting…

The values for the first 4 months of cycle 6 were 0.00, 0.00, 0.00 and

0.00. (Dalton minimum)

The values for the first 4 months of cycle 7 were 0.08, 1.65, 3.32 and 4.15

The values for the first 4 months of cycle 12 were 2.41, 2.58, 2.50 and 2.58

The values for the first 4 months of cycle 15 were 1.55, 1.57, 1.58 and 2.88

and the values for the first 4 months of cycle 24 were 1.67, 1.97, 2.24

and 2.36.

So, it seems the only solar cycle which rose even slower than this one was cycle 6.

Hope you and your readers find this interesting,