Sunspot Update – February 2009
Posted by The Diatribe Guy on February 9, 2009
UPDATE:I would like to point out a comment (#4) by Tad Cook below. I am indebted to his helpful explanation on the nature of the determination of sunspot counts by month in the NOAA data set. With his explanation, take my presentation below in the spirit of a presentation of the data from a table where the last six months are preliminary estimates. In the future, when referencing that data, I will try and be sure to acknowledge that. Mr. Cook has, apparently, been digging into the daily sunspot numbers and believes that the actual January number will be around 3.2 when the final numbers are determined.
What I find interesting is that we hear all sorts of different opinions as to what, if anything, this all means to us. I find the sunspot cycles fascinating from a cycles/data perspective. I have done some correlation analysis that seems to imply that the length of the cycle matters. However, there are limitations to that analysis because it does not remove the effects of other major variables, so until I do a more thorough job on that it is simply a curiosity. There is this paper that implies the same thing, though, in stating that length of the cycle is inversely related to temperature. I have shown the collapsed charts that consider both magnitude and length in recent decades. I have summarized two papers by John A. Eddy here and here that seems to make the case for solar minimums driving temperature downward. Overall, the Landscheidt papers certainly focus on correlations of solar and planetary activity in conjunction with climate. Some feel that focusing on cyclical movements of planets and the sun becomes too astrological. I disagree with that assessment, but the criticism is out there.
But those aren’t the only opinions. If you frequent Watts Up With That? you will be familiar with a frequent commenter/contributor by the name of Leif Svalgaard. Leif, as far as I can tell, is a reasonable fellow who is interested in the science of the sun, and not particularly concerned with advancing one agenda over another. I have seen him equally berate the way NOAA uses the information as well as those who he feels makes equally inastute predictions/observations of the meaning of what the sun is currently doing. He has extensive work here which I admit to not spending as much time on as I’d like. I have, however, kept an eye on many interesting charts he has put together in this source. I mention Leif as an example of someone who I think has the right attitude and motivations regarding the science, but who does not embrace the correlation between sunspot cycles and climate like many others do. Agree or disagree with him, I don’t see any agenda with his opinion. He has scientific bases for having reached that conclusion. He is also not a fan of many of Landscheidt’s methods.
So, basically, we don’t know a whole lot. We have correlations of past events, and different and improving instruments to assess all aspects of the sun. But we don’t necessarily know a lot.
What we do have, nonetheless, is sunspot data. And whether you think the sun tells us little aboout climate or whether you think we’re heading into another ice age, the data is fascinating.
The January sunspot number was another extremely low value (1.5). Once again, this drove down the averages we see. It also lengthened the current cycle (as measured from 12-month average minimum value to 12-month average minimum) to 148 months. It was already longer than the previous 13 cycles, and this status continues. If this cycle lengthens by 2 more months (which is possible – February 2008 was pretty low [2.1] but March 2008 had a count of 9.3), it will become longer than the previous 17 cycles, and we will only know about 2 other cycles that were longer.
As for observed averages, the 12-month, 24-month, and 36-month average sunspot numbers are all the lowest values since 1914, 1914, and 1915 respectively. The 48, 60, 72, and 84 month averages are lowest since 1935, 1936, 1936, and 1937 respectively. The 96, 108, and 120 month averages are the lowest since 1979, and the 132 and 144 month averages are the lowest since 1946.
For those who prefer charts, here are a few: