************************************************
Solar Activity and Terrestrial Climate
(28 July 04) updated (30 July 04)
On July 6, 2004, a BBC article, headlined Sunspots reaching 1000-year high, caught the attention of a number of readers. Related articles soon appeared in other publications, for example: Suspot activity hits 1000-year high at Swissinfo.org, The truth about global warming - it's the Sun that's to blame at the London Telegraph, and Hotter-burning sun warming the planet at the Washington Times.
It seems that at a conference of astronomers in Hamburg, Germany, Sami Solanki and colleagues presented a discussion of possible correlations between solar variability and terrestrial climate. The recent articles provide some clues to the content of the presentation, but a slightly closer look may be of interest.
Interestingly enough, the principal paper on which the presentation was based was published last year, and briefly discussed here by John Daly at Evidence for an Unusually Active Sun. An abstract of the paper is available at Millennium-Scale Sunspot Number Reconstruction: Evidence for an Unusually Active Sun since the 1940s. The paper is available in PDF form at I.G. Usoskin, S. Solanki, M. Schuessler, K. Mursula, K. Alanko, A millennium scale sunspot number reconstruction: Evidence for an unusually active sun since the 1940's, Phys. Rev. Lett., 91(21), 211101, 2003. (Hereinafter, Usoskin et al. 2003)
Of several closely related papers I will mention I.G.Usoskin, K. Mursula, S. Solanki, M. Schuessler, and K. Alanko, Reconstruction of solar activity for the last millennium using 10Be data, Astron. Astrophys., 413, 745-751, 2004.. (Hereinafter, Usoskin et al. 2004)
Using records of 10Be (Beryllium 10) concentration in polar ice, and some physical models for processes connecting 10Be concentration with sunspot numbers, the authors attempt to reconstruct average sunspot numbers for the period from the year 850 to the present. Their reconstruction indicates that the period of high solar activity during the last 60 years is unique throughout the past 1150 years.
The 10Be records they use include annual data from Greenland for the years 1424 to 1985, and eight year sampled data from Antarctica for the years 850 to 1900. They supplement those data with some 14C (Carbon 14) data, apparently for most of the period of the study, and with group sunspot numbers (GSN) from 1610 on. While their methodology has its problems, they claim it results in a better correlation of 11 year smoothed "reconstructed" sunspot numbers with historical GSN than a statistical regression would do, and they summarize their results in a graph that includes indicators of MM: Medieval maximum, Om: Oort Minimum, Wm: Wolf minimum, Sm: Spörer minimum, Mm: Maunder minimum, and Dm: Dalton minimum. It also includes estimated corrections of their calculated sunspot numbers in the solid red and green lines.
In order for the sun to force the climate to the little ice age observed during the Maunder Minimum, the change in the solar constant had to be about twice what has been observed during modern, zero-sunspot periods.1. Modern zero-sunspot periods have been very brief. The most recent calendar month with a zero WSN was June 1913; the most recent calendar year with a zero WSN was 1810. A zero sunspot day, or week, may not tell us much about what the so-called solar constant would do during a zero sunspot year, or a zero sunspot decade.
In the 2002 Harold Jeffreys Lecture to the Royal Astronomical Society in London, Solanki said: After 1980, however, the Earth's temperature exhibits a remarkably steep rise, while the sun's irradiance displays at the most a weak secular trend. Hence the sun cannot be the dominant source of this latest temperature increase, with man-made greenhouse gases being the likely dominant alternative.1. That statement suggests that Solanki had not yet read Usoskin et al. 2003, which he co-authored. :-) Again, solar irradiance is not the only solar variable.
And it was timely too, because I just finished downloading a quarter million data points from the National Solar Radiation Data Base. They have been collecting data from 239 sites around the nation since before 1960. I've been analyzing the data on Excel and found something very interesting in their data. Over the last 30 years the amount of both direct and diffuse solar radiation reaching the earth, has declined about 10%.
Since solar radiation is the single biggest input to the climatologically algorithm, that's really a stunning 30 year change with major implications about climate change! This change is so large that I'm wondering whether the data they collected is real or whether the instrumentation was faulty or whether the data was "modeled" in some undisclosed manner. I've read both of the DOE manuals on how this data was collected and how it is applied, and I've found nothing that can explain so large a change.
--Boot Hill
Dang, boy, you don't just fool around!
If this is the same Danielle Murray, she and her gay lover contributed to global warming this past year.
http://www.bostonphoenix.com/boston/news_features/other_stories/multipage/documents/03849727.asp
Couples strolled through the line, hand in hand. Some indulged the spirited crowd by sharing passionate, wet kisses. Others held up their marriage-license applications triumphantly in the air. It felt like being a celebrity for a day, Danielle Murray admitted to me. She and her partner, Catherine Schaber, of Jamaica Plain, had waded through the throng, flushed and invigorated. The first hours of gay marriage in Massachusetts had far exceeded their expectations.
"Im so excited, Im shaking," said Murray.
"Its amazing," Schaber agreed.