The big news we’ve all been tracking this summer and fall, of course, is the disconcerting lack of sunspots. This is correlated BTW with a dramatic drop in solar wind pressure.
But now it looks like Cycle 24 might finally be starting:
http://science.nasa.gov/headlines/y2008/07nov_signsoflife.htm
A concern has nagged the climatology community that the fluctuation in solar activity represented by Cycle 23 has contributed to the muting of the global warming signal, at least relative to the GCMs employed by the modelers. It will be interesting to see if Cycle 24 does continue the recent trend of less active solar disturbances, and whether there is a correlation with cooler climatology on Earth. As always, correlation is not causation — but it’s food for thought and model fodder.
It might also be informative to hear the perspective from our Arctic Circle friends, who actually know something about solar physics. And about ice.
UPDATE: Nice big sunspot image from 12 Nov 2008 located here.
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Thursday, 20 November 2008 at 17:22
It seems sunspots, or the lack of them, pervades almost every aspect of my life. As a shortwave and ham radio enthusiast for the past four decades, I’ve been through a fair share of solar cycles and experienced the results first hand. As an aurora groupie with a front row seat for the past ten years, I’ve endured almost one complete solar cycle in the subzero winter nights. I am also an engineer involved in environmental satellite operations, not the least of which is the collection of space weather information.
The frustrating, extended delay of Cycle 24 is unmistakable to me. I have observed only brief, infrequent auroral displays for the past four years. (Compare this with northern lights so bright they would wake me in the night.) Poor high-frequency radio propagation from the arctic latitudes is another manifestation. In a good solar peak, one can literally talk to the world with 5 watts and a short length of wire. Large antennas and high power from Fairbanks have had only limited success lately. (I have to concede there are occasional signs of improving radio conditions in the past couple of months.)
Weather-wise in Interior Alaska, there’s been a strong correlation with milder winters and the lower solar activity of the past five years. We have had many more cloudy nights in winter than in the first five years of living here. Temperatures typically range from -20F to +20F, and we’ve avoided long cold snaps of 50 below or less. Strong Pineapple Express upper level winds have even brought freezing rain in December and January. Summers have been hotter and drier with 2007 even having thunderstorms into October. Usually, we have few thunderstorms after mid-August. Interestingly, summer 2008 proved to be unusually cool and rainy with many fewer thunderstorms than normal. The results in many failed gardens but a record low for wildfire burns.
Ice-wise, my scientist friends and colleagues willing to share thoughts are scratching their heads. I was at a meeting in August 2007 where a respected scientist showed the astonishing results of multi-year ice disappearance over the North Pole. He announced the consensus of his colleagues was the earth had possibly reached a tipping point, and it would only get worse in 2008. This year, decrease of sea-ice extent proved a bit less dramatic than 2007 but still more notable than, say, 2003.
The only ones I know truly happy about all the uncertainty of Cycle 24 are the solar scientists. They have many new tools, including a bevy of geo- and helio-centric satellites, monitoring the sun and space environmental conditions. Coordinated research projects tying earth-based sensors to space observations have developed some very interesting explanations for previously misunderstood phenomena. My friends in Boulder at the Space Weather Prediction Center are almost giddy.
Now, if we could just get these guys and gals talking to the climatologists, we might actually get somewhere.
Friday, 21 November 2008 at 05:40
Speaking of the sun, AP has something cool to report:
WARSAW, Poland – Researchers said Thursday they have identified the remains of Nicolaus Copernicus by comparing DNA from a skeleton and hair retrieved from one of the 16th-century astronomer’s books. The findings could put an end to centuries of speculation about the exact resting spot of Copernicus, a priest and astronomer whose theories identified the Sun, not the Earth, as the center of the universe.
Polish archaeologist Jerzy Gassowski told a news conference that forensic facial reconstruction of the skull, missing the lower jaw, his team found in 2005 buried in a Roman Catholic Cathedral in Frombork, Poland, bears striking resemblance to existing portraits of Copernicus.
Also check out http://dsc.discovery.com/news/2008/11/20/copernicus-tomb-02.html
Monday, 24 November 2008 at 15:52
Fascinating. Your comment about cloud cover caught my attention. One of the frequently-voiced criticisms of the ’standard model’ of global warming is that there are significant gaps in our understanding of the role of cloud cover in global climate. One article I read recently asserted that the uncertainty in cloud forcing swamped the signal for AGW. Another researcher concluded that the historical record of influence of the solar cycle on cloud formation was muddied because of confounding variables — in particular, the response of cloud cover to solar wind was positive in years with little volcanic activity and negative in years with substantial volcanic activity. Your comment makes me suspect that increased cloud cover can decrease temperatures in mid-latitudes while increasing them in high latitudes — which again raises questions about the wisdom of forcing climate change into the template of a single-variable response (’global temperature’). Food for thought.
Wednesday, 26 November 2008 at 01:14
I’m inclined to think the focus on global temperature is bogus. Why not the median global wind speed (or something equally arbitrary)? Wouldn’t some measure of the “potential” and “kinetic” energies of the entire earth ecosystem be a better measure of trends? Temperature is just one manifestation of said energies, which may be offset somewhere else; e.g., energy stored or released in biological systems.
Thursday, 22 January 2009 at 08:05
Is there a link between Earth’s magnetic field and low-latitude precipitation? “Our results show a strong correlation between the strength of the Earth’s magnetic field and the amount of precipitation in the tropics,” one of the two Danish geophysicists behind the study, Mads Faurschou Knudsen of the geology department at Aarhus University in western Denmark, told the Videnskab journal. Link to abstract is here http://geology.geoscienceworld.org/cgi/content/abstract/37/1/71