Brrr ... Cold winters in 17th century Europe, as shown in this painting by Hendrick Avercamp, may have been caused by a lack of solar activity after all.
Credit: Hendrick Avercamp/Wikimedia Commons
Posted on 05/26/2011 1:50:30 PM PDT by neverdem
BOSTON—For decades, astronomers and climatologists have debated whether a prolonged 17th century cold spell, best documented in Europe, could have been caused by erratic behavior of the sun. Now, an American solar physicist says he has new evidence to suggest that the sun was indeed the culprit.
The sun isn’t as constant as it appears. Instead, its surface is regularly beset by storms of swirling magnetic fields. As a result, like a teenager plagued with acne, the face of the sun often sprouts relatively dark and short-lived “sunspots,” which appear when strong magnetic fields inhibit the upwelling of hotter gas from below. The number of those spots waxes and wanes regularly in an 11-year cycle. However, even that cycle isn’t immutable.
In 1893, English astronomer Edward Maunder, studying historical records, noted that the cycle essentially stopped between 1645 and 1715. Instead, the sun was almost devoid of sunspots during this period. In 1976, American solar physicist John “Jack” Eddy suggested there might have been a causal link between this “Maunder Minimum” in the number of sunspots and the contemporaneous Little Ice Age, when average temperatures in Europe were a degree centigrade lower than normal.
One might expect the absence of dark spots to make the sun slightly brighter and hotter. But the absence of other signs of magnetic activity, such as bright patches of very hot gas known as faculae more than compensates for this effect. So in fact, the total energy output of the sun is lower during a solar minimum. If the minimum is prolonged, as it was in the second half of the 17th century, the dip in output might indeed affect Earth’s climate.
However, scientists have debated whether the effect could have been large enough. For instance, in a recent paper in Geophysical Research Letters, solar physicist Karel Schrijver of the Lockheed Martin Advanced Technology Center in Palo Alto, California, and his colleagues argue that during the Maunder Minimum, the sun couldn’t have dimmed enough to explain the Little Ice Age. Even during a prolonged minimum, they claim, an extensive network of very small faculae on the sun’s hot surface remains to keep the energy output above a certain threshold level.
Not so, says Peter Foukal, an independent solar physicist with Heliophysics Inc. in Nahant, Massachusetts, who contends that Schrijver and his colleagues are “assuming an answer” in a circular argument. According to Foukal, who presented his work yesterday here at the summer meeting of the American Astronomical Society, there is no reason to believe that the network of small faculae would persist during long periods of solar quiescence. In fact, he says, observations between 2007 and 2009, when the sun was spotless for an unusually long time, reveal that all forms of magnetic activity diminished, including the small-faculae network.
What’s more, detailed observations from orbiting solar telescopes have shown that the small faculae pump out more energy per unit surface area than the larger ones already known to disappear along with the sunspots. So if the small faculae start to fade, too, that would have an even stronger effect on the total energy production of the sun. “There’s tantalizing evidence that [during the Maunder Minimum] the sun may have actually dimmed more than we have thought until now,” Foukal says.
Even so, Foukal concedes that other factors, such as enhanced volcanic activity around the globe, may also have played a role in causing Europe’s Little Ice Age. Meanwhile, the biggest worry to solar physicists—and to society—is that no one knows what caused the sun’s prolonged quiescence in the first place. As far as anybody knows, a repeat of the Maunder Minimum could start within a few years with the next dip in the number of sunspots.
Decrease solar activity was the cause as has been known for decades. Many decades.
Who would believe that the changes in the giant ball of thermonuclear fusion that supplies all of earth’s energy would have anything to do with the climate?
;-)
the sun doesn’t keep us warm! dirty factories, burning oil and cow farts create the heat in the atmosphere. duh.
Exactly. God help us if sunspot activity goes through another inactive period and we experience REAL "climate change." Huge increases in energy bills, significant decreases in farmable land. Starvation, death and perhaps war in Third World countries. And as the article says, we have absolutely no control over it if it starts happening again. Vanity, thy name is Man.
I really liked the movie. Wonder what happened to the little fellows nut??? Oh, I missed the real one!
Bush’s fault.
We’re just too dumb to understand. The idea that the sun affects our temperature is so primitive.
How about above normal tectonic activity, aka, earthquakes, in shaking up the planet just a teenie little bit, enough to shake it's rotation off by maybe just a degree or two.......
Think that's possible?
The question begging to be asked is, "Why should that be a worry?" There is absolutely nothing mankind can do to change the sun's activity. ... Except, perhaps, to send money to Algore.
Imagine that, the sun having something to do with climate. It’s amazing.
And increased solar activity would warm the earth - go figure.
Ok, I understand your point about volcanoes. But this mini-Ice Age actually started around 1300 ad. See: The Little Ice Age, by Brian Fagan.
“no one knows what caused the sun’s prolonged quiescence in the first place.”
Some Russian scientists have crunched the numbers about the orbit of Jupiter, the Sun, the center of mass of the solar system, etc., and have come up with some pretty good correlations. (If I have the time, I’ll try to dig up a link.)
The bad news? According to them, we’re in the start of another doozie of a minimum...
Lots of other stuff happened.
Settlement of the Americas was NOT HIGH ON THE AGENDA ~ may well be big in our minds (my ancestors did it ~ fled that pestilential hellhole for the malarial backwaters of the East Coast in fact), but for the most part this was a place the Brits dumped POWs. I presume the Spanish continued with the practice as well.
The slave trade was roaring big time ~ mostly because Europeans and Indians were pretty much NOT immune to malaria. Sickle cell anemia conferred immunity on those with one gene.
Let me tell you how horrid the Americas were in that period ~ you can read 100% of every document written here in Spanish or English areas in a few days ~ there are several libraries with copies of all of it ~ either in microfiche or digital format. I think I've read most of it too.
American settlement efforts rose substantially AFTER the Maunder Minimum, and China began a period of turmoil that's only now settling down.
You could have had massive volcanism and those guys wouldn't have noticed it.
Several years ago...on NPR’s Science Friday...they had a global warmer doing his Q&A. So a caller asked....what was the effect of the sun on climate, and the answer was “marginal if any”. I pulled up the NPR site...looked at the guy’s name...did a Google search....and found his entire bio (in particular, his degree). I went to the university site and then looked at what it would take to get a Earth Sciences degree from this university. Amazingly enough....there are no solar science or universal topic classes required...for either the bachelors or master’s degree.
So in effect....the guy likely knows nothing about solar science and just didn’t want to admit that. When any global warmer tells you some fact relating to the sun...ask them to explain solar winds in detail, and sun spots. If they can’t answer either...they don’t know much related to the sun. End of the story.
Fact is, you burn carbon, you get heat, QED
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