5X5 Episode 35

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5X5 Episode 35
No sunspots in August - will this lead to a period of solar cooling?
3th September 2008
5X5 34	5X5 36
Skeptical Rogues
S: Steven Novella
R: Rebecca Watson
B: Bob Novella
E: Evan Bernstein
Guest
PG: Pamela Gay
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Show Notes
Forum Topic

No sunspots in August - will this lead to a period of solar cooling?

Voice-over: You're listening to the Skeptics' Guide 5x5, five minutes with five skeptics, with Steve, Jay, Rebecca, Bob and Evan.

S: This is the SGU 5x5 and tonight's topic is sunspots. We are joined for this podcast by Pamela Gay from Astronomy Cast. Pamela, thank you for joining us

PG: Oh, thanks for inviting me.

S: So we are just coming out of our solar minimum, meaning the 11 year cycle of the sunspots; and the month of August had no recorded sunspots and this is the first time that has happened in almost a century.

PG: Yeaaaaaah... This is one of the problems. The sun is a star and stars are Intemperate objects. Even Shakespeare acknowledge them as being in constant ..., our sun has a magnetic field that likes to flip itself inside-out every, oh, 11 years or so, and in the middle of the flip it is busy and coated in sunspots but once it has its fields aligned, it tends to have very few sunspots on the surface. The sunspots are just places where the magnetic field lines stick themselves out, and go back in. Our sun seems to have a nice happy magnetic field right now that isn't interested in turning itself back inside-out. One month isn't all that long to worry, it's if this keeps going and keeps going that we start to be concerned. And that has happened before.

R: What's all this about an ice age?

PG: (laughing) Well

R: I'm being frightened.

PG: Well, you shouldn't be, at least not yet. Especially with global warming. Back from 1645-1715 there was what we call the Maunder minimum. This is a period in time when there were very few sunspots recorded. Under 10 per decade basically during that period. And it just happened to coincide with a mini ice age where for various reasons the northern hemisphere, specifically Europe, was much, much colder during the winter than it normally was, although recorded temperatures show that .. or at least recorded estimates of temperature based on what the people reported, say that during summer it was just fine, so it seems to be that with a lack of magnetic activity from the sun, the jet-stream decided to move itself too far south during the winter and so Europe got more cold than really was comfortable for anyone.

S: What do you think about the theory that the sun's magnetic field helps protect the Earth from cosmic rays? So with a more stable or decreased magnetic field there is more cosmic rays which increases the cloud formation on the Earth which then reduces the temperature by blocking out more of the sun that was causally related to the mini-ice age.

PG: I think it is a complicated process, we're still trying to figure things out. Magnetic fields are one of the most complicated things for any astronomer, or physicist to work with, and the Earth has its own magnetic field, and what we don't know is what were the temperature gradients on the planet? What were, what was the rate of ice falling into the North Atlantic? Other things can effect a lot of this, just by introducing more fresh water into the sea you can change all sorts of things. The, what was the Earth's magnetic field doing? The sun's magnetic field definitely did have something to do with it. Saying any one thing in particular is difficult. There is also evidence that there is a lot more volcanism going on in the period, so we are trying to decouple too many different things to say that any one thing caused, for instance, cloud cover. Clouds could just as easily have come from having extra volcanic ash in the air. There's too many different things to uncouple.

E: Yeah, according to this article, it says that this could possibly also be effecting things such as: wavelengths in the far ultra-violet, effecting ozone production, and natural production of isotopes such as ¹⁴C which apparently might also be tied to the solar activity.

B: Yeah, just for comparison, when things are running normally, when the sun is active, we might see a hundred or more sun-spots in a given month, and at the other end of the spectrum, normally when the sun is very inactive, it briefly drop to near zero and then quickly the sunspots will return as a new cycle begins. That's what we usually see.

S: But this year it's been like, less than three per month, and again August has seen zero spots by some observers and I think like a half a point or a half a spot by some other observers, but essentially no sunspot activity, and it's again just a little bit longer than normal, or average we should say, and just really I guess, it will depend on how long this is going to last, but one of the interesting things is the potential irony of the solar forcing of the climate perhaps now moving in a direction that might counter balance human forcing through man-made greenhouse gasses and global warming. Wouldn't it be ironic if the man-made contribution ended up helping stabilize our climate because we just happen to be going through a solar period of cooling.

E: That would be the ultimate irony. I would say

(laughter)

S: But as Pamela, I think I agree from what I've read so far, it's so complicated basically, that at this point it is not possible to make any kind of reliable predictions.

PG: But the nice thing is that if it does cause a mini ice-age, well at least now we have the tools to measure it. So I'm all about the sun doing cool things that we can discover. There is lots of PhDs hidden in this research, it's just waiting to see what is happening is the annoying part.

S: SGU 5x5 is a companion podcast to the Skeptics' Guide to the Universe, a weekly science podcast brought to you by the New England Skeptical Society in association with skepchick.org. For more information on this and other episodes, visit our website at www.theskepticsguide.org. Music is provided by Jake Wilson.