From NASA News: Are Sunspots Disappearing?
September 3, 2009: The sun is in the pits of the deepest solar minimum in nearly a century. Weeks and sometimes whole months go by without even a single tiny sunspot. The quiet has dragged out for more than two years, prompting some observers to wonder, are sunspots disappearing?
“Personally, I’m betting that sunspots are coming back,” says researcher Matt Penn of the National Solar Observatory (NSO) in Tucson, Arizona. But, he allows, “there is some evidence that they won’t.”
Penn’s colleague Bill Livingston of the NSO has been measuring the magnetic fields of sunspots for the past 17 years, and he has found a remarkable trend. Sunspot magnetism is on the decline:
Above: Sunspot magnetic fields measured by Livingston and Penn from 1992 – Feb. 2009 using an infrared Zeeman splitting technique. [more]
“Sunspot magnetic fields are dropping by about 50 gauss per year,” says Penn. “If we extrapolate this trend into the future, sunspots could completely vanish around the year 2015.”
This disappearing act is possible because sunspots are made of magnetism. The “firmament” of a sunspot is not matter but rather a strong magnetic field that appears dark because it blocks the upflow of heat from the sun’s interior. If Earth lost its magnetic field, the solid planet would remain intact, but if a sunspot loses its magnetism, it ceases to exist.
“According to our measurements, sunspots seem to form only if the magnetic field is stronger than about 1500 gauss,” says Livingston. “If the current trend continues, we’ll hit that threshold in the near future, and solar magnetic fields would become too weak to form sunspots.””This work has caused a sensation in the field of solar physics,” comments NASA sunspot expert David Hathaway, who is not directly involved in the research. “It’s controversial stuff.”
The controversy is not about the data. “We know Livingston and Penn are excellent observers,” says Hathaway. “The trend that they have discovered appears to be real.” The part colleagues have trouble believing is the extrapolation. Hathaway notes that most of their data were taken after the maximum of Solar Cycle 23 (2000-2002) when sunspot activity naturally began to decline. “The drop in magnetic fields could be a normal aspect of the solar cycle and not a sign that sunspots are permanently vanishing.”
Penn himself wonders about these points. “Our technique is relatively new and the data stretches back in time only 17 years. We could be observing a temporary downturn that will reverse itself.”
The technique they’re using was pioneered by Livingston at the NASA-supported McMath-Pierce solar telescope near Tucson. He looks at a spectral line emitted by iron atoms in the sun’s atmosphere. Sunspot magnetic fields cause the line to split in two—an effect called “Zeeman splitting” after Dutch physicist Pieter Zeeman who discovered the phenomenon in the 19th century. The size of the split reveals the intensity of the magnetism.
Right: Zeeman splitting of spectral lines from a strongly-magnetized sunspot. [more]
Astronomers have been measuring sunspot magnetic fields in this general way for nearly a century, but Livingston added a twist. While most researchers measure the splitting of spectral lines in the visible part of the sun’s spectrum, Livingston decided to try an infra-red spectral line. Infrared lines are much more sensitive to the Zeeman effect and provide more accurate answers. Also, he dedicated himself to measuring a large number of sunspots—more than 900 between 1998 and 2005 alone. The combination of accuracy and numbers revealed the downturn.
If sunspots do go away, it wouldn’t be the first time. In the 17th century, the sun plunged into a 70-year period of spotlessness known as the Maunder Minimum that still baffles scientists. The sunspot drought began in 1645 and lasted until 1715; during that time, some of the best astronomers in history (e.g., Cassini) monitored the sun and failed to count more than a few dozen sunspots per year, compared to the usual thousands.
“Whether [the current downturn] is an omen of long-term sunspot decline, analogous to the Maunder Minimum, remains to be seen,” Livingston and Penn caution in a recent issue of EOS. “Other indications of solar activity suggest that sunspots must return in earnest within the next year.”
Whatever happens, notes Hathaway, “the sun is behaving in an interesting way and I believe we’re about to learn something new.”
h/t to Michael Ronayne
http://www.spaceweather.com/
“SOLAR MINIMUM VS. GLOBAL WARMING: From 2002 to 2008, decreasing solar irradiance has countered much anthropogenic warming of Earth’s surface. That’s the conclusion of researchers Judith Lean (NRL) and David Rind (NASA/GISS), who have just published a new analysis of global temperatures in the Geophysical Research Letters.”
rbateman (13:34:53) :
brings up a problem: If they are both correlated to the 11/22 year sun cycle, why would the spots then go down but not the Aurora?
I am just trying to figure out what Dr. Svalgaard is saying. My point is that the solar cycle (A) may both cause sun spots (B) and Aurora (C).
A may lead to B
A may lead to C
However, there is no direct connection between B and C. Sometimes the van der Pol oscillations inside the sun may lead to B, sometimes they may lead to C and sometimes they may lead to both B and C. Is this your opinion Dr. Svalgaard?
I have absolutely no reason to speculate, but based on my very limited understanding of the solar cycle I would guess that there is a link between the Aurora, the sunspots and, for example, the Arctic surface temperature:
http://climate4you.com/Polar%20temperatures.htm#NH%2070-90%20TempSince1900
We see that the previous temperature drop coincidences with the weak solar cycles 14 and 15. This is of course unscientific speculation only.
Mr. Alex (14:35:58) :
If one assumes that man caused the globe to warm significantly, and that assumption that the trace gas C02 trumps H20 as a heat trap is correct.
Which really leaves the Sun out of it, as less solar activity also corresponds with increased GCR’s which Svensmark’s experiment shows cause aerosols and H20 clouds to form increasingly. So, increased GCR’s should lead to increased efficiency of trapped heat to offset decreased solar irradience due to lower solar activity, and the reasoning goes into a tailspin.
Now you are down to a trace gas doing much the same thing, but not affected by solar activity and nothing to account for global temps falling.
With all the claims of ocean temps rising, polar caps melting, glaciers retreating and now Global Templs falling due to Deep Solar Minimum/decreased solar irradience offsets, it leads me to conclude that AGW at present is a scatterbrained hodgepodge of theory, hype, drum beating and tax schemes.
Time to lose the frantic dashing about to one alarm after another scenarios and knuckle down to a real story:
Deep Solar Minimum. That is what is happening right here, right now, on our doorsteps. Let’s deal with it, and get some focus.
When we have made our preparations for the coming cool-down, and we get our senses back, then we can revisit the AGW theory, and see what we have learned about how it stands with other forces, and should we need to do something about it, we’ll figure out what that is. It certainly should not be G&H Tax & Spill markets.
As far as I’m concerned, I’m still trying to get my head around “active Sun can’t cause warming”, “Inactive Sun causes cooling”.
DaveE.
DaveE (17:16:55) :
That’s because you need your CO2D2 decoder ring to decipher the encryption AlGorRhythm. It will lead you on a quest similar to National Treasure and DaVince Code. First stop is the Fortress of Solitude somewhere in Antarctica.
Invariant (15:43:20) :
I am just trying to figure out what Dr. Svalgaard is saying.
The aurora is a permanent feature and is present at all times. When the interplanetary magnetic field IMF and the solar wind are strong, the aurorae brighten and the auroral ‘oval’ [around the magnetic pole] expands. Under very disturbed conditions the oval may expand to low latitudes.
The IMF peaks at solar maximum, while the solar wind speed is often highest during the declining phase, so the aurorae [depending on both] tends to lag the solar cycle by a couple of years.
Interesting article on spaceweather.com.
“The warmest year on record, 1998, coincides with the ‘super-El Nino’ of 1997-98,” points out Lean. “The ESNO is capable of producing significant spikes in the temperature record.” Solar minimum has the opposite effect: “A 0.1% decrease in the sun’s irradiance has counteracted some of the warming action of greenhouse gases from 2002 – 2008,” she notes. “This is the reason for the well-known ‘flat’ temperature trend of recent years.”
“This is the reason for the well-known ‘flat’ temperature trend of recent years.”
Well, at least she’s willing to own up to that.
Ric Werme (09:17:49) :
I don’t think you understand, did you read the papers?
This is brand new science. Livingston and Penn are the first to report this phenomemon and are quick to say they don’t know how things will turn out.
I did, however I will admit probably with not quite so much focus as needed the first time.
The trend appears to be a straight line, so that what they fit it to. What would you have used?
The analysis of direct data is over 17 years, on a system that has been oscillating for many orders of magnitude more than that – I would be very reticent about [a] trying to fit a straight line to any natural system and [b] attempting any kind of trend analysis on such a small set of data.
Really, that was the major nub of my earlier ‘rant’.
Please, go bang your head
Already done :o)
– several of rest of us who have been following this find this to be the most fascinating thing we have read in this blog, some to the point of checking with Leif after each sunspeck with “Did Livingston measure it?” “Is it still on the trend line?”
Each to their own and whatever floats-your-boar is fine by me. Personally, I think monitoring each and every development is a futile exercise as we have no idea how long any cycle might be (better to accumulate then look back). However, that’s just my view and I fully understand when something new tickles the fancy it can be fascinating to follow.
I’m more patient than that, perhaps if you read both of the papers you would understand that you could learn a little patience yourself
I will freely admit I was in somewhat of a rush in my previous posting, mea-culpa; patience is something I normally have in abundance (with three kids 17, 13 and 5, you have to have it).
I agree that the papers and more cautious and balanced than a scan reading inferred and my vective may have been better aimed elsewhere. However, I stand by my point regarding trying to fit ‘trend’ lines to potentially small data sets. I guess I am becoming skeptical of smoothing and trend analysis in general – I wonder why…
Cheers
Mark
Doh – floats your boar??
Bugger it, Sunday morning and half asleep, try “boat” instead :o)
<i<DaveE (12:58:04) : Does anyone actually use the current temp reading? If so, what for?
Well, I see it on the nightly weather reports…
rbateman (16:53:58) :
“it leads me to conclude that AGW at present is a scatterbrained hodgepodge of theory, hype, drum beating and tax schemes.”
I agree with you, I just linked that article because it was the first of its kind on spaceweather in a while.
I can’t say I agree with most of the article’s points because there surely is some sort of lag, ie this solar minimum won’t come through in the climate for a few years, (it cannot be instantaneous).
“James F. Evans (23:38:47) :
“This is the reason for the well-known ‘flat’ temperature trend of recent years.”
Well, at least she’s willing to own up to that.”
The climate computer models which assumed CO2 to be the main driver did not predict this as it was not allowed , therefore the initial IPCC hypothesis is invalidated.
I hope Nasif Nahle’s posts following Anthony’s intervention indicate that he contacted both Leif and Anthony off-blog and sorted out the issue (whatever it was).
I enjoy Nasif’f posts and hope he can contain his fiery Latin temperament so we can continue to have the benefit of his information and insight.
Mr. Alex (02:11:43) :
The part of the Solar Activity that is part of the daily surface heating should be instantaneous. It’s just moderated by the residual, much as a summer day following a cooling trend doesn’t make it as high in temp as a previous hot day.
It would be one heck of a rude awakening if, one day, we learned that the present 0.1drop in TSI isn’t all that there is.
Mark Fawcett (00:08:10) :
That’s certainly a fair criticism, and I think everyone involved would love to have a longer data set. There’s a tacit assumption (expectation!) that whatever is going on has happened many times before with likely little harm. If it’s what’s behind the Dalton and Maunder Minima, and it will be impossible to prove, then great. Of course, it would mean at best trading one question for another (what caused the magnetic field strength to decline?)
The straight line approximation cannot hold for the indefinite future, of course. If it is part of 100 year cycle, then the slope will have to go back up sometime. The definitive paper will have to wait for two or three full cycles or for a convincing theoretical solution, but that’s longer than I care to wait!
Please excuse me for not carefully reading the entire article.
“According to our measurements, sunspots seem to form only if the magnetic field is stronger than about 1500 gauss,” says Livingston. “If the current trend continues, we’ll hit that threshold in the near future, and solar magnetic fields would become too weak to form sunspots.”
My previous post…
“The article says “Sunspot magnetic fields are dropping by about 50 gauss per year,” says Penn. “If we extrapolate this trend into the future, sunspots could completely vanish around the year 2015.”
According to the graph, by 2015, mag fields will be only 1800 gauss. Is that the point at which sunspots vanish? I think someone drew a conclusion from the chart without realizing that the y axis ranged from 1800 to 3200 gauss.”