From UCAR: Extended solar minimum linked to changes in Sun’s conveyor belt
BOULDER—A new analysis of the unusually long solar cycle that ended in 2008 suggests that one reason for the long cycle could be a stretching of the Sun’s conveyor belt, a current of plasma that circulates between the Sun’s equator and its poles. The results should help scientists better understand the factors controlling the timing of solar cycles and could lead to better predictions.
The study was conducted by Mausumi Dikpati, Peter Gilman, and Giuliana de Toma, all scientists in the High Altitude Observatory at the National Center for Atmospheric Research (NCAR), and by Roger Ulrich at the University of California, Los Angeles. It appeared on July 30 in Geophysical Research Letters. The study was funded by the National Science Foundation, NCAR’s sponsor, and by NASA’s Living with a Star Program.
The Sun goes through cycles lasting approximately 11 years that include phases with increased magnetic activity, more sunspots, and more solar flares, than phases with less activity. The level of activity on the Sun can affect navigation and communications systems on Earth. Puzzlingly, solar cycle 23, the one that ended in 2008, lasted longer than previous cycles, with a prolonged phase of low activity that scientists had difficulty explaining.
The new NCAR analysis suggests that one reason for the long cycle could be changes in the Sun’s conveyor belt. Just as Earth’s global ocean circulation transports water and heat around the planet, the Sun has a conveyor belt in which plasma flows along the surface toward the poles, sinks, and returns toward the equator, transporting magnetic flux along the way.
“The key for explaining the long duration of cycle 23 with our dynamo model is the observation of an unusually long conveyor belt during this cycle,” Dikpati says. “Conveyor belt theory indicates that shorter belts, such as observed in cycle 22, should be more common in the Sun.”
Recent measurements gathered and analyzed by Ulrich and colleagues show that in solar cycle 23, the poleward flow extended all the way to the poles, while in previous solar cycles the flow turned back toward the equator at about 60 degrees latitude. Furthermore, as a result of mass conservation, the return flow was slower in cycle 23 than in previous cycles.
In their paper, Dikpati, Gilman, and de Toma used simulations to model how the solar plasma conveyor belt affected the solar cycle. The authors found that the longer conveyor belt and slower return flow could have caused the longer duration of cycle 23.
The NCAR team’s computer model, known as the Predictive Flux-transport Dynamo Model, simulates the evolution of magnetic fields in the outer third of the Sun’s interior (the solar convection zone). It provides a physical basis for projecting the nature of upcoming solar cycles from the properties of previous cycles, as opposed to statistical models that emphasize correlations between cycles. In 2004, the model successfully predicted that cycle 23 would last longer than usual.
According to Dikpati, the duration of a solar cycle is probably determined by the strength of the Sun’s meridional flow. The combination of this flow and the lifting and twisting of magnetic fields near the bottom of the convection zone generates the observed symmetry of the Sun’s global field with respect to the solar equator.
“This study highlights the importance of monitoring and improving measurement of the Sun’s meridional circulation,” Ulrich says. “In order to improve predictions of the solar cycle, we need a strong effort to understand large-scale patterns of solar plasma motion.”
About the article
Title: Impact of changes in the Sun’s conveyor-belt on recent solar cycles
Authors: Mausumi Dikpati, Peter Gilman, Giuliana de Toma, and Roger Ulrich
Publication: Geophysical Research Letters
Mac the Knife says:
August 17, 2010 at 8:02 am
Dikpati says. “Conveyor belt theory indicates that shorter belts,
The discussion may be moot as there does not seem to even be a conveyor belt, but several cells on top of one another going inward.
http://www.holoscience.com/news.php?article=ah63dzac
http://www.thunderbolts.info/tpod/2010/arch10/100812sun.htm
http://www.thunderbolts.info/tpod/2010/arch10/100812sun.htm
fred houpt says:
August 17, 2010 at 8:19 am
http://www.holoscience.com/news.php?article=ah63dzac
Which claims that “sunshine is a spherical electric discharge phenomenon powered by the galaxy”. Far out…
ShrNfr:
I vote to send Mann to the location
————
Mann would not want to expose himself to danger so would prefer to go at night
Leif Svalgaard says:
August 17, 2010 at 6:59 am (Edit)
The latest helioseismology data [presented at SHINE 2010] indicate that there does not seem to be a conveyor belt at all, but rather several cells, both in latitude and more importantly at depth. What we observe at the surface does not seem to reflect very well what goes on deep within the Sun. SDO will in the coming years tell us more about the circulation(s).
Looks like all bets are off for now then with dynamologer’s theories.
David Hathaway was refreshingly frank about it in a recent interview.
FLATOW: So are there really set cycles the sun goes through? Why does it go through these cycles? Why isn’t it just stable?
Dr. HATHAWAY: Oh, yeah, great question. I wish I knew the answer. It goes through a cycle of about 11 years with sunspots, but again, about 11 years, it varies by, give or take, about one year. And the thing that really surprised us this time is that the last cycle, it took 12 years and three months before the next cycle really got started. And that’s -the late start is indicative of a small cycle, but it’s all related to magnetism, magnetic fields generated within the sun. That much we know for sure. The precise details on how it does that or – is, again, where the devil is. But we’re learning more about it.
We’re sure of some aspects as far as how flows within the sun take the magnetic fields and drag them around and stretch them out and twist them up. But for the last decade, I thought we had it figured out, until this sunspot cycle minimum came around and there were a number of unexpected things that makes me believe that at least my understanding of how it worked, that I thought was correct for the last 10 years, is in error. So we were – it’s…
FLATOW: So we thought we knew how the sun works, but we’re not quite sure.
Dr. HATHAWAY: Yeah, certainly I’m not.
tallbloke says:
August 17, 2010 at 8:48 am
Looks like all bets are off for now then with dynamologer’s theories.
Dr. HATHAWAY: Yeah, certainly I’m not.
1) Hathaway is not a dynamo modeler.
2) his geomagnetic peak theory didn’t work because he picked the wrong peak
There is a class of dynamo models that are right on track for SC24.
I suppose we should be grateful for the computer simulation failing to make predictions and now giving answers after the fact.
How much could that have cost us, 5-10 million dollars?
Whereas The ILC (International Linear Collider) is in the planning stage and the DOE is estimating it may cost 20 billion dollars.
I say give them computer models instead, let them make press releases, and ignore them.
And to further harp on my sad theme of crying over spilt milk,
the continuous nuclear reaction which is supposed to be powering the sun, and all other stars, based on a theory started in 1923, has never been accomplished in a reactor.
The figure spent on that theory is also in the billions and billions of tax dollars.
Zeke the Sneak says:
August 17, 2010 at 9:14 am
the continuous nuclear reaction which is supposed to be powering the sun, and all other stars, based on a theory started in 1923, has never been accomplished in a reactor.
Of course it has [way back in 1932], but not in a sustained or controlled fashion [Hydrogen bombs]. The theory that put men on the Moon is from 1666.
Paul Birch says:
The “dark matter” craze is mostly a media misunderstanding of some standard astrophysics.
I agree.
There is nothing mystic about dark mater. It’s a matter of our observational limitations. We don’t know how many galaxies have collapsed into singularities and have become non luminous super massive objects.
Our visible universe appears much like a sponge held together by filaments of active mater. The voids are said to have a lower density than the surrounding filaments of active mater. This may be true on average but it doesn’t mean that a supper massive object doesn’t reside within. It’s possible that the void exists because the mater has been consumed by the NLSMO.
ShrNfr:
I vote to send Mann to the location
Seconded…. maybe he can find some interesting coronal proxies 😉
Leif Svalgaard says:
August 17, 2010 at 9:35 am
Zeke the Sneak says:
August 17, 2010 at 9:14 am
the continuous nuclear reaction which is supposed to be powering the sun, and all other stars, based on a theory started in 1923, has never been accomplished in a reactor.
Of course it has [way back in 1932], but not in a sustained or controlled fashion [Hydrogen bombs].
That is what I said. The point is how much it is costing us.
And historical note for comparison: A tiny fraction of that amount of time and money was spent on cold fusion, before it was declared to be impossible.
Zeke the Sneak says:
August 17, 2010 at 10:00 am
–the continuous nuclear reaction which is supposed to be powering the sun–
That is what I said. The point is how much it is costing us.
The ‘offensive’ word was ‘supposed’.
About the cost: it is tiny compared to what society is willing to spent on other things, e.g. Wars, Bailouts, etc.
@Paul Birch:
Thanks for the clarification, however I’m still very sceptical:
“But, based on the observed luminosity, the total mass of visible stars (the “light matter”) is too low to account for the velocity curves. So there must be more mass we don’t see (the “dark matter” or “missing mass”).”
There must?
“This comprises the interstellar medium of neutral gas, dust, dark nebulae, planetary bodies, brown dwarfs (stars and sub-stars too faint to see), ordinary stars hidden by dust, neutron stars, black holes, and other junk.”
I’d find the theory more palatable if this was all it was talking about with regard to the “missing matter”, though you’ve included at least one more theoretical construct in that list (black holes).
“There’s nothing particularly mysterious about it – we know it’s there”
We do? How?
” – and we don’t have to rely on any weird quantum particles or strange fields (though they cannot be entirely ruled out).”
What is being proposed is very strange – even given the list you provide above it is a colossal ask to entertain the idea that this is what makes up 80% of the matter supposed to exist in the universe; the calculation for which is IIRC based on the Big Bang Theory, which is even more of a mind-bending LSD tripping whacky theory, and a First Cause argument to boot.
What is being described appears to be artefacts of the underlying theory, not something based primarily on observation.
Unless I’ve misunderstood you, you appear to be saying that the ‘popular’ concept of Dark Matter is completely wrong – so, to use Wikipedia as an example: “The largest part of dark matter, which does not interact with electromagnetic radiation, is not only “dark” but also, by definition, utterly transparent.” – is this completely wrong?
(http://en.wikipedia.org/wiki/Dark_matter)
Here’s what someone at NASA says about it: “The search for the nature of dark matter is a very active field in astronomy and physics. Scientists do not know what it is made of, but they are investigating a number of possibilities.”
http://imagine.gsfc.nasa.gov/docs/teachers/galaxies/imagine/dark_matter.html
We “know” it’s there, but don’t know what it is, or how to detect it, except by extreme inference.
I’m sorry, I’m having great difficulty accepting this as in any way solid (slight pun intended). 😛
At this point, I do not think it is clear, even with a history of over 300 years of solar observations, if we are observing the random processes of solar surface weather or a potentially predictable solar climate. This particular paper seems to suggest that the duration of solar cycle 23 may have been extended due to a collapse of a proposed northern polar minor circulation cell. Perhaps this was an irregular random event. The article, as presented, seems to lack any discussion of the state of what should be an equivalent southern polar circulation cell. It might be interesting to consider the possible consequences and probabilities of losing both cells at the same time.
One might want to be on the lookout for something special happening on the sun whenever the presumed defunct northern circulation cell is resumes operation.
It is appropriate to say that nuclear reactions are “supposed” to power the sun, as all science is provisional and we have limited data and need more instruments and more measurements. I have not offended.
And the billions spent on this sustained nuclear reaction is not at all tiny. It is only tiny to the government who took it from the taxpayer.
MartinGAtkins says:
August 17, 2010 at 9:41 am
“[…]
There is nothing mystic about dark mater. It’s a matter of our observational limitations. We don’t know how many galaxies have collapsed into singularities and have become non luminous super massive objects.
Our visible universe appears much like a sponge held together by filaments of active mater. The voids are said to have a lower density than the surrounding filaments of active mater. This may be true on average but it doesn’t mean that a supper massive object doesn’t reside within. It’s possible that the void exists because the mater has been consumed by the NLSMO.”
I disagree. From what i know, Zwicky used the Virial theorem to estimate the amount of matter necessary to explain the motion of a spiral galaxy, where inner and outer parts rotate around the center with the same periodicity – so the entire spiral galacy keeps its structure. He concluded that there has to be a large amount of unobserved or dark matter to explain this motion. AFAIK that was how the concept of dark matter got invented. It was necessary to fix a chasm between theory and observation.
Also, your supermassive objects would have to be detectable by their gravity lens effect.
Zeke the Sneak says:
August 17, 2010 at 10:12 am
It is appropriate to say that nuclear reactions are “supposed” to power the sun, as all science is provisional
It was ‘supposed’ to many decades ago, but no longer. In all science there comes a point where we stop saying ‘supposed’ and that point is way past for what powers the sun. We also do not say any longer: ‘the Earth is supposed to be round and not flat’.
These are the same people that predicted the gulf oil spill would be off the coast of New England. I don’t trust their models, no matter what they are.
http://www2.ucar.edu/news/oil-spill-animations-multimedia-gallery
Leif Svalgaard says:
August 12, 2010 at 7:34 pm
I’m in principle suspicious of claims that are ‘beyond doubt’.
Zeke the Sneak says:
August 17, 2010 at 10:29 am
“I’m in principle suspicious of claims that are ‘beyond doubt”.
You are confusing ‘claims’ and established fact. In science, once evidence becomes overwhelming, it is no longer a ‘claim’, but a ‘fact’. Round Earth, Heliocentric solar system, Expansion of space, Evolution, etc. Now, for each of these you can always find hold-outs who dispute them, but that does not change anything.
Computer models are useful to help flesh out a concept od illustrate something. They are no substitute for observation and experimentation; they are neither data nor experiments.
Leif Svalgaard says:
August 17, 2010 at 10:41 am
You are confusing ‘claims’ and established fact. In science, once evidence becomes overwhelming, it is no longer a ‘claim’, but a ‘fact’.
To be very specific, the ‘claims’ regarding the thermonuclear sun with a dynamo generating the complex magnetic fields, and conveyor belts,
graduated to scientific ‘fact’ in the ’20’s. No other hypothesis has been deeply considered, ever.
Now a claim that becomes a fact without any possible chance of falsification is still a claim. A very expensive multi-billion dollar claim that cannot make predictions and is lacking in basic explanatory power. See tallbloke’s post.
Didn’t their backcast “prove” their earlier model 98% accurate (at least until reality set in)? Anyway, it seems like it boils down to they just need more money so they can predict randomness.