Modeling sunspots during times when few are seen

(h/t to Michael Ronayne)

NCAR

Sunspots Revealed in Striking Detail by Supercomputers

BOULDER—In a breakthrough that will help scientists unlock mysteries of the Sun and its impacts on Earth, an international team of scientists led by the National Center for Atmospheric Research (NCAR) has created the first-ever comprehensive computer model of sunspots. The resulting visuals capture both scientific detail and remarkable beauty.

flower-like shape; dark center, bright petals

The interface between a sunspot's umbra (dark center) and penumbra (lighter outer region) shows a complex structure with narrow, almost horizontal (lighter to white) filaments embedded in a background having a more vertical (darker to black) magnetic field. Farther out, extended patches of horizontal field dominate. For the first time, NCAR scientists and colleagues have modeled this complex structure in a comprehensive 3D computer simulation, giving scientists their first glimpse below the visible surface to understand the underlying physical processes.

The high-resolution simulations of sunspot pairs open the way for researchers to learn more about the vast mysterious dark patches on the Sun’s surface. Sunspots are the most striking manifestations of solar magnetism on the solar surface, and they are associated with massive ejections of charged plasma that can cause geomagnetic storms and disrupt communications and navigational systems. They also contribute to variations in overall solar output, which can affect weather on Earth and exert a subtle influence on climate patterns.

The research, by scientists at NCAR and the Max Planck Institute for Solar System Research (MPS) in Germany, is being published this week in Science Express.

“This is the first time we have a model of an entire sunspot,” says lead author Matthias Rempel, a scientist at NCAR’s High Altitude Observatory. “If you want to understand all the drivers of Earth’s atmospheric system, you have to understand how sunspots emerge and evolve. Our simulations will advance research into the inner workings of the Sun as well as connections between solar output and Earth’s atmosphere.”

Ever since outward flows from the center of sunspots were discovered 100 years ago, scientists have worked toward explaining the complex structure of sunspots, whose number peaks and wanes during the 11-year solar cycle. Sunspots encompass intense magnetic activity that is associated with solar flares and massive ejections of plasma that can buffet Earth’s atmosphere. The resulting damage to power grids, satellites, and other sensitive technological systems takes an economic toll on a rising number of industries.

Creating such detailed simulations would not have been possible even as recently as a few years ago, before the latest generation of supercomputers and a growing array of instruments to observe the Sun. Partly because of such new technology, scientists have made advances in solving the equations that describe the physics of solar processes.

The work was supported by the National Science Foundation, NCAR’s sponsor. The research team improved a computer model, developed at MPS, that built upon numerical codes for magnetized fluids that had been created at the University of Chicago.

Computer model provides a unified physical explanation

The new computer models capture pairs of sunspots with opposite polarity. In striking detail, they reveal the dark central region, or umbra, with brighter umbral dots, as well as webs of elongated narrow filaments with flows of mass streaming away from the spots in the outer penumbral regions. They also capture the convective flow and movement of energy that underlie the sunspots, and that are not directly detectable by instruments.

The models suggest that the magnetic fields within sunspots need to be inclined in certain directions in order to create such complex structures. The authors conclude that there is a unified physical explanation for the structure of sunspots in umbra and penumbra that is the consequence of convection in a magnetic field with varying properties.

The simulations can help scientists decipher the mysterious, subsurface forces in the Sun that cause sunspots. Such work may lead to an improved understanding of variations in solar output and their impacts on Earth.

Supercomputing at 76 trillion calculations per second

To create the model, the research team designed a virtual, three-dimensional domain that simulates an area on the Sun measuring about 31,000 miles by 62,000 miles and about 3,700 miles in depth – an expanse as long as eight times Earth’s diameter and as deep as Earth’s radius. The scientists then used a series of equations involving fundamental physical laws of energy transfer, fluid dynamics, magnetic induction and feedback, and other phenomena to simulate sunspot dynamics at 1.8 billion points within the virtual expanse, each spaced about 10 to 20 miles apart. For weeks, they solved the equations on NCAR’s new bluefire supercomputer, an IBM machine that can perform 76 trillion calculations per second.

The work drew on increasingly detailed observations from a network of ground- and space-based instruments to verify that the model captured sunspots realistically.

The new models are far more detailed and realistic than previous simulations that failed to capture the complexities of the outer penumbral region. The researchers noted, however, that even their new model does not accurately capture the lengths of the filaments in parts of the penumbra. They can refine the model by placing the grid points even closer together, but that would require more computing power than is currently available.

“Advances in supercomputing power are enabling us to close in on some of the most fundamental processes of the Sun,” says Michael Knölker, director of NCAR’s High Altitude Observatory and a co-author of the paper. “With this breakthrough simulation, an overall comprehensive physical picture is emerging for everything that observers have associated with the appearance, formation, dynamics, and the decay of sunspots on the Sun’s surface.”

aerial

First view of what goes on below the surface of sunspots. Lighter/brighter colors indicate stronger magnetic field strength in this subsurface cross section of two sunspots. For the first time, NCAR scientists and colleagues have modeled this complex structure in a comprehensive 3D computer simulation, giving scientists their first glimpse below the visible surface to understand the underlying physical processes. This image has been cropped horizontally for display. [ENLARGE & DISPLAY FULL IMAGE] (©UCAR, image courtesy Matthias Rempel, NCAR. News media terms of use*)

See a video animation of this and other sunspot visualizations as well as still “photo” images in the Sunspots Multimedia Gallery.

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“With this breakthrough simulation, an overall comprehensive physical picture is emerging for everything that observers have associated with the appearance, formation, dynamics, and the decay of sunspots on the Sun’s surface.”
A bit of hype here “everything”. As with all models the result depends on what you put in. Models do not create new knowledge, but helps visualize existing knowledge, in combination with assumptions about what you don’t know yet. If the model does not quite explain “everything” you can try varying your assumptions to see what might have to be changed in a way consistent with the equations that you have posited from the outset. A persistent problem in solar magnetic modeling is that as you go to finer and finer scales, the less accurate the model becomes because of lack of computer power, while at the same time telling us that the most interesting things [and determining factors] happen at still finer scales.

anna v

To create the model, the research team designed a virtual, three-dimensional domain that simulates an area on the Sun measuring about 31,000 miles by 62,000 miles and about 3,700 miles in depth – an expanse as long as eight times Earth’s diameter and as deep as Earth’s radius. The scientists then used a series of equations involving fundamental physical laws of energy transfer, fluid dynamics, magnetic induction and feedback, and other phenomena to simulate sunspot dynamics at 1.8 billion points within the virtual expanse, each spaced about 10 to 20 miles apart. For weeks, they solved the equations on NCAR’s new bluefire supercomputer, an IBM machine that can perform 76 trillion calculations per second.
Oh dear.

D. King

involving fundamental physical laws of energy transfer, fluid dynamics, magnetic induction
Sounds good.
and feedback, and other phenomena to simulate sunspot dynamics at 1.8 billion points within the virtual expanse,
Uh oh.

rbateman

while at the same time telling us that the most interesting things [and determining factors] happen at still finer scales.
That’s an eye-opener, Leif.

Maybe next they can simulate the Cubs winning the pennant.
Isn’t virtual reality wonderful? If I had a supercomputer there’s no telling what I would simulate. My first choice would be a rational world, but that’s pretty farfetched. Maybe I’d just start off with a rational neighborhood.
Thank goodness somebody is engaged in reality-based activities, such as farming, forestry, and that boring food-clothing-shelter stuff. Otherwise the Great Philosophers of Science would go hungry, naked, and wandering aimlessly in the snow.

timetochooseagain

Computers are the new experiments. God help the scientific method….

AnonyMoose

I’ll call this a good start.

crosspatch

Sounds like someone desperate to justify funding. Something looks oddly too symmetrical about it to me.

KimW

So the model just shows what we already know or infer and cannot show anything we do not. Too bad if there is anything new and unknown.
Some people might confuse this withan actual “Experiment” with real observations.

Kath

It doesn’t clearly explain some of the structures I’ve seen in photographs of a sunspot, but it’s a start. In my branch of the sciences, computer models have to be supported by experiments and verified.

JFA in Montreal

Garbage In – Garbage Out …

anna v

timetochooseagain (11:31:14) :
Computers are the new experiments. God help the scientific method….
When I was a graduate student back in the 1960’s I remember having strong arguments with a freshly arrived from England computer PhD , who was adamant in maintaining that pretty soon there would be no need for experiments like the CERN experiments because computers could simulate all experiments.
Not much has changed since then in people mesmerized by computing, except the power of computers, since my laptop is now more powerful than the “supercomputer” of the time.

Douglas DC

Why am I thinking of “Hitchiker’s Guide to the Galaxy”-“Deep Thought” supercomputer?

MikeN

Well the model is predicting a comeback for the sun soon.

pwl

Pass the grains of salt please for we need a dose… models are excellent, as another above said, for learning and putting our knowledge or lack there of to the test to see how accurate it is with Nature. If you fail to test the model against the actual objective reality then you’re not doing science but you’re in the special effects business for the next Star Trek Film – Journey to the Center of the Sun.
Remember all the limitations, inaccuracies, misrepresentations, foibles, and possibly even all the conclusions of models that apply to climates on Earth also applies to models of the super tropical climate on Sol.
Of course if a model of the Sun’s spots was accurate the computer running the model and everything else on Earth would be instantly incinerated. Since to model the sun accurately you’d need to recreate it! Let’s not and say we did. 😉

Dave Wendt

Leif Svalgaard (10:45:28)
A persistent problem in solar magnetic modeling is that as you go to finer and finer scales, the less accurate the model becomes because of lack of computer power, while at the same time telling us that the most interesting things [and determining factors] happen at still finer scales.
If computing power is really the main drawback of these models, they may indeed be more helpful in the not to distant future. Although the bluefire machine they used was delivered only a little over a year ago, it is already well off the state of the art. The best machines are now well into the PetaFlop range, i.e. doing 1-4 million billion calcs/sec and I’ve seen a recent report of a new machine in the pipeline which will be pushing the 100 PFlop barrier in a few years. The only things that seem to be limiting the development of supercomputer tech right now are the massive amounts of money and the massive supplies of energy they require.

Mike McMillan

Supercomputing at 76 trillion calculations per second
I could use a faster computer, but it’d still be on dial-up.

Gordon Ford

Ground truthing that model will be interesting!

Robert Wood

Constructing a computer model is a valuable exercise for understanding what we know, but it doesn’t create data, nor prove theories. It is merely a tool for exploring the complex interactions of mathemateical equations – which are the real models.

Bill Illis

There is still a way to go with this simulation I imagine.
The Swedish 1 Metre Solar Telescope seems to produce the best close-up pictures of the Sun using adaptive optics.
There is a lot of 3D effects that don’t seem to be properly caught in the simulation if you can see the different 3D structures in a sunspot in this image which is probably the best close-up ever taken of the interior of a sunspot.
http://www.solarphysics.kva.se/gallery/images/2003/halpha_22Aug2003_AR.4996.MFBD_color.jpg
other pics.
http://www.solarphysics.kva.se/gallery/images/2003/gband_02Jun2003_AR373.2539.MFBD_color.jpg
http://www.solarphysics.kva.se/gallery/images/2002/24jul02_gcont_ai.jpg
This movie takes awhile to fully load but is quite amazing.
http://www.solarphysics.kva.se/gallery/movies/oslo-2004/movies/gband_20Aug2004_sunspot_41min_color.mpg
Home page with other pics and movies.
http://www.solarphysics.kva.se/

Dave Wendt (12:36:31) :
I’ve seen a recent report of a new machine in the pipeline which will be pushing the 100 PFlop barrier in a few years.
The ‘modern’ supercomputers achieve their massive throughput by running thousands of threads or even CPUs in parallel. This works for problems that can be ‘parallelized’ , but does not help much for ‘serial’ problems, so there are problems that cannot benefit from that kind of supercomputer, namely those where the next step depends on the previous step.

Ray

I can’t look at that picture… My vision throbs!

Katherine

For the first time, NCAR scientists and colleagues have modeled this complex structure in a comprehensive 3D computer simulation, giving scientists their first glimpse below the visible surface to understand the underlying physical processes.

Shouldn’t that be “what they think lies below the visible surface”? It’s just a model after all, not the real thing.

KlausB

re: {B} Leif Svalgaard (14:02:18) :
The ‘modern’ supercomputers achieve their massive throughput by running thousands of threads or even CPUs in parallel. This works for problems that can be ‘parallelized’ , but does not help much for ’serial’ problems, so there are problems that cannot benefit from that kind of supercomputer, namely those where the next step depends on the previous step.{/b}
Leif, yep, that’s it.
It was already tried to distibute preliminary results on massive parallel computers,
to bypass the step by step chain. A hell to program it, not worth the effort.
Was there, saw that. And it did’t make sense to me.

Aelric

On a lighter note:
Let us hope that the authors didn’t submit the ‘Eye of Sauron’ jpg by mistake!

kim

Heh, we know the GCMs poorly model convection. Convection leads to turbulence, which becomes difficult to model. How do we know this sunspot program adequately models convection?
==========================================

kim

Leif, could one of those ‘more interesting things happening at finer scales’ be the tidal movements of mere millimeters?
===============================================

Dave Wendt

Bill Illis (13:41:59) :
Thanks for the links to those images, they are incredibly beautiful and fascinating!

Dave Wendt

The ‘modern’ supercomputers achieve their massive throughput by running thousands of threads or even CPUs in parallel. This works for problems that can be ‘parallelized’ , but does not help much for ’serial’ problems, so there are problems that cannot benefit from that kind of supercomputer, namely those where the next step depends on the previous step.
Good point. I guess when it comes to computers, speed and power are not necessarily synonymous. Do the GCMs have this sort of unsuitability to parallelization also and might not attempting to tweak a model to run on a massively parallel computer system lead to distortions in the output?

Leon Brozyna

Not another computer model. There’s almost a mystical aura surrounding this tool. And that’s all that it is – a tool, a guide. And it has limitations. As Dr. Svalgaard said, “[it] helps visualize existing knowledge.” And it’ll also help show you what you think you know is wrong when the model eventually fails to emulate reality.

tallbloke

A persistent problem in solar magnetic modeling is that as you go to finer and finer scales, the less accurate the model becomes because of lack of computer power, while at the same time telling us that the most interesting things [and determining factors] happen at still finer scales.
Big fleas have little fleas
Upon their backs to bite em
And the little fleas have smaller fleas
and so ad infinitum

GlennB

Looks like we have another spot middle south. Not picked up on yet, maybe cause it’s Sunday.
http://sohowww.nascom.nasa.gov/data/realtime/mdi_igr/512/
An interesting find circa 1898:
“It must have been visible as a notch on the limb on the preceding afternoon, but had not come into view in the morning, when the usual photographs were taken.”
http://articles.adsabs.harvard.edu//full/1898Obs….21..375M/0000375.000.html
Does this suggest that if a spot was not visible when photographs were taken in the morning, that any spots showing up later during the day and dissapearing before the next morning would not have been recorded?

David Holliday

As much as I have denigrated the use of Global Climate Models (GCM), my read of this research is that the application of computer modeling is entirely appropriate. The difference is in how the models are being used. GCM’s are being used to project forward in order to predict climate on the basis of unproven theories and an incomplete understanding of climate drivers. In this research the model is being used to reconstruct phenomena using well understood principles and detailed observed data. In the GCM case you have a model being used to give false confidence in an outcome the likelihood of which is far from certain. In this case you have a model being used to increase confidence in the understanding of the underlying forces causing the phenomena. This case is an example of how computer models should be used. The GCM case is an example of how computer models can be used to give the appearance of confidence when there is none.

J.Hansford

Hmmm… Computer models again?
As long as they understand they are only attempting to model what they already know.
Nothing new will arise from it. It is simply an idea for a hypothesis on something new, that observation and experimentation will still have to prove…..
Once upon a time, people used to just use their imagination rather than a computer generated image to visualize a concept. Those that could conceptualize their accumulated knowledge and apply that in a good guess for uncovering the secrets yet unknown…. Became great men and women of science.
….. So the pitfall here is, instead of seeking out the secrets of the natural universe…. They’ll get sidetracked tweaking their Computer program so that their representation of a Hypothesis fits with accepted orthodoxy and looks, “real-er”.
… Sorta sounds familiar somehow?

Bobby Lane

As Leif said, GIGO. Yet another computer model purporting to explain an enormously complex natural system about which we have not a lot of substantial research into its complex behaviors. All they will use this to do is to either: 1) explain why sunspots do affect climate and thus control the dialogue by controlling the “results,” or 2) coming to a consensus that sunspots don’t have that much of an effect when the sun ramps back up and stops being a part of the 24 hour news cycle to any significant degree.

Michael Ronayne

Being a very big fan of fractals I was at first awe struck by the beauty of the images which are undeniable. Then I realized that there is a very significant flaw in the graphics. There is no color scale calibration legend which should have been included with all of these graphics. We are all assuming that we know what the colors mean and the intensity scales which are being used. This was no small omission and I have written about this practice in the past when such graphics are used for deception which is not the case here. In this case, I suspect that the researches were as captivated by the beauty as I was and still am. In the face of such beauty you need a really paranoid personality, such as mine, to note the omission. Hopefully the next iteration of the graphics will contain a legend.
Mike

Retired Engineer

Mike D. (11:29:21) :
“Maybe next they can simulate the Cubs winning the pennant.”
They would need a bigger computer …
“Otherwise the Great Philosophers of Science would go … wondering aimlessly in the snow.”
They don’t now ?
I suspect things happen on a finer scale then 18 miles per data point. Same problem with GCM’s. Coarse resolution, and insufficient data to start with. So they make assumptions. Which are the mother of all foul ups.
But, they have to spend our tax dollars somehow.

Gary Strand

The commentators who dismiss computer modeling – I wonder if any are engineers, who live by computer models these days. Consider that the next new bridge you may cross or skyscraper you go into was modeled on a computer. Do you still believe models are worthless?
Likewise, how would one run an experiment on the sun? Or, something much easier – how would you run an experiment on the climate system?

Jack Green

I’m one of those engineers that lives by computer models and I hate to attack my own profession but it’s a function of the data input. If you don’t have good data then you don’t get good output. Garbage in = Garbage out. Still it’s the process that leads to understanding over the long term that matters and you never get the answer you get a range. Our job is to tell the truth and not project things that aren’t there.

Kath

Found this web page “Academic phrases translated”
http://www.thesabloggers.org/2009/06/just-for-grins-academic-phrases-translated.html
Samples:
Academic phrase with (translation):
“A statistically-oriented projection of these findings…” (A scientific wild guess.)
“Additional study will be required for a more complete understanding of this phenomenon…” (I didn’t understand this, and probably never will.)
“A definite trend is evident..”‘ (This data is practically meaningless.)
“Correct within an Order of Magnitude…” (Wrong. Wrong. Wrong.)
“It is generally believed…” (A couple of others think so, too.)
…..

actuator

Computer models are just fine when you are dealing with problems where the variables are all known with precision. With many engineering models the knowledge base for materials used in structures, the effects of gravity, weight loading, etc. are sufficient to predict outcomes to produce sound structures. As with climate, a computer model of solar functions involves variables and cycles that are not known or are not known with sufficient precision for the model to be a valid predictor of outcomes.

Gary Strand

It would be nice to have 1km x 1km x 10m resolution weather data for the entire atmosphere and ocean, but that’s not ever going to happen. Blaming models for the “GI” part of “GO” isn’t fair.
It’s also unfortunate that the technological development required to have computers and satellites and good earth observing systems also seems to have required the use of energy sources that are altering the climate of the planet.

MarkB

Regarding those who badmouth mathematical models: how about you go learn to write one, and then come back to us and share your expertise. Until you do, you’re no better than the sports fans who call into talk radio every day and complain about a decision a manager made during a baseball game. Everone’s a baseball expert – including Joe the Hostess Twinkies delivery van driver.

red432

A little modesty and careful qualifications would be nice.
Some time back I read in the Economist that some computer
guys were working on “modelling” a whole nematode.
I was amazed that the Economist folk just bought this
hook line and sinker. At the current state of understanding
no one knows how to model the folding of a single protein
given any amount of computing power — not to mention
how it behaves in an organism. I’m guessing the
nematode model was an utter waste of time (except for
extracting money from some grant giver).
Maybe the sunspot simulators could say the are not “modelling sunspots” but
simulating our current hypotheses about sunspots in order to see
if they seem to reasonably reflect reality.

JamesD

So let me get this straight. This simulation shows the structure of a sun spot on the order of magnitude of the sun, but it is not perfect. And it takes a week to solve on a super computer. Now imagine simulating this every second, for years and years, and you get an idea of the computing power it would take to model the Earth’s climate. Compute climate models are a joke. They are useless.

JamesD

“order of magnitude of the EARTH”, correction

Gary Strand

JamesD, would you recommend all climate modeling efforts be ended and their funding zeroed?

MikeW

As a programmer myself, I can just imagine the amount of effort, debate, testing and retooling that must have gone into each aspect of this project to coax the simulation to a point where its predictive output begins to track actual observations of a recorded event. Such staggering complexity.
But then, how humiliating would it be to find that all your work is only good for studying something that the Sun used to do. Ouch!

rbateman

The spot simulation needs fractalization, which is again more iterative load.
Like fusion, it’s 30 years away.

Kath

Gary Strand (18:37:56) :
“Do you still believe models are worthless?”
Gary, those FEA programs that are used to model engineering structures are checked and verified against known test models and small scale experiments to ensure that the results they produce are consistent. They go through extensive quality control to ensure consistency, and even then, the resultant models have to be checked for anomalies or unexpected behaviour that could be caused by incorrect constraints, boundary conditions, element types or other factors. Designers & engineers who use these programs also apply appropriate safety factors depending on application. Where appropriate, scale or partial full scale models may be tested and supplemented with theoretical calculations.
Engineering models cannot be compared, in any way, to climate models or the sunspot models in this article.