Detecting sunspots before they form allows for better space weather forecasting

From Stanford University

New method detects emerging sunspots deep inside the sun, provides warning of dangerous solar flares, say Stanford researchers

Sunspots spawn solar flares that can cause billions of dollars in damage to satellites, communications networks and power grids. But Stanford researchers have developed a way to detect incipient sunspots as deep as 65,000 kilometers inside the sun, providing up to two days’ advance warning of a damaging solar flare.

Above: Movie showing the detected travel-time perturbations before the emergence of active region 10488 in the photosphere. The first 10 seconds of the movie show intensity observations of the Sun. The intensity later fades out and the photospheric magnetic field is shown. In the next 20 seconds, we zoom in to a region where a sunspot group would emerge. The upper layer shows magnetic field observations at the surface and the lower layer shows simultaneous travel-time perturbations, detected at a depth of about 60,000 km. After the emergence, intensity observations show the full development of this active region, until it rotates out of view on the west solar limb. (movie made by Thomas Hartlep, converted for YouTube by Anthony Watts)

Stanford researchers have found a way to detect sunspots such as these two days before they reach the surface of the sun.

BY LOUIS BERGERON

Viewed from the technological perspective of modern humans, the sun is a seething cauldron of disruptive influences that can wreak havoc on communication systems, air travel, power grids and satellites – not to mention astronauts in space.

If disruptions such as solar flares and mass eruptions could be predicted, protective measures could be taken to shield vulnerable electronics before solar storms strike.

Now Stanford researchers have developed a method that allows them to peer deep into the sun’s interior, using acoustic waves to catch sunspots in the early stage of development and giving as much as two days’ warning.

Sunspots develop in active solar regions of strong, concentrated magnetic fields and appear dark when they reach the surface of the sun. Eruptions of the intense magnetic flux give rise to solar storms, but until now, no one has had luck in predicting them.

“Many solar physicists tried different ways to predict when sunspots would appear, but with no success,” said Phil Scherrer, a professor of physics in whose lab the research was conducted.

The key to the new method is using acoustic waves generated inside the sun by the turbulent motion of plasma and gases in constant motion. In the near-surface region, small-scale convection cells – about the size of California – generate sound waves that travel to the interior of the sun and are refracted back to the surface.

The researchers got help from the Michelson Doppler Imager aboard NASA’s Solar and Heliospheric Observatory satellite, known as SOHO. The craft spent 15 years making detailed observations of the sound waves within the sun. It was superseded in 2010 with the launch of NASA’s Solar Dynamics Observatory satellite, which carries the Helioseismic and Magnetic Imager.

Using the masses of data generated by the two imagers, Stathis Ilonidis, a Stanford graduate student in physics, was able to develop a way to reduce the electronic clutter in the data so he could accurately measure the solar sounds.

The new method enabled Ilonidis to detect sunspots in the early stages of formation as deep as 65,000 kilometers inside the sun. Between one and two days later, the sunspots would appear on the surface. Ilonidis is the lead author of a paper describing the research, published in the Aug. 19 edition of Science.

The principles used to track and measure the acoustic waves traveling through the sun are comparable to measuring seismic waves on Earth. The researchers measure the travel time of acoustic waves between widely separated points on the solar surface.

Above: Movie showing the detected travel-time perturbations during the emergence of active region 11158. The first 12 seconds of the movie show photospheric intensity observations (orange color) of the region, and travel-time perturbations detected at a depth of about 60,000 km (blue-red color). The movie then shows sunspots (blue and orange) on the solar surface and coronal loops (light green) observed by SDO/AIA. (movie made by Thomas Hartlep and Scott Winegarden, converted for YouTube by Anthony Watts).

“We know enough about the structure of the sun that we can predict the travel path and travel time of an acoustic wave as it propagates through the interior of the sun,” said Junwei Zhao, a senior research scientist at Stanford’s Hansen Experimental Physics Lab. “Travel times get perturbed if there are magnetic fields located along the wave’s travel path.” Those perturbations are what tip the researchers that a sunspot is forming.

By measuring and comparing millions of pairs of points and the travel times between them, the researchers are able to home in on the anomalies that reveal the growing presence of magnetic flux associated with an incipient sunspot.

They found that sunspots that ultimately become large rise up to the surface more quickly than ones that stay small. The larger sunspots are the ones that spawn the biggest disruptions, and for those the warning time is roughly a day. The smaller ones can be found up to two days before they reach the surface.

“Researchers have suspected for a long time that sunspot regions are generated in the deep solar interior, but until now the emergence of these regions through the convection zone to the surface had gone undetected,” Ilonidis said. “We have now successfully detected them four times and tracked them moving upward at speeds between 1,000 and 2,000 kilometers per hour.”

One of the big goals with forecasting space weather is achieving a three-day warning time of impending solar storms. That would give the potential victims a day to plan, another day to put the plan into action and a third day as a safety margin.

Funding for the research came from NASA’s Living with a Star program.

###

Alexander Kosovichev, a senior research physicist in Scherrer’s research group, also participated in the research.

 

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46 thoughts on “Detecting sunspots before they form allows for better space weather forecasting

  1. It’s a pity they invented this method just before the total disappearance of sunspots. Well, you can’t have everything.

  2. they said they detected 4 so far. I wonder how accurate they are? How many do they expect to miss? How many false alarms?

  3. also, how long does it take them to do the calculations? Can they do this in real time, and really give a day or two of warming, or is that only when they have as long as they like to look over historical data?

  4. Can anyone help find the empirical evidence for Global warming?
    With the recent spate of good papers on global warming I thought it would be interesting to compile a list of all the empirical (not model based) evidence both pro and anti manmade global warming with a particular emphasis on the positive feedback necessary for the doomsday scenario.
    My hunch was that the weight of evidence might be anti, but I was surprised to find great problems finding much if anything to put in the “pro” category. I’ve searched the internet high and low and even asked the alarmists on wikipedia but I’m still woefully short of anything much pro warming.
    Seriously, if anyone can point me in the direction of any evidence based paper backing up manmade global warming I’d welcome a link … and of course I’ve probably forgotten some of the anti papers so help would be welcome there too. list

  5. At last, some seemingly useful research from NASA. Well done to those involved.
    Now we need more research funds to prove this is caused by AGW.

  6. My last line was supposed to show (sarc) tags as I do not wish to denigrate the good work done by these guys, just my disgust with others who try to make every observation a result of AGW

  7. With respect, I don’t see how an extra days notice of sunspots emerging on the Sun’s surface is a whole lot of use when it comes to predicting the powerful flares that have the potential to cause damage to our infrastructure.
    The large sunspots from which these flares tend to emanate, like group 1271 at the moment, can stay around for weeks with the potential to fire off strong flares, but no-one seems to know exactly when, or even if, this potential will be realised. How does this help?
    Paging Dr. Svalgaard……

  8. Anything is possible says:
    August 19, 2011 at 3:38 pm
    With respect, I don’t see how an extra days notice of sunspots emerging on the Sun’s surface is a whole lot of use when it comes to predicting the powerful flares that have the potential to cause damage to our infrastructure. […]
    Paging Dr. Svalgaard……

    I just this morning attended a meeting at Stanford and listened to Ilonidis. The result is a nice piece of work, but there is more to do before it can used in operational forecasting. The calculations are moderate [a few hours on a single PC] and can be speeded up a lot [it is done in the interpreted language IDL], so should not be a problem for real-time prediction. More troubling is that they knew where to look in getting the correspondence. Since the area used for the analysis is small, 1/100 to 1/1000 of the visible disk, you must cover about half of all possible such areas in order to find an emerging flux. This could be done by running several PCs in parallel, so is not fatal, just an obstacle to be overcome. The question of false alarms need more cases to be answered. So let us give them a break on that. The question of the utility of a day or two warning is more problematic. A large and complex sunspot is always a good candidate for CMEs and flares, but these occurs a few days into the evolution of the spot anyway, so we do already have some warning. What we really want to do is to detect these merging spots at the East limb [the study used spots in a trip 45 degrees wide around Central Meridian], but this is not [yet?] possible because of the noise involved. Again, let us let them work at it.

  9. Leif Svalgaard says:
    August 19, 2011 at 6:30 pm

    The, perhaps obscure, length unit ‘Mm’ is a Megameter = 1000,000 meter = 1000 km. The solar diameter is some 1400 Mm.

  10. Thanks for the clarification, Leif.
    Looks like another case of the headline-writers running ahead of the science. Seems to happen a lot these days (:-

  11. Anything is possible says:
    August 19, 2011 at 7:35 pm
    Looks like another case of the headline-writers running ahead of the science.
    The science has great promise. Just needs a bit more work. Immediate benefits include measuring the ascent rate.

  12. Leif Svalgaard says:
    August 19, 2011 at 6:32 pm
    Leif Svalgaard says:
    August 19, 2011 at 6:30 pm

    The, perhaps obscure, length unit ‘Mm’ is a Megameter = 1000,000 meter = 1000 km. The solar diameter is some 1400 Mm.
    ======
    Now, you are just buying time and confusing me with measurements.
    Instead of telling me to SHUT UP, so you can think for one minute.
    I know the feeling.

  13. Why would some spots take much longer to rise, and end up weaker and shorter lived at the surface?

  14. Now Stanford researchers have developed a method that allows them to peer deep into the sun’s interior, using acoustic waves to catch sunspots in the early stage of development and giving as much as two days’ warning.

    Huh? How do you peer deep into the interior of a solid iron globe? Where’s Oliver when you need him?

  15. rbateman says:
    August 20, 2011 at 1:05 am
    Why would some spots take much longer to rise, and end up weaker and shorter lived at the surface?
    A magnetic field has a pressure on its own which means that a gas parcel with a magnetic field needs less gas to have the same pressure as its surroundings. This means that it weighs less and is thus buoyant. The weaker the field, the less buoyant the spot is, and thus the longer it takes to rise and the easier it is to be chipped away at once at the surface.

  16. Gary Swift says:
    August 19, 2011 at 3:30 pm
    they said they detected 4 so far. I wonder how accurate they are? How many do they expect to miss? How many false alarms?

    My thoughts exactly. An alarm that is constantly sounding is worse than no alarm at all! It is a constant distraction and can cause a real alarm to be ignored.
    This is something the AGW advocates have yet to learn, because they have no operational experience. GK

  17. G. Karst says:
    August 20, 2011 at 7:41 am
    An alarm that is constantly sounding is worse than no alarm at all! It is a constant distraction and can cause a real alarm to be ignored.
    From the paper you can see that there is very little chance that there will be a false positive [alarm when there is nothing]. The issue is rather one of false negatives [missing spots], because we don’t know precisely where to look so will have to look everywhere [hundreds of probes every few hours].

  18. Leif Svalgaard says:
    August 19, 2011 at 6:17 pm
    What we really want to do is to detect these merging spots at the East limb [the study used spots in a trip 45 degrees wide around Central Meridian], but this is not [yet?] possible because of the noise involved.

    Why the particular interest in the “east limb”? Are the emerging spots less apparent there?

  19. Bill Parsons says:
    August 20, 2011 at 10:54 am
    Why the particular interest in the “east limb”? Are the emerging spots less apparent there?
    Spots are harder to see at the limbs because of foreshortening. If the spot emerges near the center of the disk we can see the first hints the usual way in any case. These are harder to see at the limb. We are less interested in the West limb because the spot is rotating out of view there.

  20. Leif Svalgaard says:
    August 20, 2011 at 6:14 am
    What does this say, if anything, about the L&P effect, and do we know if there are gas parcels that dissipate before they reach the surface?

  21. rbateman says:
    August 20, 2011 at 12:09 pm
    What does this say, if anything, about the L&P effect, and do we know if there are gas parcels that dissipate before they reach the surface?
    That we don’t know [yet]. We can, however, use the method on MDI data since 1996 so should be able to know. Lots of things to investigate. Stay tuned 🙂

  22. ‘Because you can’ or ‘because it is there’ was, historically, motivation enough for scientific inquiry. I note that there seems to always have to be a practical application (substitute apology) tacked on to scientific research now. I know where this came from. Many years ago, I worked for government and one research branch – the Geological Survey of Canada- were instructed by the deputy minister (political master) to provide economic justification for the geological, geophysical, geochemical, mineralogical… work they were budgeting for. This lead to the inevitable screw-ups of the economically illiterate forced to give a reason for doing the work. One specialist in the petrology of granites offered that the intrusives he was studying were rich in potash feldspars (the pink silicate mineral in tombstones) and could be a source of potash fertilizer – seemingly unaware: 1) that Canada is the world’s largest producer of potash fertilizers from readily soluble KCl salts that underlie most of the southern half of Saskatchewan out west, and 2) Wresting the potash from feldspars would be a very desperate expensive affair. The economically illiterate deputy minister, however, signed off on the budget.

  23. @Gary Pearse says:
    August 20, 2011 at 2:04 pm
    (We)”were instructed by the deputy minister (political master) to provide economic justification for the geological, geophysical, geochemical, mineralogical… work they were budgeting for.”
    Such is the Way of the West. I understand the East has a much more objective approach; one that can prove fatal to non-achievers. Ya’ just can’t win. Life’s a beach, no matter who you work for.

  24. Leif Svalgaard says:
    August 20, 2011 at 4:39 pm
    Pascvaks says:
    August 20, 2011 at 3:42 pm
    Life’s a beach, no matter who you work for.
    Nothing wrong in lying on the beach watching the bitches go by…
    I guess it would be stating the obvious that it must not have occurred to you that some readers might be offended to be referred to as “bitches”.

  25. Daryl M says:
    August 20, 2011 at 4:52 pm
    I guess it would be stating the obvious that it must not have occurred to you that some readers might be offended to be referred to as “bitches”.
    My female dog doesn’t read WUWT

  26. Try listening to or reading lyrics of popular C-Rap, and you’ll be a bit less sanguine about the term. Much as I am anti-PC, that debasement of females is really offensive.

  27. Brian H says:
    August 20, 2011 at 6:37 pm
    Try listening to or reading lyrics of popular C-Rap, and you’ll be a bit less sanguine about the term. Much as I am anti-PC, that debasement of females is really offensive.
    Indeed it is. The point was that the correct ‘quote’ should not have been ‘life’s a beach’.

  28. Leif Svalgaard says:
    August 20, 2011 at 8:03 pm
    Brian H says:
    August 20, 2011 at 6:37 pm
    Try listening to or reading lyrics of popular C-Rap, and you’ll be a bit less sanguine about the term. Much as I am anti-PC, that debasement of females is really offensive.
    Indeed it is. The point was that the correct ‘quote’ should not have been ‘life’s a beach’.
    Then why not say that instead of making a derrogatory remark like a rapper punk? I suppose for someone such as yourself who is always right, it wouldn’t occur to you to retract the comment and apologize to anyone who might have been offended.

  29. Hummmmm… this is getting a might… wait while I still have the point in mind I came back to deposit – “beach” is poetic, it says more than most think at first blush, it also says more than second blush, or as a punny. There really are more similarities for “beach”, as a metaphore for “life”, than you might suppose; but you must have some experience on a beach, there’s just no substitute; it can’t be done on the web; of course you could, given enough time on the web, come out and say that “life’s a web”, that would be OK. Never mind! Back to “this is getting a might”.. I’m guessing, of course, how could it be otherwise, that the objection to someone’s using the traditional English for a female dog as a pun is somehow a no-no in this day and age. What!!!! Today???? The Age of Dirt? The Age of Stupidity??? The Age of Meaningless Tripe??? You can’t be serious! What planet are you guys from? Have you been locked in a time capsule for the past 30 years? Who’s the president of Mexico? –Wait! Don’t answer that! Big Sis might think I’m trying to ‘Out You’ and put me on a Watch List. Better shut up. Said too much. Sorry! Forget everything after “Hummmmmmm..”. Please? Pretty please????

  30. Daryl M says:
    August 20, 2011 at 10:24 pm
    it wouldn’t occur to you to retract the comment and apologize to anyone who might have been offended.
    sure, let all the offended accept this. WUWT is a beach, sometimes.

  31. Geesh, in trying to stay on the topic..
    Nothing new under the sun. (surface that is)
    And what would have transpired here if he would have said, “[]”
    [That. Robt]
    .

  32. Leif is working from a long tradition. Archaeologists uncovering early shards of pottery and other remains on the beaches of Vineland think Vikings were actually some of the earliest gangster rappers. This is born out in long passages of the Poetic Eddas where Thor really “puts the hammer down”.
    These are little-known facts. Perhaps best left that way.
    Word.

  33. Leif Svalgaard says:
    August 19, 2011 at 7:46 pm
    The science has great promise. Just needs a bit more work. Immediate benefits include measuring the ascent rate.

    I’ll say. What was the uncertainty on ascent rate prior to this work Leif?

    🙂

  34. tallbloke says:
    August 22, 2011 at 12:07 pm
    I’ll say. What was the uncertainty on ascent rate prior to this work Leif?
    There really was no uncertainty with this as the internal structure of the sun is well-known [we measure it with helioseismology and it matches our theoretical models very well]. What is needed to calculate the ascent is a value for the magnetic field which is [was!] unknown until we observe it at the surface. We can now turn the equations around and use the measured rate to calculate the magnetic field at depth.

  35. tallbloke says:
    August 22, 2011 at 1:00 pm
    some kind of boundary there
    No boundary.
    or is that the level the particular instruments used can best resolve to?
    There is a trade-off between signal and depth. Greater depth = smaller signal, so 60 Mn is where things work best with that particular method. But there may be variants that work better, this is what I meant by ‘more work to be done”.

  36. Leif,
    What do these instruments actually “see”? What physical properties do sound waves manifest that we can pick up on from out in space?
    I understand the principle of sound waves revealing different density layers, at least here on earth. But how are these reflections captured inside the sun?

  37. Bill Parsons says:
    August 22, 2011 at 2:19 pm
    What do these instruments actually “see”? What physical properties do sound waves manifest that we can pick up on from out in space?
    If you have an earthquake, the sound waves from the quake spreads out in a circular manner. The waves move the material. We can pick up these movements with a seismograph. On the sun there are millions of ‘sun quakes’ going off all the time [essentially the turning over of convection cells] so the sun’s material moves [‘bobs’] up and down as the waves travel. The sound waves also travel downwards. Because the density increases with depth, the wave speed changes and the waves are refracted upwards again to reach the surface at some distance from the source, so the movements in a ring around the source are correlated. We measure the up-down bobbing by looking at the light from a small patch of the surface. If the material is going up [towards us] the light is blue-shifted [by the Doppler effect]; if moving away, the light is red-shifted. In this way we can detect movements as small as a few millimeters and thus keep track of where the wave rings are. The travel time depends on the density of the matter along the wave trajectory and this is what we found is varying underneath a sunspot.

  38. Leif Svalgaard says:
    August 22, 2011 at 2:44 pm
    In this way we can detect movements as small as a few millimeters and thus keep track of where the wave rings are.
    That is per second. The amplitude of the waves can be very large, several hundred kilometers and the waves are readily observable.

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