Giant Convection Cells Found on the Sun

NASA’s Dr. David Hathaway has just published a new paper, and it has advanced solar science. He’s found something they’ve been looking for a long time; long lived convection cells. Massive, long-lasting plasma flows 15 times the diameter of Earth transport heat from the sun’s depths to its surface, according to a study in the Dec. 6 Science. The finding supports a decades-old explanation of why the sun rotates fastest at its equator.

gp_hathaway1HR_supergranules

BIG SOLAR CELLS Giant, long-lived convective structures (left) move plasma on the sun’s surface. Earlier observations found only much smaller plasma flows covering the sun (right). In these illustrations, blue indicates plasma flowing east to west; red indicates west to east.

Convection motions within the Sun transport heat from its interior to its surface. The hot regions are seen as granular (∼1000 kilometers across) and supergranular (∼30,000 kilometers across) cells in the Sun. Using data from the Helioseismic Magnetic Imager on the Solar Dynamics Observatory, Hathaway et al. (p. 1217) found evidence for even larger cells that have long been predicted by theory but not unambiguously detected. The flows associated with these giant cells transport angular momentum toward the equator and are important for maintaining the Sun’s equatorial rotation.

Video follows: 

GO WITH THE FLOW  Long-lasting plasma flows appear in red and blue in this animation, which portrays data from four solar rotations. Some flows persist for several months; these patterns are especially visible near the sun’s north pole. Scientists think these flows keep the sun’s equator rotating faster than its poles.

The paper:

Giant Convection Cells Found on the Sun

David H. Hathaway1,*,Lisa Upton2,3,Owen Colegrove4+ Author Affiliations


  1. 1NASA Marshall Space Flight Center, Huntsville, AL 35812, USA.

  2. 2Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235, USA.

  3. 3Department of Space Science, University of Alabama in Huntsville, Huntsville, AL 35899, USA.

  4. 4Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA.

Heat is transported through the outermost 30% of the Sun’s interior by overturning convective motions. These motions are evident at the Sun’s surface in the form of two characteristic cellular structures: granules and supergranules (~1000 and ~30,000 kilometers across, respectively). The existence of much larger cells has been suggested by both theory and observation for more than 45 years. We found evidence for giant cellular flows that persist for months by tracking the motions of supergranules. As expected from the effects of the Sun’s rotation, the flows in these cells are clockwise around high pressure in the north and counterclockwise in the south and transport angular momentum toward the equator, maintaining the Sun’s rapid equatorial rotation.

Materials/Methods, Supplementary Text, Tables, Figures, and/or References

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61 thoughts on “Giant Convection Cells Found on the Sun

  1. “Giant convection cells found on the sun”

    So THAT’S where the heat went missing……………………

    Crikey…..

  2. Does this change Leif’s statement that the heat from the center of the sun ‘takes 100,000 years to make it from the core to the top’?

  3. In the top figure (2010/1996), were they measured by the same instruments?

    Interesting because it would cast doubt on the traditional (1996) view of ‘photons’ being individual random events. By 2010, energy can congregate at the surface.

    Lief – correct me please.

  4. Photons are not plasma. Photon drift rate, from absorption, re-emission, re-absorption takes a very long time, on the order of 100,000 years. Plasma is ionized and massy particles, convection of which is the Sun’s major heat transport mechanism.

  5. I’ve been educated for decades by seeing photograph-like images representing the Sun’s surface as quite granular. Time to revise that thought, I guess.

  6. The light does take thousands of years to make it through the core area and into the convection zone, since the Sun is pretty much opaque to photons.

  7. The image labeled “May 26, 1996″ above is not showing zonal [east-west] flows, as stated in the caption. Instead, it shows the component of the photospheric Doppler velocity projected into the line of sight, after some temporal averaging. The temporal averaging brings out the horizontal flow pattern of supergranulation, a convection pattern having an approximate length scale of 20-30 Mm. The signal is primarily horizontal [parallel to the photospheric surface], which is why the signal is reduced near disk center. I presume the Doppler velocity data used for this image were originally taken by the MDI instrument on SOHO.

  8. “Massive, long-lasting plasma flows 15 times the diameter of Earth …” Wow. Hadley, Ferrel – yes, and Polar ( :-) ) – eat your hearts out. Leif has something to dream on tonight.

  9. DD More says:
    December 5, 2013 at 1:00 pm
    Does this change Leif’s statement that the heat from the center of the sun ‘takes 100,000 years to make it from the core to the top’?
    No, as it takes that long [or a bit longer] to get out of the core which is pretty opaque. Then the transport through the outermost 30% of the Sun is swift [weeks].

    3×2 says:
    December 5, 2013 at 1:28 pm
    In the top figure (2010/1996), were they measured by the same instruments?
    No, and they don’t show the same thing. Poor illustration…

  10. Heat is transported through the outermost 30% of the Sun’s interior by overturning convective motions.
    Key question is: are these cells associated with the generation of solar magnetic field.
    If so, discovery would support Dr. Hathaway’s hypothesis that the solar dynamo is located deep in the solar interior..
    I believe that Dr. Svalgaard holds opposite view, i.e. shallow location for the solar dynamo.

  11. its clear to me that the count of convection cells in the Northern hemisphere + log(convection cells in the southern hemisphere) * Jupiter’s mass +2.1365 will correlate with
    something in the climate.

    cyclomaniacs unleash your fevered brains

  12. vukcevic says:
    December 5, 2013 at 2:46 pm
    If so, discovery would support Dr. Hathaway’s hypothesis that the solar dynamo is located deep in the solar interior..
    The cells are in the outermost layers and Hathaway believes in a shallow dynamo.

    Robertvd says:
    December 5, 2013 at 2:46 pm
    How big is exactly the nuclear reactor core of the sun ?
    The core extends 25% of the radius, but outside the core is a stable regime with no convection where heat transport is slow by radiation. The convection zone begins at about 70% of the radius and the heat transport is fast by convection

  13. Mr Mosher,

    it is clear to me that the number of planetary orbits around the Sun + the number of [non-existent] Medicine Moons circling Jupiter * Sun’s mass + 3.14159 will have something to do with the [discredited] Godless heresies of Copernicus and Galileo…

    Heliocentrics unleash your fevered brains…

  14. Robertvd says: December 5, 2013 at 2:46 pm “How big is exactly the nuclear reactor core of the sun ?” About 4 x 10^26 Watts. For numerological comparison, Avogadro’s Number Na is 6.02214129 x 10^23

  15. Leif,
    First off, thanks for your input on all subjects solar. Your comments are very much appreciated.

    Is there any theoretical linkage between these large scale convection patterns and the effect Livingston and Penn is observing? Is it possible the size of these convection cells change from solar cycle to solar cycle? Since there appears to be little or no long term varience in the Ap measurements (other than the 11 year cycle) would changes in the convection pattern account for the various solar minimums (Maunder, Dalton…)?

  16. phager says:
    December 5, 2013 at 5:54 pm
    Is there any theoretical linkage between these large scale convection patterns and the effect Livingston and Penn is observing? Is it possible the size of these convection cells change from solar cycle to solar cycle?
    All good questions. If I had all the answers, I would be on my to Stockholm to pick up my Nobel Prize :-)

    My own take is the those giant cells are connected with the Solar Sector Structure http://www.leif.org/research/Solar%20Sector%20Structure.pdf and with the Hale Boundaries http://www.leif.org/research/Hale-Flares.pdf but all this is still in flux. Expect rapid progress though as we collect more SDO data.

  17. lsvalgaard says:

    December 5, 2013 at 6:02 pm

    My own take is the those giant cells are connected with the Solar Sector Structure http://www.leif.org/research/Solar%20Sector%20Structure.pdf and with the Hale Boundaries http://www.leif.org/research/Hale-Flares.pdf but all this is still in flux. Expect rapid progress though as we collect more SDO data.
    —-

    Your getting really good at this Dr. S.. Your answering my questions before I can ask them. Figured you have probably been watching the sector structures for years..

    Thanks

    Rapid progress in lots of areas.. like were on the verge.. all the time..

  18. lsvalgaard says: December 5, 2013 at 3:00 pm
    … The core extends 25% of the radius, but outside the core is a stable regime with no convection where heat transport is slow by radiation. …

    I’ve always seen the diagrams where there is a large region with straight arrows labelled radiation, which I’ve taken to mean the region is transparent and the energy is zipping across it to the convective zone at the speed of light. So how is this slow transport? Slow would need a ridiculously high refractive index.

    Please elucidate.

  19. lsvalgaard says: December 5, 2013 at 8:54 pm

    So translucent instead of transparent, with effective refractive index of 7.5 x 10^12, give or take an order of magnitude. And we thought ‘slow glass’ was just science fiction. Thanks

  20. Ha! I, in my goddess wisdom, trump any notion of planetary * solar = T. I have known for years that my sleep habits correlate with the dawn and my hot flashes have caused the recent decade long rise in temperatures. Because I am now on the other side of those, of course there is a pause. Send sacrifices. My cave door is always open to those bearing gifts.

  21. “Mike McMillan says: December 5, 2013 at 8:42 pm

    lsvalgaard says: December 5, 2013 at 3:00 pm
    … The core extends 25% of the radius, but outside the core is a stable regime with no convection where heat transport is slow by radiation. …

    I’ve always seen the diagrams where there is a large region with straight arrows labelled radiation, which I’ve taken to mean the region is transparent and the energy is zipping across it to the convective zone at the speed of light. So how is this slow transport? Slow would need a ridiculously high refractive index.

    Please elucidate.”

    Whatever for?
    You’re the one spinning fantasy and then asking us to spend time trying to explain nuclear reactions, plazma and heat; heat, Got that? How does index of refraction have anything to do with heat?

  22. Thanks Dr. Leif for your comments and the links you provided.
    Do you have any comments on the possible influence of solar radiations on the decay rates of various elements on Earth?
    (here are the links:
    /1/ description,

    http://news.stanford.edu/news/2010/august/sun-082310.html

    /2/ attempt to answer,

    http://arxiv.org/abs/0808.3283)

    I believe there is an important component of “weak nature” (in the sense of
    electro-weak unified field) in the solar radiations, that *could be* connected with the presence of the so called “dark matter” in the Sun.

  23. phager says:December 5, 2013 at 5:54 pm
    “Is there any theoretical linkage between these large scale convection patterns and the effect Livingston and Penn is observing? Is it possible the size of these convection cells change from solar cycle to solar cycle? Since there appears to be little or no long term varience in the Ap measurements (other than the 11 year cycle) would changes in the convection pattern account for the various solar minimums (Maunder, Dalton…)?”
    I don’t have the answers for your questions more than Leif does, but in an attempt to elaborate we may say that convection depends on temperature gradients and the gradients must naturally change during solar cycles.
    The ssn count seems to be closely connected with the ap/aa indices therefore there must be an oscillation in the convection cells too, related with the cycles.
    The LP effect would correspond to an extreme version of these oscillations.
    One thing that passed through my mind is, the existence of convection cells could possibly produce also blocking of “normal circulation” due to differences of energy, as we have on Earth, and this could be connected with the ssn count.
    The problem is, what processes cause the gradients of temperature and their variations along the various cycles?

  24. I need a education (partially please) the video shows the sun turning at a speed that I think may have been sped up, the rolling dates on the video show the sun turning around (to me anyway) way too fast. I thought it took 28? days for a complete turn, not at the speed the video shows . Am I wrong? It is confusing, sorry. I also wonder why the center part or the image of the sun (1996 right hand SOHO image) seems to be blurred, I wonder if that may be a factor of that part of the Sun is a lot closer to the camera on SOHO and more intense?.

  25. tobias says:
    December 5, 2013 at 10:32 pm
    …………..
    Sun rotates every 25 days at the equator and in excess of 30 at the poles. If you stop the video, take a marker at lower mid latitude at left edge it takes 13 days to hit the opposite,

  26. Dr. S.Hathaway believes in a shallow dynamo.

    It is good to know that he has accepted more realistic approach:
    Hathaway: Our measurements show the largest cells clearly moving equatorward at depths below 35 Mm – the base of the Sun’s surface shear layer. This surprisingly shallow return flow indicates the need for substantial revisions to solar/stellar dynamo theory..

  27. It’s odd that the ‘earlier observations date from 1996 when WUWT published this article just last year.

    http://wattsupwiththat.com/2012/07/09/weak-solar-convection-approximately-100-times-slower-than-scientists-had-previously-projected/

    ““Our current theoretical understanding of magnetic field generation in the Sun relies on these motions being of a certain magnitude,” explained Shravan Hanasoge, an associate research scholar in geosciences at Princeton University and a visiting scholar at NYU’s Courant Institute of Mathematical Sciences. “These convective motions are currently believed to prop up large-scale circulations in the outer third of the Sun that generate magnetic fields.”

    “However, our results suggest that convective motions in the Sun are nearly 100 times smaller than these current theoretical expectations,” continued Hanasoge, also a postdoctoral fellow at the Max Plank Institute in Katlenburg-Lindau, Germany. “If these motions are indeed that slow in the Sun, then the most widely accepted theory concerning the generation of solar magnetic field is broken, leaving us with no compelling theory to explain its generation of magnetic fields and the need to overhaul our understanding of the physics of the Sun’s interior.”

    No ‘settled science here’, clearly.

  28. I don’t understand how the “transportation of angular momentum from the centre” makes the equator spin faster. Surely it would have the opposite effect.

    As anyone knows who watches ice skaters and observes the rotation increase when the arms come in and decrease when the arms goes out, angular velocity decreases with radius of spin while conserving angular momentum. If angular momentum is to be conserved in the sun, then as you pull material out to the equator its angular velocity would need to decrease.

  29. Leif,
    This all looks like we have discovered better detail on the inner workings of the watch. As an engineer, I ask, does this knowledge help us to know what time it is? Is there any bottom, bottom line here relative to new understanding, changes in general solar theory?

  30. Jim G says:
    December 6, 2013 at 8:35 am
    Is there any bottom, bottom line here relative to new understanding, changes in general solar theory?
    Not really, as those cells were expected [have been for more than 40 years]. The discovery places constraints on the details. And that we need in order to predict better.

  31. @ Vince Causey : Don’t quote me on this but I believe the difference is due to the sun being fluid not solid so the behavior is different than the skater analogy.

  32. I put these 3 images together (MDI con, Solar cells & magnetogram)

    http://www.vukcevic.talktalk.net/sun.htm

    Regrettably, visually I can’t see any great relevance to the formation of sunspots or magnetic field distribution, hopefully Hathaway & co may find and explain the link if there is one (surely must be one lurking in the undergrowth)

  33. These guys sound more like the global warming pseudo-scientists every day. They try to prove theories that have already been falsified instead following the scientific method. I don’t understand why people so skeptical of the global warming pushers are so uncritical of solar theory pushers.

  34. Hi Leif,

    Do these convection zones have any relationship to the filaments that make flares? Also do they have any connection to the formation of spots or their complexity?

    Jim Arndt

  35. Mark says:
    December 6, 2013 at 10:28 am
    “I don’t understand why people so skeptical of the global warming pushers are so uncritical of solar theory pushers”

    Because solar theory pushers, as you call them, are not demanding billions of dollars in taxes from everyone and have no agenda to control people.

  36. Leif,
    I’ve wondered about the long term radiative travel time through the core. While that very long travel time appears true for radiative energy, it would seem that a change in energy production (very small of course) could result in a very short term change in hydrostatic equilibrium that would ripple through far far faster and change the size of the Sun’s radiative surface and hence its total radiative output. After all, one sees variable stars that vary rapidly (hours to weeks) with serious amounts of power variation that can’t be waiting hundreds of thousands of years for the generated power variations to exit the core.
    However, I don’t see any mention of this mechanism in explanations of time lag – which makes me think it is not considered by the experts to be a theoretically valid mechanism – at least where the Sun is concerned. Is it?

    Happy holidays to you and Vera.

  37. cba says:
    December 8, 2013 at 4:09 am
    it would seem that a change in energy production (very small of course) could result in a very short term change in hydrostatic equilibrium that would ripple through far far faster and change the size of the Sun’s radiative surface and hence its total radiative output.
    Sound waves do travel through the interior in hours, but do not really disturb the hydrostatic equilibrium any more than idle chatter of people in a room does. The problem with variation in energy production is oe of chicken and egg. Energy production controls temperature, but is itself very temperature sensitive. The pulsations of other stars is controlled by changes in opacity but conditions in the Sun are not conducive to that mechanism, so there would be no reason to expect such changes [and such pulsations are not observed]. The issue is one of ‘restoring force’, which could be pressure [giving rise to so-called p-mode oscillations], or gravity [giving rise to so-called g-modes, which have not been firmly observed – in spite of some claims of the opposite]. In any case, lags imposed would be short [hours].

  38. vukcevic says:

    December 6, 2013 at 9:42 am

    I put these 3 images together (MDI con, Solar cells & magnetogram)

    http://www.vukcevic.talktalk.net/sun.htm

    Regrettably, visually I can’t see any great relevance to the formation of sunspots or magnetic field distribution, hopefully Hathaway & co may find and explain the link if there is one (surely must be one lurking in the undergrowth)
    ———–
    You must of forgot about SDO imagery.
    From the link, input for start/end date 2010-06-08, then chose imagery type 193, from the drop down menu. The N/S angle is a little N ward in the convection construction image from our article above, but I think you might see some of the flows in the imagery from SDO…

    http://iris.lmsal.com/iristoday/

    Note link is for the new “IRIS” eye on the sun, but has the SDO also. There will be a presentation at AGU for IRIS.

    If Dr. S. is still around here somewhere. When you started your sectors watch 46 years ago, I was only 10. Good precursor for anyone might be some of your earlier articles on sectors and boundaries. Told myself in around 09 that I would have to read sectors and boundaries again. And now we have, “FLARING SOLAR HALE SECTOR BOUNDARIES,” along with the even newer, convection cells, complete with models.

    http://www.leif.org/research/Hale-Flares.pdf

    Is there a cycle dependency, in timing or strength, on whether there will be 2 or 4 warps in the heliocurrent sheet? It is wavey er during lower solar cycles because..

  39. Some might use slightly different terminology but this seems relative to sectors and boundaries and cells of convective flows..

    Distribution of flares on the sun-Superactive regions and active zones of 1980-1985
    T Bai – The Astrophysical Journal, 1987 – adsabs.harvard.edu

    Distribution of flares on the sun during 1955-1985-‘Hot spots'(active zones) lasting for 30 years
    T Bai – The Astrophysical Journal, 1988 – adsabs.harvard.edu

    The north-south distribution of major solar flare events, sunspot magnetic classes and sunspot areas (1955–1974)
    JR Roy – Solar Physics, 1977 – Springer

    so if we are looking for a consistency in these convective flows for years…

  40. Carla says:
    December 8, 2013 at 9:32 am
    Some might use slightly different terminology but this seems relative to sectors and boundaries and cells of convective flows..
    Yes, those ‘active longitudes’ have been recognized for more than a hundred years. Maunder was the first to draw attention to them.

  41. Yes, thanks Dr. S., this does answer some of my questions and creates more. lol But, is there more of an inward component than an outward. That the inward component of the structures is more dominant?

    Long Term Evolution of the Solar Sector Structure

    http://www.leif.org/research/Long-term%20Evolution%20of%20Solar%20Sector%20Structure.pdf

    Svalgaard and Wilcox 1974
    … During most of the cycle a four-sector structure with asynodic recurrence period near 27 days is apparent. On the other hand, near sunspot maximum a superposed structure having polarity into the Sun and width in longitude of about 100 deg. and a recurrence period between 28 and 29 days can be observed. This 28 1/2 day feature co-exists with the underlying basic four sectors for several years. It may at these times be more difficult to discern the four-sector structure clearly, and the observed solar -structure has in a first approximation only two sectors per rotation. But when the 28 1/2 day structure weakens sometime after sunspot maximum, the four-sector pattern becomes very prominent again as the cycle progresses towards sunspot minimum. …

    So more wavy current sheet during minimum and/or reduced (low activity) solar cycle?

  42. Now this is pretty significant and interesting..for our understanding of these convective cells too..

    Long Term Evolution of the Solar Sector Structure

    http://www.leif.org/research/Long-term%20Evolution%20of%20Solar%20Sector%20Structure.pdf

    Svalgaard and Wilcox 1974
    … In this paper we present evidence for the notion that the basic four-sector structure is a manifestation of a intrinsic three-dimensional structure in the global solar magnetic and/or velocity fields.

    The structure is a very long-lived and appears to have existed throughout the last five sunspot cycles, and by implication probably much longer than that.

    It will be shown that the sector boundaries drift slowly in longitude. These slow systematic longitude drifts are related to the sunspot cycle in the sense that from sunspot minimum until the polar fields reverse shortly after the maximum, the sectors drift westwards. After the polar field reversal, the sectors drift eastward until the next minimum, when they again resume a westward drift. The drifts are slow, of the of 20 deg. of longitude per year…

    Might that structure be a birth mark of sorts?
    The drift reminds me, Earth’s wavy magnetic equator has a drift. As well as other drifts within the region..

  43. Figure 5 expands brain and head explodes..wowee
    “the existence of a negative polarity feature with a 28 1/2 day recurrence period” and kaboom
    But the galactic mother brain says, your looking at Figure 5 from the wrong Earthly angle again.

    Long Term Evolution of the Solar Sector Structure

    http://www.leif.org/research/Long-term%20Evolution%20of%20Solar%20Sector%20Structure.pdf

    Svalgaard and Wilcox 1974

    …Figure 5 shows in a compact representation the three principal features that emerge from the present analysis: (i) a persistent four-sector structure which may be followed from one cycle to the next and presumabley represents a very long-lived structure in solar magnetic fields, (ii) systematic changes of the recurrence period – or rotation period – of this four-sector structure: faster rotation in the first half of a sunspot cycle, slower rotation in the last half, and
    (iii) the existence of a negative polarity feature with a 28 1/2 day recurrence period; the 28 1/2 day structure seems to be most prominent near sunspot maximum, although at times can be quite distinct even near minimum such as in 1943 and in 1972-73…

    Good stuff, now maybe a lookee see at “FLARING SOLAR HALE SECTOR BOUNDARIES.”

  44. This all does sorta remind me of the “Arctic Oscillation.” (Polar Oscillation)
    Sometimes, in Negative phase (high pressure) and more wavy the jet stream.
    Then at other times Positive phase (low pressure) more flat or smooth the jet stream.

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