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.
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
1NASA Marshall Space Flight Center, Huntsville, AL 35812, USA.
2Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235, USA.
3Department of Space Science, University of Alabama in Huntsville, Huntsville, AL 35899, USA.
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.
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“Giant convection cells found on the sun”
So THAT’S where the heat went missing……………………
Crikey…..
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’?
DD…
It would explain the pause though wouldn’t it?
Dr Evil
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.
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.
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.
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.
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.
Oh man, how did we screw THAT up? CO2 again?
“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.
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…
Bush’s fault.
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.
How big is exactly the nuclear reactor core of the sun ?
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
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
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…
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
Nature’s take: http://www.nature.com/news/probe-spots-enormous-convection-currents-on-the-sun-1.14312
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…)?
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.
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..
Carla says:
December 5, 2013 at 6:55 pm
Figured you have probably been watching the sector structures for years..
46 years to be precise.
Wikipedia has an article on the Solar Core. Core is surrounded by radiative then convention zones. Number for today is 380 yottawatts. http://en.wikipedia.org/wiki/Solar_core
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.