Powerful Magnetic Waves Help Make Sun's Atmosphere Hotter Than Sun Itself

By Joseph Castro | July 29, 2011 8:34 am

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What’s the News: An international team of researchers, led by the National Center for Atmospheric Research, has learned that large magnetic waves are partly to blame for the Sun’s immensely hot corona. The study, published in the journal Nature, also suggests that the waves could be the driving force behind the solar wind.

What’s the Context:

  • The corona is the outer atmosphere of the Sun, which is only visible by the naked eye during a solar eclipse. It has fascinated solar physicists for decades because it’s over 20 times hotter than the surface of the sun—you’d expect that the further away you get from a heat source, the cooler it gets.
  • One possible explanation for the corona’s extreme temperature has been Alfvén waves, first proposed by Nobel Prize-winner Hannes Alfvén. Alfvén waves are high-speed magnetic oscillations thought to travel along the Sun’s magnetic field lines, transporting large amounts of energy (in the form of heat) from the surface to the corona in the process. In 2007, researchers finally observed these waves, but the waves were too sporadic and weak to explain the corona’s temperature.

How the Heck:

  • Using instruments at NASA’s Solar Dynamics Observatory, scientists examined spicules—short-lived jets of hot, ionized gas—expelled from the Sun. Because these plasma jets also move along the star’s magnetic field lines, the researchers could determine the energy of the Alfvén waves as they bent the spicules.
  • The team used statistical models to interpret data from X-ray and UV snapshots of the jets and waves. They found that Alfvén waves are energetic enough to heat much of the Sun’s corona, as well as drive the acceleration of the solar wind, a stream of electrically charged particles traveling out of the corona at about 1 million miles per hour.

Not So Fast:

  • While the study revealed that Alfvén waves are over 100 times stronger than previously thought, they still didn’t have enough energy to heat the hottest portions of the corona. There may be some other mechanism adding to the corona’s temperature, or more mysteries to unravel about the Alfvén waves.
  • The researchers still don’t know exactly how the magnetic waves are able to transmit all of that energy.

(via Popular Mechanics)

Image courtesy of NASA Goddard Photo and Video / Flickr

  • John Lerch

    Since they corona is hotter than the surface, surely that must mean that the energy is transported from the interior rather than from the surface (as the article says). And if they are not directly from the interior, then some other process must be coupled strongly to the interior.

  • http://www.dogstrainingcollars.com Lori C. Burch

    Does that mean that magnetic waves could add to the heating of the planets? Is anyone looking at past records to see how magnetic waves correspond to average global temps? These answers will be interesting to see.

  • demopublican

    Could be that heat is generated in the Sun’s center, but travels so fast that it isn’t retained in the center.

    Of course, when is gets to the surface, you hav more surface ara, and that its possible magnetic fields and other natural causes causes the heat to collct, i.e. stack up at the surface like a greenhouse effect. Of course, that could be why eruptions occur–heat/energy breaking out of that greenhouse violently.

    As for the US’s heat wave, likely not a cause considering much of the rest of the world is pretty normal… And look at the West Coast–pretty normal weather there.

  • jc

    @3…yeah, that’s right, the rest of the world is pretty normal…no heat waves or floods anywhere in recent memory. Nothing unusual.

  • SirWilhelm

    It’s an elementary law of physics that you can’t have magnetism without electricity. Plasma is ionized gas, made up of charged particles, and charge equals electricty, and electricity creates magnetism. The corona is where most of the Sun’s heat is created, because the Sun is a z-pinch in a Birkeland current. Sunspots are dark, because the interior of the Sun is actually cooler than the surface, impossible if it’s a fusion reactor. These observations are confirming Plasma, or Electric Universe theory, while falsifying Big Bang theory. They are being forced to recognize the work of a plasma physcist, Hannes Alfven, and the role plasma plays in the Universe, including the Sun. The Universe is 99.9% plasma.

  • http://discovermagazine.com Iain

    @ Sir Wilhelm
    You can have magnetism without electricity, or do you somehow have electricity running in circles in permanent magnets?
    Charge does not equal electricity. Although the potential is there.
    Sunspots aren’t dark, they just look that way as they emit fewer photons (equals lower temperature) than the surrounding plasma.
    Fusion is happening at the suns core, approx. 400,000 miles from the corona. It is natural for the temperature to drop as you remove from the source. However as the pressure of the plasma decreases, it absorbs heat, getting hotter as it moves outward. (thermodynamics 101)
    The hot corona is not the proof you wish for.
    The universe is 99.999 % vacuum (maybe more) so Vacuum Energy would far outweigh plasma energy.

  • Doug

    Seems like common sense to me when you add two properties of heat together.

    – Heat rises
    – Heat takes time to transfer across substances

    The corollary to the first is that any cooling that takes place as heat is transferred to the surrounding space will “fall” onto the surface (within the gaseous medium), which would then be cooler than the area that is actively involved in the transfer of heat to the surrounding space.

    The only way I can think of for this not to be the case is if there were no convection currents in the matter streams from the surface, and I just have to believe that is not the case here.

    But then again… I never learned about this kind of thing in school so I just have to rely on my own logic and reasoning here – it could be very faulty indeed.

    As for SirWilhelm’s comments and Iain’s response: I believe he was referring to a difference in electron charge, not electricity per se, and electron charge does “equate” to electrical potential (his wording could have been better). I can’t talk to the rest of it – although it sure seems like a stretch to me to link any of this to big bang theory in any reasonable manner.

  • http://lala chessmaster

    Lain the only other way to magnetism besides electricity is the spin state of electrons, but they cannot produce electricity on the level we are talking about, so it is not really relevant.
    Sir Wilhelm you are correct the electric model works very well with observation ,o both on a micro and a macro-galactic scale. The z-pinch theory can also account for the neutrinos being detected contrary to po9lular belief it can account for all three species of neutrinos as well . There i no difference between nuclear reactions in a reactor or one caused by z-pinch pressure when it comes to neutrinos released
    So there could be actually nuclear reactions taking place in the corona itself !! This makes sense when observation shows that is the hottest region of the sun. There is alot of dubious language involved in the standards models invented process of magnetodynamics that is based on absolutely no observation and is kinda AdhoC in purpose. This is due to the fact that all observations have betrayed the standard models predictions.
    But hey if people found out he truth they could get free energy, where the hell do you think lightening comes from??? Do YOU REALLY BELIEVE IT IS GENERATED BY A CLOUD ???Even though red sprites extend miles into the upper atmosphere and even lower space. Lightening is obviously power by Birkland or cosmic rays of some sort. There is no other way a reaction could extend into space unless the source of power was coming from there. Not to mention a cloud cannot even come close to generating that sort of energy. But hey if we found out the truth all that grant money would disappear and dry up .

  • katesisco

    Really nice: Voyager finds magnetic bubbles at edge. This area is compressed. You may see it as a BC.
    Above Ian: @ Sir Wilhelm
    You can have magnetism without electricity, or do you somehow have electricity running in circles in permanent magnets?
    Charge does not equal electricity. Although the potential is there.
    I love this permanent magnet concept. Did you know the ancient Egyptian of Crocopolis is the site of the Egyptian Labrynth http://www.catchpenny.org/labyrin.html
    is actually a permanent magnet.
    As for the lack of the energy to support the supposed reaction, it seems that so many times the energy regquired comes up short but then there is the sudden input of magnetism.
    2012 Kosovichev and Zharkova theory of sun flares gains new traction.


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