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On the Origin of Solar and Stellar Magnetic Fields

  1. Jul 27, 2012 #1
    On the Origin of Solar and Stellar Magnetic Fields

    There is recent evidence that the solar magnetic cycle has been interrupted.

    This is a link to Livingston and Penn’s paper that notes the magnetic field strength of newly formed sunspots is decreasingly linearly. Specifically, why the magnetic field strength of newly formed sunspots is decreasing is not known. There is in the paleoclimatic record evidence of unexplained cyclic abrupt climate changes (Bond events and Heinrich events) that correlate with abrupt cosmogenic isotope changes. The cosmogenic isotope changes are known to be caused by solar magnetic cycle changes and by geomagnetic field changes. It is time for the next 1470 year Bond climate change event and the next 8,000 to 10,000 year Heinrich event (It appears the Heinrich event is a very, very, strong Bond event). Assuming the sun was the cause of the past Bond and Heinrich events, the solar magnetic cycle from time to time is interrupted. Based on an assume mechanism that explains what is observed in the paleo record, the restart of the solar magnetic cycle is what causes the Bond and Heinrich events.

    I am not interesting in discussing the fundamental mechanisms (solar, geomagnetic, and atmospheric) how a solar magnetic cycle interruption could physically cause what is observed unless there is definitive evidence that the solar magnetic cycle has been interrupted in an anomalous manner as opposed to a normal cyclic slowdown of the solar magnetic cycle. There may be a number of months or years before there is evidence to resolve this question.

    I will however start a separate thread to discuss structured astronomical anomalies which appear to point to a possible theoretical explanation. (i.e. I have been specifically looking for astronomical evidence to construct and support a strawman mechanism. What I found is interesting regardless of whether it does or does not support a new mechanism for the generation of astronomical magnetic fields.)


    http://arxiv.org/abs/1009.0784

    There is a suite of recent astronomical and solar observational evidence that supports the assertion that the assumed fundamental mechanisms by which magnetic fields are created in stellar and very large astronomical bodies is incorrect. The seismological evidence that the solar convection is 20 to 100 times less than theoretically assumed which makes the assumed mechanism to generate the solar magnetic field not possible is only one of many.


    http://www.nyu.edu/about/news-publi...-create-mri-of-the-suns-interior-motions.html


    http://arxiv.org/pdf/1206.3173.pdf

     
  2. jcsd
  3. Jul 29, 2012 #2

    Dotini

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    Gold Member

    Some seriously interesting and provocative stuff is being brought up here.

    NASA is thoroughly on record as saying that the solar magnetic field is key to studying and understanding almost all of its Big Questions - coronal heating process, nature of solar flares, origin of sunspot cycle - about these and other continuously varying characteristics of the sun.

    For a relatively new science, helioseismology, to come along and challenge the well-accepted dynamo model of the origin of the solar magnetic field is a big deal to my tiny mind.

    Before the mainstream goes dashing off the reservation into alternative hypotheses, I'd expect a lengthy period of skepticism and confirmation with respect to the findings of helioseismologists. After all, helioseismology, the study of moving lumps and bumps on the sun, is not too far removed from phrenology, the discredited science of studying lumps and bumps on the human head! (Please forgive my corny joke) :)

    Respectfully submitted,
    Steve
     
  4. Jul 29, 2012 #3
    I don't think that any of this challenges the dynamo model. The dynamo model is a very, very basic explanation for how an astrophysical object could generate a magnetic field, but it's a basic framework, and no one knows the exact details.

    We don't know why the sun has an 11 year sunspot cycle.

    There is no "mainstream hypothesis". Just a vague framework without any details.

    Also, as with most press releases, it's really hard to see what the authors are claiming. I very, very seriously doubt that they are arguing that the solar magnetic field can't come from a dynamo effect. More likely they are claiming that a specific version of the dynamo theory is incorrect. I can't tell this from the paper because it doesn't have any information on it.

    They don't mention magnetic fields in the paper. They mention mixing length theory, but mixing length theory is one of those "we know it's wrong, but we don't have the data to do anything better" theories of convection.

    The other thing is that people take heliosesmology very, very seriously since the results are extremely well grounded. One of the big triumphs of helioseismology involved the solar neutrino problem. We see fewer neutrinos then we expect. Either there is something strange about the sun or there is something strange about neutrino. The helioseismology people were able to establish that there wasn't anything weird about the sun (as far as temperature goes) so it turned out that neutrinos were weird.
     
    Last edited: Jul 29, 2012
  5. Jul 31, 2012 #4
    Attached is a link to Livingston and Penn's data updated to July, 2012.

    http://www.leif.org/research/Livingston and Penn.png

    As they note in their paper there are no sunspots with a magnetic field strength less than around 1500 gauss. Specifically what will happen next is not known.

    Will the magnetic field strength of individual sunspots continue to decline or does the mechanism reach a plateau?

    Is it possible to interrupt the solar magnetic cycle? If so, how does the cycle restart?

    It make take a number of months or years to answer these questions. I will update this thread if there is any significant solar change or new papers related to this subject.
     
  6. Aug 4, 2012 #5
    I went to http://arxiv.org/abs/1009.0784 and don't agree with that.

    The period of the solar magnetic cycle has not changed, so as far as I'm concerned the cycle hasn't been interrupted. What they are saying is that the magnetic fields of sunspots are weaker. If the fields get below 1500 gauss then the sunspots will still be there, they just won't be visible. It is not clear what at all this means, and there is no particular reason to worry about it.

    If convective currents are 1/100 of what was thought, then they've got some rethinking to do. It is pretty difficult to figure out what is going on in the interior of the sun. We don't even have all that great of an idea what is going on in the interior of the Earth.


    As to the solar cycle I thought it was reasonably well understood. (I don't feel I have time right now to share my understanding, should I dare call it that.) What is not understood at all are longer cycles of the Sun, like the so-called Little Ice Age. It is a complicated system, that's all I can say.
     
  7. Aug 7, 2012 #6
    In reply to ImaLooser.

     
  8. Aug 9, 2012 #7

    Interesting stuff. that.
     
  9. Oct 4, 2012 #8
    The following is an update of solar magnetic cycle 24.

    Jan Alvestad a long time solar observer is predicting that the solar cycle 24 maximum will be 66.9 and that the solar maximum occurred February, 2012.

    See monthly solar cycle data in this link.

    http://www.solen.info/solar/

    The northern solar magnetic field has changed polarity which indicates that there will be few or no sunspots produced in the solar northern hemisphere based on past observations.
    The southern solar magnetic field has not changed polarity. Some predict that the solar southern hemisphere will change polarity in 2014.


    The following is a graphical comparison of solar cycle 21, 22, 23, and 24.
    http://www.solen.info/solar/cyclcomp.html [Broken]

    The solar wind speed is anomalously low. If I remember correctly there was a theoretical calculation that indicated the minimum possible solar wind speed is 300 km/hr. During the solar cycle 23/24 minimum the average solar wind speed dropped below 300 km/hr.

    It will be interested to see how low the solar wind speed drops to as solar cycle 24 ends.

     
    Last edited by a moderator: May 6, 2017
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