What causes Cosmic Mass Ejections (CMEs)?

Discussion in 'Physics & Math' started by Confused2, Aug 3, 2016.

  1. Confused2 Registered Senior Member

    Messages:
    609
    If Magnetic Lines then what are they?
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. sculptor Valued Senior Member

    Messages:
    8,466
    To start you on your way:
    CME = A coronal mass ejection
    not cosmic
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Confused2 Registered Senior Member

    Messages:
    609
    Thanks for pointing that out. It would be appreciated if a moderator would make the correction.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. paddoboy Valued Senior Member

    Messages:
    27,543
    One of the more puzzling aspects of our Sun, is why the corona [or Sun's atmosphere] is hotter than the Photosphere [or surface of the Sun]
    The best theory is that magnetic fields originating from deep inside the Sun, is carrying this energy and plasma to the corona.......
    http://www.zmescience.com/research/why-sun-corona-is-hotter-than-surface-03421432/
    extract:
    A study published in 2012 in Nature Communicationsby researchers at Northumbria University found a possible mechanism that causes some stars to have a corona that is almost 200 times hotter than their photosphere (the star’s surface). The researchers used cutting-edge solar-imaging technology to observe the Sun’s chromosphere – a distinct region of the sun’s atmosphere sandwiched between the photosphere and the outer corona. Here, the researchers examined magnetohydrodynamic (MHD) waves and measured their speed and power with unprecedented detail using the dedicated solar-imaging telescope known as Rapid Oscillations in the Solar Atmosphere, or ROSA.
    """"""""""""""""""""""""""""""""""""""""""""""""""""
    Is this what your question is concerning?
     
    sculptor likes this.
  8. Confused2 Registered Senior Member

    Messages:
    609
    Thanks Paddoboy.
    Thanks Paddoboy. I think this is a point of general interest. What I'm looking for is a mechanism that can fire off (for example) a billion tons of matter at (for example) 500km/s (figures from wikipedia https://en.wikipedia.org/wiki/Coronal_mass_ejection ). I'm hoping for an explanation either dumbed down to the point that it makes sense within the realms of high school physics or (somehow) improving my (everyone's) physics to the point that the explanation makes sense. One might look at a railgun (https://en.wikipedia.org/wiki/Railgun ) as a starting point only to say 'we see no such mechanism in the Sun'.
     
  9. paddoboy Valued Senior Member

    Messages:
    27,543
    Sometimes getting "dumbed down" explanations of not well known or explained cosmic events such as CME's is difficult.
    As a lay person, I try and stick with reputable explanations and papers that certainly are not "dumbed down" but in such cases I will read again and again, sometimes half a dozen times to try and gauge what is being theorised.
    I did find a couple of papers that you possibly may be able to get the gist of to answer your query as best as is possible at this stage.......
    http://arxiv.org/pdf/1511.06110v1.pdf
    [The above had me somewhat confused on the first reading, until I gauged that there are similarities as well as differences between CME's and Solar Coronal jets. [My confusion was that I saw them as the same thing]
    That is explained somewhat in the following......
    https://arxiv.org/abs/1607.02108
    "Coronal jets represent important manifestations of ubiquitous solar transients, which may be the source of significant mass and energy input to the upper solar atmosphere and the solar wind. While the energy involved in a jet-like event is smaller than that of "nominal" solar flares and coronal mass ejections (CMEs), jets share many common properties with these phenomena, in particular, the explosive magnetically driven dynamics. Studies of jets could, therefore, provide critical insight for understanding the larger, more complex drivers of the solar activity"


    More stuff......
    http://www.aanda.org/articles/aa/pdf/2010/08/aa13167-09.pdf
    [Investigating the driving mechanisms of coronal mass ejections]
     
  10. Confused2 Registered Senior Member

    Messages:
    609
    Thanks Paddoboy - excellent stuff.
    Two (possibly) unexpected (geometric) arc properties of electric arcs:-

     
    Last edited: Aug 4, 2016
  11. Confused2 Registered Senior Member

    Messages:
    609
    With hindsight the OP would seem to be overly ambitious for a high school physics non-graduate. An explanation for the Jacob's Ladder effect might be a more sensible starting point.
     
  12. origin Heading towards oblivion Valued Senior Member

    Messages:
    11,888
    A nice concise explanation from the website: http://wonders.physics.wisc.edu/jacob-s-ladder.htm

    Quick Physics: The transformer at the bottom creates a potential difference between the wires. The electrons repel each other, so they jump from one wire to try and get as far apart as possible. The spark heats up the surrounding air and hot air rises, so the spark rises with it. When the spark gets to the top of the wires, it dies and a new one starts at the bottom.
     
    Confused2 likes this.
  13. Confused2 Registered Senior Member

    Messages:
    609
    It would be interesting to try the ladder upside down. Regardless it may be that the arc (geometry) arcs seen on the surface of the Sun are no more complex than hot air (hydrogen) rises? The coronal mass discharges are at (order of) km/s. The temperature in the photosphere is billed as (order of) millions of degrees. Too busy right now but these guys https://en.wikipedia.org/wiki/Maxwell–Boltzmann_distribution might be worth consulting.
     
  14. origin Heading towards oblivion Valued Senior Member

    Messages:
    11,888
    I do not think so. The CMEs are associated with sunspots which in turn are areas where concentrated magnetic lined of force pierce the surface of the sun. Keep in mind that the sun is made up of charged plasma and those moving charges make very strong magnetic fields. It seems to me that every 11 years when the overall magnetic field of the sun flips the lower magnetic field can allow fluidic currents of plasma to form due to the diffential temperatures of the plasma. That will result in local strong magnetic fields that have an associated north magnetic sunspot and a south magnetic sunspot. One of the threories, that I like, is that there is a reconnecting of magnetic lines that cross leading to a huge release of energy and plasma from the surface of the sun.
     
  15. el es Registered Senior Member

    Messages:
    322
  16. Confused2 Registered Senior Member

    Messages:
    609
    I would (naively) expect the plasma to be roughly electrically neutral. Do we have a mechanism to make a charged plasma?
     
  17. expletives deleted Registered Senior Member

    Messages:
    410
    Confused2:

    The internal flows are complex, and charge separation occurs naturally due to gravity related vertical flows ('convection cell' currents) as well as electromagnetism (dipolar and multipolar magnetic field and plasma structures forming and evolving and collapsing).

    The convection currents sort the 'cooler' plasma from the hotter plasma, into sheaths and bubbles of open or closed plasma flows having their own localized electromagnetic dynamics; which then further tend to magnetically 'sort' lighter less massive charged particles in the plasma (speedy electrons) from the comparatively heavier more massive ions (less speedy protons and other even heavier and more massive ionized nucleons).

    These charge separations and flows form transient and persistent currents of electrons which effectively form negatively charged poles and surfaces when they swirl and flow to create plasmoids and sheaths 'structures' which have negative charge compared to the heavier positively charged protons and other nucleonic ions also entrained but temporarily separated in the swirls and sheaths structures until the structures explode as seen on the sun when the magnetic sorting and flows short-circuit and collapse; some material forming the disordered remnants that fall back onto the sun, some material being dispersed among the other coronal material and flows, and some material sometimes being ejected along an electro-magnetic 'funnel' feature focusing material outwards away from the sun surface (much as polar jets electro-magnetic 'funnels' direct material away from novae and feeding black holes along polar jets having highly ordered directionally; although the randomly distributed and occurring jets of material leaving as coronal mass ejections from all over the sun aren't of the sun's overall dipolar magnetism types, but rather of the localized magnetic dipolar 'sun spot' types coming and going across the sun surface).


    The above is my current understanding of the phenomena you enquired about, Confused2, in the context of the solar dynamics and its electric charge 'sorting' capabilities based on gravitational and magnetic field effects on the plasma. Best.
     
    Last edited: Aug 4, 2016

Share This Page