A new method for predicting speed and motion of solar flares

A Montana State University physicist who has developed a new model that predicts the speed of solar plasma during solar flares, likening it to the path traveled by a thrown baseball, will present his findings at the Solar Physics Division of the American Astronomical Society conference being held this week in Boulder, Colorado.

Sean Brannon, a postdoctoral researcher in the MSU Department of Physics within the College of Letters and Science, developed the model that might help to define how solar flares evolve and provide better ways to predict them. His work could have applications on how to protect power grids and communication technology and aeronautics from the energy released by the flares.

Brannon used data from the NASA Interface Region Imaging Spectrograph satellite, also known as IRIS, which monitors a specific layer of the sun known as the transition region. The transition region is thin, but complex, and separates the sun’s outermost layer, the corona, from an inner layer, the chromosphere. The corona, the chromosphere and the transition region are of great interest and mystery to scientists.

Temperatures in the corona can reach several million degrees Kelvin, far hotter — often by more than a factor of 100 — than any other layer of the sun’s atmosphere. A solar flare arcing through the corona can be more than 10 million degrees Kelvin. This is puzzling and seems counterintuitive since the corona is the furthest layer from the sun and, therefore, should arguably be the coolest.

IRIS spectrograms are made by a process similar to what happens when you shine light through a prism, breaking it into different colors. Each color is formed by a different kind of atom in the solar atmosphere and we can extract all kinds of interesting information about what the plasma is doing based on that spectrum. For example, if the light is more red or blue than we’d expect, then we know that the plasma is moving either away from or toward us,” Brannon said.

Brannon used IRIS’s data to look at the sun’s solar flare process. During a solar flare, plasma from the sun can heat up to millions of degrees Kelvin and evaporate into the corona. There it fills or is funneled into powerful magnetic fields that give it an arcing, loop-like shape, Brannon said.

“We then expect that this hot plasma will cool off over the next several minutes to hours. As it cools, models predict that it should start to drain back out of the loops, resulting in spectral signatures that should be detectable,” Brannon said.

“Up until now, however, there haven’t been any published papers analyzing an observation of the entire filling, cooling, and draining process, nor have there been any papers that attempt to model a spectral observation as a signature of the draining,” Brannon said. “The cooling and draining is important to look at, since we’d like to be sure that the plasma we’re measuring is evaporated plasma draining back, and not some other source of plasma.”

Brannon devised a simple model to describe the speed at which a blob of plasma falls from the top of an oval-shaped flare loop and how it would appear on an IRIS spectrograph. His results indicate that plasma is draining from the loops at free-fall speeds – similar to the path a baseball follows when thrown. Additionally, the location and timing of the draining plasma matches that which was observed evaporating.

The prediction of large solar flares is important because they can emit vast amounts of energy that can disrupt power grids, satellites, communication technology and aeronautics. For example, in March 1989, a powerful solar flare left millions of Canadians without electricity for about 12 hours, according to NASA.

“The sun really dominates Earth’s environment, climate and space in which Earth lives,” Brannon said. “What the sun does can have very profound impacts on life here on Earth. So, understanding the sun’s processes can help us determine how to protect technology and people.”

MSU Physics Professor Dana Longcope was Brannon’s academic adviser and is national chairman for the Solar Physics Division. Longcope said that while solar flares are unpredictable making it difficult to find one to observe, Brannon was able to identify a specific IRIS observation, enabling him to make his analysis.

“He came up with a very different interpretation of what happens during a solar flare,” Longcope said. “It is one of the most compelling quantitative observations I’ve seen as to what we’d expect to see during a solar flare. It’s a credit to a scientist when they look at the data and they aren’t blinded by what they expect to see, but rather keep an open mind and observe what is actually happening.”

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57 thoughts on “A new method for predicting speed and motion of solar flares

  1. …”“The sun really dominates Earth’s environment, climate and space in which Earth lives,” Brannon said. “What the sun does can have very profound impacts on life here on Earth. So, understanding the sun’s processes can help us determine how to protect technology and people.”….
    Oops, there goes his chance at another grant !!

    • Who is writing the above story ??
      My flesh creeps when I see the words “degrees kelvin”.
      You would think that solar physics is close to reality, in the general scheme of things, so I would expect more rigorous use of SI units from solar physicists.
      A ” kelvin ” is an absolute Temperature, starting at absolute zero. It increments in steps that are identical in magnitude to Celsius degrees. The Celsius scale is a Centigrade scale that divides the scale range into 100 equal intervals.
      G
      All same, it is interesting to hear of new solar stuff.
      If the solar corona is millions of kelvin, how could “heat” (noun) from a nearly frozen source at a piddly 6,000 kelvin ever get past the corona.
      Maybe it has something to do with photons not understanding what Temperature is.
      Beats the heck out of me.

      • Hi Big G
        number of hypothesis,
        old
        a) magnetic reconnection
        more recent
        b) Magneto-acoustic waves but they are not particularly energetic
        c) Alfvén waves heating (energy transmission)

      • Don’t forget about Corotating Interaction Regions (CIR’s) that form from the fast and slow solar wind interactions along the edges of the helio-current sheet. These too can accelerate particle flux back to the solar corona and produce heating. These are occurring all the time between ?? solar radii and 1AU.

      • Some interesting times ahead indeed if any of these scenarios play out during this period of increasingly lower solar activity and magnetic field strength. Wild if there were no solar reversal for cycle of just half a reversal or something.
        If the article is in my collection it means it was open access. (freebie) Google is our friend. lol
        INFERRING THE STRUCTURE OF THE SOLAR CORONA AND INNER HELIOSPHERE DURING THE
        MAUNDER MINIMUM USING GLOBAL THERMODYNAMIC MAGNETOHYDRODYNAMIC SIMULATIONS
        Pete Riley1, Roberto Lionello1, Jon A. Linker1, Ed Cliver2, Andre Balogh3, Jürg Beer4, Paul Charbonneau5,
        Nancy Crooker6, Marc DeRosa7, Mike Lockwood8, Matt Owens8, Ken McCracken9, Ilya Usoskin10, and S. Koutchmy11
        published 2015 March 30
        2.4. Eclipse Observations
        pg. 5
        In summary then, we conclude that: (1) the corona during
        the Maunder Minimum was likely featureless, at least to the
        extent that it was not commented on; (2) the coronal light that
        was present was “reddish” and (3) coronal features likely
        returned sometime between 1708 and 1766.

  2. ” It’s a credit to a scientist when they look at the data and they aren’t blinded by what they expect to see, but rather keep an open mind and observe what is actually happening.”
    In the good ole days, before “Global Warming”, most scientist behaved this way…What a brilliant Idea to bring back..

    • No.. it will never come back. The scientific integrity can’t co-exist with gov funding that is very competitive. Whole number of formerly known as “exact” sciences are now just a playground for shysters.

  3. “The prediction of large solar flares is important because they can emit vast amounts of energy…”
    So… the sun can make an impact on the earth? whoda thunk?
    We’ll likely hear… that this all “been there done that, nothing new”. But I think it is fantastic and truly enjoy all articles related to the solar influence on the earth.

      • Depending on your use of the ambiguous word “vast” used in the original posting…Vast=empty OR Vast =immense
        So, somewhere between empty and immense.. I guess.

      • ahem…
        1) I said “Depending on your use of the ambiguous word “vast””., not the original post so you ought to be careful tediously mis-correcting people while not reading what was written in the first place.
        and 2) 1565 AD from the Latin vastus, empty and 3) we were engaged in humor so…What is your real name?

  4. Solar flares and coronal mass ejections -CMEs cause geomagnetic storms which can cause problems to electric transmission lines, satellites, radio communications, electronic devices etc.
    A major geomagnetic storm stated yesterday afternoon and is still under way.
    See bottom panel in this illustration from the British geological survey
    http://www.geomag.bgs.ac.uk/images/aphisto.png

  5. well at least a stream of high energy plasma that has emanated from a coronal hole that faced Earth a couple of days ago.

  6. “A solar flare arcing through the corona can be more than 10 million degrees Kelvin. This is puzzling and seems counterintuitive since the corona is the furthest layer from the sun and, therefore, should arguably be the coolest.”
    Consider conservation of energy. The solar atmosphere thins massively at higher altitude. Hence, conservation of energy requires that each plasma particle per unit volume carry more energy (mostly or entirely in the form of kinetic energy).
    The same thing happens in the atmosphere on Earth, except in this case we are dealing with molecules instead of plasma. Have you ever lived in a high desert? Ever wonder why the winds are so strong? Even all through the night?

    • NASA isn’t sure what drives the corona temperature but theories include magneto-acoustic waves, Alfven waves (a form of MHD waves), magnetohydrodynamic (MHD) waves [ I think these first 3 are just different ways waves move through the Sun’s magnetic field and impart energy to the plasma in the corona], micro-flare reconnection, and/or plasma jets. Basically, no one really knows at this time. Competing theories exist but no consensus has come together (as of 2014).

      • A consensus is useless in comparison to reproducible empirical results. (Just sayin’)

      • 3 scientists are sitting in a room. They put forward 3 different theories as to what heats the corona. Clearly none of them know the correct answer. Two of them change their pet theory to match the third. Clearly there is a consensus and all can agree they have solved the mystery of what causes coronal heating.
        If you field of study is small enough, you don’t need to do any research. Co-ordinated navel gazing will solve all the outstanding problems left to be answered? Could this be what happened in Climate Science? Did Hansen and Gore agree on all the wrong answers before anyone thought to search for the right ones?

      • Dr. Robitaille has a fair bit to say on what drives the heat of the corona. His work is worth looking up.

      • It was not my intention to get distracted by a discussion of consensus. In the context of my comment, the lack of consensus was meant to say that there were conflicting theories that each have some empirical evidence (i.e. measured solar parameters or laboratory studies) but that none of those theories have been accepted as proven by the majority of solar scientist because they all leave some aspects of the problem unexplained or they don’t fit all observed conditions. Sorry for the confusion on the word “consensus”.

    • So Dan, If I gather your point, to be that hot (high Temperature) all that is required is that the mean energy per particle has to be kT (or izzat kT/2) per degree of freedom, and if the plasma is mostly protons in an electron cloud, then rotational moments of inertia are not that big so mostly it has to be 3kT (or 3kT/2).
      But what is it that causes these protons basically to accelerate to such velocities ??
      Dr. S is always reminding us that the plasma is not really charged, so there are plenty of electrons, but does their KE have to match the protons on average.
      I have a very vague recollection of somebody saying (Maybe Dr. S) that it is nothing more than gravity letting go of the protons, which then mutually repel, and so accelerate each other. But then that could be a fanciful creation of my growing forgetivity ??
      G

      • Those particles that “escape” to higher altitudes are those that have acquired the energy to do so. Are there other mechanisms at play? Possibly. And if so, that would be a factor, but only a factor.
        My real interest is in the parallel to high wind velocities in high desert terrains. I was simply trying to draw a parallel to offer a different way of thinking about this. Regarding degrees of freedom for a plasma: yes, the energies other than Kinetic are relatively small. For air molecules, other degrees of freedom are more important. But the result is the same. Heat energy drawn by the air from rocks after sunset in a high desert (where the air is thinner than at lower altitudes) will be absorbed by a fewer number of molecules. Hence, regardless of the number of degrees of freedom–the same as at lower altitudes–these molecules appear to have greater total–and hence, greater kinetic–energy. A better question would be “how is this kinetic energy organized into bulk directional winds?” This may be nothing more than local or regional terrain. I was hoping for comments along these lines as i would like to hear others’ thoughts on this weather phenomenon.

      • There is another unknown here. As solar wind particles leave the photosphere (from the distance of 1-2 solar radia) they accelerate to a degree that it can not be accounted for by any of the known forces or processes.

      • Vuk: it is not what you know that gets you in trouble, but what you know that ain’t so. The solar wind expands because it is hot and is a good conductor of heat. It accelerates by the same mechanism that is at work in a de Laval Nozzle used in a rocket engine https://en.wikipedia.org/wiki/De_Laval_nozzle .
        The flaring out of the chamber in the solar wind is the decrease of gravity with distance, so in a sense gravity is the accelerating agent.

      • Hi Doc
        We have discussed that one couple of times before, but I never found a paper that actually considers the effect on the solar wind, with calculations applied to solar wind properties, perhaps a numerical model? Do you know of one?

      • I guess I misremembered that Doc. S had told us that gravity bit before, so it was not mutual proton repulsion that I guessed at.
        I’m still puzzled though, since I thought gravity sucked. So the notion that a fall off of gravity “suction” with radial distance (that I get) actually results in an acceleration, is still puzzling me. But I guess it will hit me with one of those aha moments. It also begs the question as to how far out does the Temperature increase extend, and presumably gravity stops accelerating the particles.
        G

        • The simplest way to see this, is to consider that gravity is holding the particles back. If you slowly decrease gravity [with altitude] that holding back is diminished and the kinetic energy the particles have can now carry them faster, i.e. accelerating it.

  7. I was wondering if anybody else noticed that they didn’t mention CMEs. I guess they are talking about flares and assuming that they are the ones strong enough to eject plasma beyond the corona.

  8. Temperatures in the corona can reach several million degrees Kelvin, far hotter — often by more than a factor of 100 — than any other layer of the sun’s atmosphere.
    =======================
    I’m surprised there is any confusion over this. A cold atmosphere on earth has no problem warming the much warmer surface, so why should there be any confusion over the sun’s colder surface warming a much warmer atmosphere? The answer is clear. It is GHG what done it.

  9. …likening it to the path traveled by a thrown baseball…

    Assuming the pitcher is on a rotating mound and there’s no terrestrial gravity…
    Seems to me to be a gross oversimplification.

  10. “Predicting speed and motion of solar flares”
    Since we do not have any spots and the flares seem to originate from the spots, don’t think the study is looking for grant money at this time.
    Now the “holes” are a different thing. They already have a model that determines when the hole’s emissions comes into geo effective effective position and how long it gets to us. They are doing predictions that takes days to weeks to get here. And yes, it causes the northern lights to light up.
    But now the CMEs, or the ejection of protons when we have a flare. Is it not funny how most of the flares appear to the east and west just as the sun hides them from view. As if the top of the magnetic field that surrounds the top of the spot is reflecting the plasma and directing it toward earth, like a radar antenna that directs radio waves in a focused beam toward its targets.
    I am interested in knowing how long it takes the events (whichevers) to travel and affect the earth’s atmosphere. You might say I am looking for a confirmation. Before the spots dissappeared, I was able to see a small deviation of the barometric pressure. Using GOES data and the deviation, was able to clock them at between 2 and 3 hours. Unfortunately, can’t do that anymore. But I have saved alot of the records to do a more detailed study in the future.

    • confusing post.
      the charged particles from an X class eruption can get 1AU in about 24 hrs. A Carrington X40+ event the first particles, maybe 16 hrs. Avg CME event particles take 48 to 96 hrs to reach 1AU.

      • Joel, IIUC, multiple CMEs along the same spiraling path will “clear the path” for those behind and can result in the later released plasma to catch up to and intensify the lead clouds, making a more potent shock to planetary magnetics.

      • Thanks, Doc: I conflate scientific terms a lot if I’m not careful. (Probably from watching the “Bowery Boys” when I was young). 😉

    • Lee wrote: “Since we do not have any spots and the flares seem to originate from the spots”
      Ah, but a Hyder flare is caused by the collapse of a magnetic filament structure, sometimes resulting in a very large CME. I’ve read speculation of that being what caused the Carrington event, can that be corroborated, anyone?
      I’m curious about the magnetic structures and their relationship to coronal holes and emerging flux in active regions.
      Are they all different manifestations of the same mechanism?

  11. the difficulty I see in this model is that it (the plasma) is not a baseball. Plasma is by definition charged. Thus it is subject to E and B field effects as it falls under g. Which of course is why the corona is 1E+06 degrees while the photosphere is ~6E+03 degrees. Maxwell’s equations are fundamental in that physical system, as well as Newton’s.

  12. “Temperatures in the corona can reach several million degrees Kelvin, far hotter — often by more than a factor of 100 — than any other layer of the sun’s atmosphere. A solar flare arcing through the corona can be more than 10 million degrees Kelvin. This is puzzling and seems counterintuitive since the corona is the furthest layer from the sun and, therefore, should arguably be the coolest.”
    The explanation for this is that there are processes occurring in the corona that are actively very exothermic, generating a great amount of heat. We do not know what these processes are at the present, but we do know that they must be occurring at the lowest layer of the corona, as the heat that they produce diffuses outward (Newton’s Law of Cooling applies).
    My physical intuition is that the processes involve inelastic collisions at the boundary layer and much higher densities than are to be found in the corona itself.

    • I can’t help myself as an old power plant operator, I keep thinking that the surface of the burner is always cooler than the flame, especially the tongue. Are stars just spherical burners on a different scale?

  13. A recap of the the IRIS ( Interface Region Imaging Spectrograph) satellite mission, launched 2013.
    What we have learned so far about heating the solar corona..
    NASA’s IRIS Helps Explain Mysterious Heating of the Solar Atmosphere
    NASA’s newest sun-watcher, the Interface Region Imaging Spectrograph, launched in 2013 with a specific goal: track how energy and heat coursed through a little understood region of the sun called the interface region. Sandwiched between the solar surface and its outer atmosphere, the corona, the interface region is where the cooler temperatures of the sun’s surface transition to the hotter temperatures above. Moreover, all the energy to power the sun’s output — including eruptions such as solar flares and the sun’s constant outflow of particles called the solar wind — must make its way through this region.
    …By looking at various regions of the interface region in unprecedented resolution, the papers offer clues to what heats the corona to unexplained temperatures of millions of degrees, far hotter than the surface of the sun itself, as well as what causes great writhing movement and accelerated particles throughout the solar atmosphere.
    Solar Heat Bombs
    One of the biggest surprises comes in the form of heat pockets of 200,000 F, low in the solar atmosphere – far lower down than where such high temperatures were expected. In a paper led by Hardi Peter of the Max Planck Institute for Solar System Research in Gottingen, Germany, the pockets were named bombs because of how much energy they release in such a short time.
    Resolving Unresolved Structure
    …Able to see hundreds of times more detail than Skylab, IRIS has resolved numerous, small, low lying loops of material in the transition region, as described in a paper led by Viggo Hansteen, a solar scientist at the University of Oslo in Norway. These move quickly and last for only minutes at a time. At just a couple thousand miles high, the loops could not be seen with any previous instrument. Identifying such loops offers new insight into how the transition region emits the light and energy that we see: These loops show us a dynamic region where much heating occurs and is quickly released.
    Mini-Tornadoes
    ..A third paper uses IRIS to determine speeds of structures in the other part of the interface region just above the sun’s surface, called the chromosphere. The solar features seem to be twisting – one side of the loop appears to be moving away from the viewer, the other side is moving toward it.
    “We conclude that the gas in the chromosphere is often twisting like a tornado twirling around a central magnetic tube,” said De Pontieu, who is also the first author on this paper. “These twisting motions are often associated with heating to hundreds of thousands of degrees.”
    While fairly small by solar standards, these mini-tornadoes twist at up to 12 miles per second, and are scattered throughout the chromosphere. The tornadoes are signatures of a magnetic feature called Alfven waves, which are known to be able to carry energy and heat throughout the solar material.
    High Speed Jets
    The IRIS observations show such intermittent jets coming out of areas of weaker magnetic fields and less dense material in the solar atmosphere, called coronal holes, which are typically thought to be a source of the solar wind. Scientists’ next steps are to determine whether the jets are indeed the origins of the solar wind – in contrast to previous predictions that the solar wind traveled through the interface region at just a couple miles per second – or at least how it relates to the solar wind.
    Additionally, the jets show temperatures of 200,000 F and can be many times taller than the relatively thin transition region itself, which is about 300 miles high. Hui states that the jets appear to be one of the most important basic structures in the transition region – knowing more about them could help explain why the amount of energy emitted from the transition region is brighter than models would predict.
    Accelerated Electrons in Nanoflares
    The final paper spotted the effects of ubiquitous nanoflares throughout the corona. Large solar flares are initiated by a mechanism called magnetic reconnection, during which magnetic field lines cross and explosively realign, often sending particles zooming off at near-light speeds. Nanoflares are smaller versions of these that have long been hypothesized to drive coronal heating as they might release enough energy sufficient to heat the entire corona. In this paper, Paola Testa, also at the Harvard-Smithsonian Center for Astrophysics, used IRIS’ ability to measure velocity to determine how the material at the footpoints of magnetic loops react to the accelerated particles that slam down into the interface region.
    “Nanoflares have long been associated with coronal heating,” said Title. “With this research we can show the properties of these high energy electrons and how they affect the interface region – the area where the bulk of solar atmospheric heating is known to occur.”
    This research has applications beyond just understanding the sun: These high-speed electrons also occur in other stars. Understanding what accelerates them on the sun can translate to better understanding of a host of astrophysical events.
    http://www.nasa.gov/content/goddard/iris-helps-explain-heating-of-solar-atmosphere

    • Here’s one a while back on March 17th that was kind of revealing from its angle of view. We won’t be able to post recent flares very often for the next 5 years, but that doesn’t rule out sporadic activity.

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