Plasma flow near sun’s surface explains sunspots, other solar phenomena

Posted: September 21, 2019 by oldbrew in Cycles, Electro-magnetism, modelling, research, Solar physics
Tags: ,

Sunspots [image credit: NASA]


Here it’s claimed that the model matches the observations, which is surely a good start in any research. With a deep solar minimum now in progress, theorists should have plenty of new data to work with.

For 400 years people have tracked sunspots, the dark patches that appear for weeks at a time on the sun’s surface, says Phys.org.

They have observed but been unable to explain why the number of spots peaks every 11 years.

A University of Washington study published this month in the journal Physics of Plasmas proposes a model of plasma motion that would explain the 11-year sunspot cycle and several other previously mysterious properties of the sun.

“Our model is completely different from a normal picture of the sun,” said first author Thomas Jarboe, a UW professor of aeronautics and astronautics. “I really think we’re the first people that are telling you the nature and source of solar magnetic phenomena—how the sun works.”

The authors created a model based on their previous work with fusion energy research. The model shows that a thin layer beneath the sun’s surface is key to many of the features we see from Earth, like sunspots, magnetic reversals and solar flow, and is backed up by comparisons with observations of the sun.

“The observational data are key to confirming our picture of how the sun functions,” Jarboe said.

In the new model, a thin layer of magnetic flux and plasma, or free-floating electrons, moves at different speeds on different parts of the sun. The difference in speed between the flows creates twists of magnetism, known as magnetic helicity, that are similar to what happens in some fusion reactor concepts.

Every 11 years, the sun grows this layer until it’s too big to be stable, and then it sloughs off,” Jarboe said. Its departure exposes the lower layer of plasma moving in the opposite direction with a flipped magnetic field.

When the circuits in both hemispheres are moving at the same speed, more sunspots appear. When the circuits are different speeds, there is less sunspot activity. That mismatch, Jarboe says, may have happened during the decades of little sunspot activity known as the “Maunder Minimum.”

“If the two hemispheres rotate at different speeds, then the sunspots near the equator won’t match up, and the whole thing will die,” Jarboe said.

“Scientists had thought that a sunspot was generated down at 30 percent of the depth of the sun, and then came up in a twisted rope of plasma that pops out,” Jarboe said.

Instead, his model shows that the sunspots are in the “supergranules” that form within the thin, subsurface layer of plasma that the study calculates to be roughly 100 to 300 miles (150 to 450 kilometers) thick, or a fraction of the sun’s 430,000-mile radius.

“The sunspot is an amazing thing. There’s nothing there, and then all of a sudden, you see it in a flash,” Jarboe said.

Full report here.

Comments
  1. tallbloke says:

    All getting a bit “electric universe” isn’t it?
    Of course, here at the talkshop, we have the benefit of our friend Rick Salvador’s planetary orbital resonance based model, which replicates 370 years of sunspot observations to better than R^2 = 0.9. So we know this surface phenomenon is connected with planetary motion.

  2. stpaulchuck says:

    tallbloke says:
    September 21, 2019 at 4:16 pm
    —————————–

    do you think the planetary orbital convergences/divergences are affecting the differential rotation? Perhaps due to gravitational drag cycling?

  3. oldbrew says:

    Study Blames Plasma Flow for Spotless Sun (2011)

    “This is the first paper that is able to provide a rationale and reproduce two of the main characteristics of the extended solar minimum,” said NASA solar physicist Madhulika Guhathakurta, who was not involved in the new work. “For something as complicated as the solar dynamo and solar cycle, this relatively simple model has produced remarkable results.”

    https://www.wired.com/2011/03/spotless-sun-model/

  4. GregG says:

    From Rick Salvador’s 2013 paper (with help from R. Tattersall, P. Vaughan, T. Channon and I. Wilson):

    “The unusual orbital rotation of Uranus around its equator, I believe, is a
    possible indication of a magnetic to magnetic field interaction.”

    “…I believe this model captures a fundamental relationship
    between a gravitational disturbance in the Sun’s magnetic
    field through the Tidal Torque process and a magnetic disturbance in the Sun’s magnetic field through the Jovian planets.”

    My thoughts exactly; The planets have both a gravitational and electromagnetic influence on the Sun’s cycles. The question is how much each influences the magnitude and timing of the Sun’s cycles. I believe that more computational analysis will help derive a model that allows for accurate future predictions.

  5. Yes Roger. The cycle of sunspots is roughly 11 years but people seem to forget that the orbit of Jupiter is about 11.8 years the orbit of Saturn is 2.5 longer at 29.5 years, the orbit of Uranus is about 7.1 longer at 84.1 years and Neptune 14 times longer at 165 years. Earth has an orbit of about 1 yr and Venus in the opposite direction of 0.61 years. The intensity of sunspots can be related to the planetary alignment as indicated by your work and the work of others including the indications of Miles Mathis.