Astronomers May Have Cracked the Case of the Quiet, Spotless Sun

By Eliza Strickland | June 19, 2009 3:01 pm

sunspotThe sun has been surprisingly quiet lately, and until now astronomers couldn’t figure out why. An 11-year cycle governs solar flares and sunspots, and researchers knew that we were at the end of a cycle in a “solar minimum” or quiet period–but that somnolence has continued for an extra year beyond the point at which researchers expected sunspot activity to resume. Comments Australian astronomer Phil Wilkinson: “We have had a drought of sunspots…. This is the longest period the sun has been quiet since the start of the Space Age. Seeing the sun doing nothing is really exciting,” he said, adding it made physicists wonder how little they really understood [Sydney Morning Herald].

Now, new observations announced at a meeting of the American Astronomical Society reveal a possible explanation: “sluggish” solar jet streams 4,350 miles below the surface of the sun. Every 11 years, the sun simultaneously generates twin streams of plasma at each of its poles. Unlike the jet streams on Earth, the solar versions are magnetized and travel only toward the equator. This migration takes place very slowly–at about 10 kilometers per hour. For reasons still not understood, when the streams reach 22 degrees of latitude, north and south, they touch off a new solar cycle, and the sunspots reappear [ScienceNOW Daily News].

National Solar Observatory researchers Frank Hill and Rachel Howe monitored the jet stream with ground- and space-based telescopes, using a relatively new science called helioseismology that traces sound waves to reveal conditions in the Sun’s interior [Physics World]. They studied subtle movements in the Sun’s outer layer to trace the movement of the buried jet stream, and determined that the stream had taken an extra year to migrate down towards the equator–although it is now reaching the critical latitude point. “The sunspot cycle is about to take off,” [Hill] adds, based on the latest solar jet stream measurements [USA Today].

As for why the jet stream was moving slower than usual–well, researchers don’t have an answer for that yet. But there are a lot of things that researchers don’t yet understand about the sun’s behavior. To try to answer some questions, another group of researchers has also created the first ever model of an entire sunspot (pictured), using a supercomputer to calculate its dynamics, crunching data from 1.8 billion individual points. The model, described in a paper in Science, may help explain both earthly and solar phenomenon. Says lead researcher Matthias Rempel: “If you want to understand all the drivers of Earth’s atmospheric system, you have to understand how sunspots emerge and evolve.” … Solar flares and coronal mass ejections are typically found in magnetically active regions around groupings of sunspots. These plasma storms can buffet the Earth’s atmosphere and disrupt power grids, satellites and other systems [Live Science].

Related Content:
Bad Astronomy: Here comes the Sun(spot)! has more on the recent sunspot findings
80beats: New Images Herald an Improved Solar-Storm Early Warning System
DISCOVER: Space Weather and the havoc it can cause
DISCOVER: Seeing Sun Storms in Stereo

Image: UCAR / Matthias Rempel, NCAR

CATEGORIZED UNDER: Physics & Math, Space
  • J Gary Fox

    As one who has followed the travils of trying to first forecast Cycle 24 and then explain the dearth of sunspots,I am somewhat sceptical about this new theory.

    It was only a few years ago when the experts predicted a very intense Cycle 24 based on their accuracy in prediction Cycle 23.

    “Oct. 19, 1998: Scientists at NASA’s Marshall Space Flight Center appear to have done a good job of predicting Cycle 23 of the sunspot cycle.

    “They expect Cycle 23 to continue until sometime in 2006 when the next cycle, Cycle 24, should begin.”

    Too bad the Sun wasn’t invested in the theory.

    No expert predicted the late start of Cycle 24 … if indeed it can be “declared” started … nor the deep quiet phase of the sun in all mesurable energies.

    We live in exciting Solar times … stay tuned for the conclusion of Cycle 24 … and, if possible, Cycle 25.

  • torres

    Hey JGary Fox, I am curious to know more about what you are talking about. Can you explain it better?

  • Roberto Ruth

    Agreed, please go on.

  • Jared Wain Jarvi

    Important stuff to know,science is best when it can help keep a look out at saving our bacon and in this case the bacon to be fride is US.

  • roy norton

    Al Gore should be feeling pretty dumb about now!

  • John

    Unfortunately, this is an area where politics and science mix, and one disrupts the other.

    It is not politically correct to say that the sun might have a bigger impact on the earth’s climate than greenhouse gasses. An open-minded scientist evaluating the evidence risks being branded a “denier”, unless he says something bad about carbon to placate the ignorant masses.

    If you want to learn more, look up the Wikipedia entry for “Maunder Minimum”. This is not the first time that sunspots have suddenly disappeared.

    The truth is, there is a lot that don’t know.

  • Jack

    5. roy norton Says:
    June 22nd, 2009 at 1:25 am

    Al Gore should be feeling pretty dumb about now!

    hmm.. really. should he? and why exactly?

  • Candy

    The first thing I thought of while reading this article was a phrase my mother used occasionally…it’s the “lull before the storm”.

  • Franklin

    Al Gore is an unabashed opportunist not a scientist, just another inconvenient truth.

  • Charlie

    torres — if you want more info go to The forums there will lead you to the several old forecasts for cycle 24.

    To see what an EPA scientist wanted to say about their recent report, but was prohibited from saying because “the administrator and the administration have already decided on the endangerment path”, go to

    A comment filing that includes e-mails detailing the supression of dissent can be found at


    Debate is good and strengthens ideas that are correct.

    The “the science is settled” position that many anthropogenic global warming activists take is an indication of the weakness of the science behind their position.

  • Bluejay

    Of course the sun is the primary factor that influences our weather. No one would ever dream of denying that obvious fact. However other factors play a huge role in how the sun’s energy is absorbed or reflected. It so happens we are responsible for pumping millions of tons of excess carbon that is retaining the solar energy. That is the only factor we can control.

  • JF

    The sun influences the clouds which directly drives the weather. Humans release CO2 from the natural sources within which it resides. The Oceans are to name but one natural sponge which contain a vast amount of stored CO2 which in noteably colder periods they release (and store in warmer periods — a sfety valve of sorts)….The volume of CO2 which humans release from natural sources is from information i’ve seen (but then again who can you believe) in no comparison to the amount released by the planets volcano’s. If CO2 is going to scorch the earth, how ever did we survive the periods of extreme volcanic actvity….oh, there was an ice age wasn’t there when things cooled down a bit?. Every living thing has a pattern, a cycle if you will. Who are we to assume that planets are any exception and that we can in anyway imaginable effect something which has been happening since the dawn of time of itself. Solar minimums and solar maximums are our interpretation of what we think know…..not necessarily what is actually happening.
    Just the thoughts of a lay man, trying to make sense of it all…..;-()

  • Before Gore Kneel

    Wear a hairshirt and walk where you need to go. Revenge is within my grasp.

  • John A. Jauregui

    Google “Rhoads Fairbridge solar inertial motion” to get a better understanding of just what is going on with regard to the sun and its impact on our climate.

  • The Baldchemist

    Ah, “God moves in strange ways”. The Lord giveth and the Lord taketh away.

    It must be God’s work if science can’t explain it eh?

  • Ralph Smith

    This is really helpful to those of us who are interested but lack the training and know-how to get access to more complete information. I’m looking forward to more of this.

  • Pandora Bracelets

    I together with my guys ended up going through the good helpful tips located on your website and then quickly got an awful suspicion I had not expressed respect to the website owner for those tips. All the men ended up certainly stimulated to learn all of them and have now simply been having fun with these things. Thank you for actually being quite considerate and also for going for variety of brilliant resources most people are really desperate to discover. My personal honest regret for not expressing appreciation to earlier.


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles covering the day's most compelling topics.

See More

Collapse bottom bar