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Posted on 06/17/2009 4:57:29 PM PDT by decimon
The sun is in the pits of a century-class solar minimum, and sunspots have been puzzlingly scarce for more than two years. Now, for the first time, solar physicists might understand why.
At an American Astronomical Society press conference today in Boulder, Colorado, researchers announced that a jet stream deep inside the sun is migrating slower than usual through the star's interior, giving rise to the current lack of sunspots.
Rachel Howe and Frank Hill of the National Solar Observatory (NSO) in Tucson, Arizona, used a technique called helioseismology to detect and track the jet stream down to depths of 7,000 km below the surface of the sun. The sun generates new jet streams near its poles every 11 years, they explained to a room full of reporters and fellow scientists. The streams migrate slowly from the poles to the equator and when a jet stream reaches the critical latitude of 22 degrees, new-cycle sunspots begin to appear.
Howe and Hill found that the stream associated with the next solar cycle has moved sluggishly, taking three years to cover a 10 degree range in latitude compared to only two years for the previous solar cycle.
The jet stream is now, finally, reaching the critical latitude, heralding a return of solar activity in the months and years ahead.
"It is exciting to see", says Hill, "that just as this sluggish stream reaches the usual active latitude of 22 degrees, a year late, we finally begin to see new groups of sunspots emerging."
The current solar minimum has been so long and deep, it prompted some scientists to speculate that the sun might enter a long period with no sunspot activity at all, akin to the Maunder Minimum of the 17th century. This new result dispells those concerns. The sun's internal magnetic dynamo is still operating, and the sunspot cycle is not "broken."
Because it flows beneath the surface of the sun, the jet stream is not directly visible. Hill and Howe tracked its hidden motions via helioseismology. Shifting masses inside the sun send pressure waves rippling through the stellar interior. So-called "p modes" (p for pressure) bounce around the interior and cause the sun to ring like an enormous bell. By studying the vibrations of the sun's surface, it is possible to figure out what is happening inside. Similar techniques are used by geologists to map the interior of our planet.
In this case, researchers combined data from GONG and SOHO. GONG, short for "Global Oscillation Network Group," is an NSO-led network of telescopes that measures solar vibrations from various locations around Earth. SOHO, the Solar and Heliospheric Observatory, makes similar measurements from Earth orbit.
"This is an important discovery," says Dean Pesnell of NASA's Goddard Space Flight Center. "It shows how flows inside the sun are tied to the creation of sunspots and how jet streams can affect the timing of the solar cycle."
There is, however, much more to learn.
"We still don't understand exactly how jet streams trigger sunspot production," says Pesnell. "Nor do we fully understand how the jet streams themselves are generated."
To solve these mysteries, and others, NASA plans to launch the Solar Dynamics Observatory (SDO) later this year. SDO is equipped with sophisticated helioseismology sensors that will allow it to probe the solar interior better than ever before.
Right: An artist's concept of the Solar Dynamics Observatory. [more]
"The Helioseismic and Magnetic Imager (HMI) on SDO will improve our understanding of these jet streams and other internal flows by providing full disk images at ever-increasing depths in the sun," says Pesnell.
Continued tracking and study of solar jet streams could help researchers do something unprecedented--accurately predict the unfolding of future solar cycles. Stay tuned for that!
SUV’s and Bush?
SUVs on the sun are emitting hydrocarbons that cause cooling.
.....crickets.....
/johnny
Correlation is not causation. What will happen if the jet stream hits the equator and there are still no sun spots?
He forgot to add that there have been no "groups" reported, and even most of the handful of sunspots they've reported are questionable ~ mini-sunspots at best, or maybe burbles or something ~ not the real stuff.
These people are so desperate they are now demanding we start believing in magical jetstreams full of sunspots.
My word! They are mad.
Wow,I’m shocked
Not a single word about that scam called global warming
He said that when the jet streams reach 22 degrees then, a year later, we will see groups of sunspots.
I am also ready and would even like a good opening on 15 meters.
73 de
Then the scientists will be back to making up a new theory. They will call it “We don’t know jack”
/johnny
So now the mystery isn’t the puzzling scarcity of sun spots, but the tardy, sluggish jet stream deep inside the sun’s interior? Do the same scientists think they know why that stream’s slowed?
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Sonograms Of The Sun Explain Mystery Of The Missing Sunspots
This is no demonstrable item BTW. The observations the theory is based on have not even occurred over half a solar cycle.
You were aware all the "sunspot watcher" sites have begun referring to the NASA reports on sunspots as "official sunspot sighting" ~ as if those reports were nothing other than propaganda.
No doubt they imagine that Hanumon like creatures (space monkeys) are PULLING on it to trick humans into thinking the Sun is cooling down a bit.
Can you imagine that jet stream? The jet stream of hell.
Barely. I think the magnitude exceeds my comprehension.
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