A lot of speculation has been circulating about how the current solar cycle minimum is going to last years and years, like another "Maunder Minimum" of 1645-1715. I have commented before that I don't believe in these dismal forecasts. The research being revealed recently, as well as the current increase in sunspot activity, bears out my prognosis: the new Cycle 24 is alive and sunspot activity will pick up energy as 2009 progresses forward.

So, what is science telling us? Why has Cycle 24 been so slow in starting? The answer, in part, is that the mechanisms within the complex Sun are just a bit slower this time around than in the last few solar cycle minimums. One major part of this dynamic mechanism is the Sun's jet stream.

Did you know that the sun has jet streams? Recent research now reveals a powerful dynamic deep inside the sun. Scientists from the National Solar Observatory (NSO) in Tucson, Arizona have discovered that deep inside the sun a powerful solar jet stream migrates through the star's interior.

During this current solar cycle minimum, this solar jet stream moved more slowly than in recent past minimum periods. This appears to be the underlying reason for the long period that lacked sunspots and prolonged the solar minimum. The scientists involved in this discovery presented their research at the meeting of the Solar Physics Division of the American Astronomical Society (AAS/SPD) in June 2009.

Drs. Rachel Howe and Frank Hill, both of the NSO, used long-term observations from the NSO's Global Oscillation Network Group (GONG) facility to detect and track an east-to-west jet stream, known as the "torsional oscillation," at depths of about 1000 to 7000 km below the surface of the sun. The sun generates new jet streams near its poles every 11 years; the streams migrate slowly, over a period of 17 years, to the equator and are associated with the production of sunspots once they reach a critical latitude of 22 degrees.

Howe and Hill found that the stream associated with the new solar cycle has moved sluggishly, taking three years to cover a 10-degree range in latitude, compared to two years for the last solar cycle, but has now reached the critical latitude. The current solar minimum has become so long and deep that some scientists have speculated the sun might enter a long period with no sunspot activity at all.

The new result shows both that the Sun's internal magnetic dynamo continues to operate and heralds the beginning of a new cycle of solar activity. "It is exciting to see," said Dr. 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 at the new active latitude." Since the current minimum is now one year longer than usual, Howe and Hill conclude that the extended solar minimum phase may have resulted from the slower migration of the flow.

Now that this solar jet stream has reached the 'critical' latitude, are we seeing a rise in the number of sunspots? Yes, and the period between sunspot emergences is becoming shorter and shorter. For instance, during the month of June 2009, sunspots were observed on 13 days of the month. Then, starting on July 3, another new Cycle 24 sunspot emerged, daily growing in size and unleashing numerous flares. By the 5th of July, and for the first time in the new cycle, a C-class flare erupted. By July 6th, it was clear that this sunspot group was influencing radio propagation, as the 10.7-cm flux rose above 70, and subtle changes in various modes of propagation were observed. This sunspot group comes as part of a series of new sunspots, indicating that the new cycle is certainly alive and gaining in strength.

Indeed, Sunspot Cycle 24 is increasing in energy and we're in for a nice rise in ionospheric energy. The next few years will be alive with activity.

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Anonymous   |68.83.233.xxx |2009-07-11 11:28:52 Most of the July sunspot activity is related to one small group which is now disappearing behind the sun’s limb. Nothing is emerging and the sunspot count may again drop to zero. As one who has followed the travails of the experts trying to first forecast Cycle 24 and then trying to explain the dearth of sunspots, I am somewhat skeptical about this new “jet stream” theory. It was only a few years ago when the experts predicted a very intense Cycle 24 based on their “theories” and their proven accuracy in predicting the intensity of Cycle 23. http://science.nasa.gov/newhome/headlines/ast19oct98_1.htm "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 or the deep quiet phase of ... Reply 0 0

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