Solar Cycle Update: Twin Peaks?   
       
   March 1, 2013: Something unexpected is happening on the sun.  2013 is supposed   
   to be the year of Solar Max, the peak of the 11-year sunspot cycle. Yet 2013   
   has arrived and solar activity is relatively low.  Sunspot numbers are well   
   below their values in 2011, and strong solar flares have been infrequent for   
   many months.   
       
   The quiet has led some observers to wonder if forecasters missed the mark.   
   Solar physicist Dean Pesnell of the Goddard Space Flight Center has a   
   different explanation:   
       
   "This is solar maximum," he suggests. "But it looks different from what we   
   expected because it is double peaked."   
       
   http://www.youtube.com/watch?v=6j4bl57D_1U   
       
   A new ScienceCast video explores the puzzling behavior of ongoing Solar Cycle   
   24. Play it   
       
   Conventional wisdom holds that solar activity swings back and forth like a   
   simple pendulum.  At one end of the cycle, there is a quiet time with few   
   sunspots and flares.  At the other end, Solar Max brings high sunspot numbers   
   and solar storms. It's a regular rhythm that repeats every 11 years.   
       
   Reality, however, is more complicated. Astronomers have been counting sunspots   
   for centuries, and they have seen that the solar cycle is not perfectly   
   regular. For one thing, the back-and-forth swing in sunspot counts can take   
   anywhere from 10 to 13 years to complete; also, the amplitude of the cycle   
   varies.  Some solar maxima are very weak, others very strong.   
       
   Pesnell notes yet another complication: "The last two solar maxima, around   
   1989 and 2001, had not one but two peaks."  Solar activity went up, dipped,   
   then resumed, performing a mini-cycle that lasted about two years.   
       
   The same thing could be happening now.  Sunspot counts jumped in 2011, dipped   
   in 2012, and Pesnell expects them to rebound again in 2013: "I am comfortable   
   in saying that another peak will happen in 2013 and possibly last into 2014,"   
   he predicts.   
       
   Another curiosity of the solar cycle is that the sun's hemispheres do not   
   always peak at the same time.  In the current cycle, the south has been   
   lagging behind the north.  The second peak, if it occurs, will likely feature   
   the southern hemisphere playing catch-up, with a surge in activity south of   
   the sun's equator.   
       
   http://science.nasa.gov/media/medialibrary/2013/03/01/shortfall.jpg   
       
   Recent sunspot counts fall short of predictions. Credit: Dr. Tony Philips &   
   NOAA/SWPC [full plot] Pesnell is a leading member of the NOAA/NASA Solar Cycle   
   Prediction Panel, a blue-ribbon group of solar physicists who assembled in   
   2006 and 2008 to forecast the next Solar Max. At the time, the sun was   
   experiencing its deepest minimum in nearly a hundred years.  Sunspot numbers   
   were pegged near zero and x-ray flare activity flat-lined for months at a   
   time.  Recognizing that deep minima are often followed by weak maxima, and   
   pulling together many other threads of predictive evidence, the panel issued   
   this statement:   
       
   "The Solar Cycle 24 Prediction Panel has reached a consensus. The panel has   
   decided that the next solar cycle (Cycle 24) will be below average in   
   intensity, with a maximum sunspot number of 90. Given the date of solar   
   minimum and the predicted maximum intensity, solar maximum is now expected to   
   occur in May 2013. Note, this is not a unanimous decision, but a supermajority   
   of the panel did agree."   
       
   Given the tepid state of solar activity in Feb. 2013, a maximum in May now   
   seems unlikely.   
       
   "We may be seeing what happens when you predict a single amplitude and the Sun   
   responds with a double peak," comments Pesnell.   
       
   Incidentally, Pesnell notes a similarity between Solar Cycle 24, underway now,   
   and Solar Cycle 14, which had a double-peak during the first decade of the   
   20th century. If the two cycles are in fact twins, "it would mean one peak in   
   late 2013 and another in 2015."   
       
   No one knows for sure what the sun will do next.  It seems likely, though,   
   that the end of 2013 could be a lot livelier than the beginning.   
       
       
   Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.9   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)