SB PROP @ ARL $ARLP029   
   ARLP029 Propagation de K7RA   
      
   ZCZC AP29   
   QST de W1AW     
   Propagation Forecast Bulletin 29  ARLP029   
   From Tad Cook, K7RA   
   Seattle, WA  July 22, 2011   
   To all radio amateurs    
      
   SB PROP ARL ARLP029   
   ARLP029 Propagation de K7RA   
      
   Average daily sunspot numbers for the week rose nearly 27 points to   
   92.4, while average daily solar flux increased over 9 points to   
   98.2.  The latest prediction has solar flux values for the next week   
   a little lower than those listed in Thursday's ARRL Letter.   
   Expected values are 96 for today, July 22, then 95 on July 23-27, 98   
   on July 28, 90 on July 29 through August 2, 95 on August 3-7, 98 on   
   August 8, and back to 100 on August 9-16.   
       
   Planetary A index for July 22-23 is predicted at 10 and 8, then 5 on   
   July 24-28, 8 on July 29-31, then 10, 8, 5 and 8 on August 1-4, 12   
   on August 5-7, and 8 on August 8-10.   
       
   Geophysical Institute Prague has a weekly prediction for geomagnetic   
   indices that doesn't use the A or K index, but instead has seven   
   levels of activity, from quiet to severe storm.  Their prediction   
   for this week says to expect unsettled conditions for today, July   
   22, quiet to unsettled on July 23, quiet July 24-25, quiet to   
   unsettled July 26-27, and quiet again on July 28.   
       
   There seem to be plenty of sunspots visible over the past week, but   
   nothing really large or very active.  Sunspot areas are counted in   
   millionths of a solar hemisphere, and on Thursday, July 14, there   
   were six sunspot groups visible:  1245, 1250, 1251, 1252, 1254 and   
   1255.  The area ranged from 5 for sunspot group 1245 to 100 each for   
   groups 1250 and 1251.  Total sunspot area for that day was 265.   
       
   On Friday, July 15, a new sunspot group 1256 was added, and total   
   sunspot area was 260, as the other sunspot groups shrank, except for   
   1251 and 1254.  On July 16, 1255 disappeared, and total sunspot area   
   dropped to 230.  On Sunday, July 17, sunspot areas 1245 and 1252   
   disappeared, new group 1257 was added, and total sunspot area grew   
   to 280.   
       
   On Monday, July 18 sunspot area jumped to 400 when two new groups,   
   1258 and 1259 were added.  On July 19 sunspot area jumped again to   
   660, when 1255 disappeared and all sunspot groups except 1256 grew.   
   1250, 1257 and 1258 each doubled in size, while 1259 more than   
   tripled.   
       
   On July 20, 1256 and 1257 disappeared, and sunspot area dropped by   
   more than half to 310.  Yesterday, July 21, 1250 and 1258 went away,   
   and sunspot area declined from 310 to 290, and daily sunspot number   
   declined from 79 to 56.   
       
   There has been quite a bit of news about a predicted grand minima in   
   solar activity.  We recently reported on a conference in which three   
   lines of evidence were presented which seemed to point to a future   
   disappearance of sunspots, perhaps like the dreaded Maunder Minimum.   
       
   I am not unbiased in this regard, and like most amateur radio   
   operators yearn for high solar activity.  Alas, a return of cycle   
   19, the granddaddy of them all, seems elusive.  But there is some   
   dissent regarding these predictions of no sunspots, which gives us   
   hope.   
       
   On Wednesday I spoke with Dr. Douglas Biesecker, an astrophysicist   
   at the NOAA Space Environment Center in Boulder.  He was mentioned   
   in ARLP024 (see http://www.arrl.org/w1aw-bulletins-archive/ARLP024/2011)    
   as dissenting from the assertion that evidence points toward sunspots    
   disappearing or another Maunder Minimum in our future.   
       
   He mentioned something called a Gleissberg Cycle.  What happens when   
   we do a really long smoothing of sunspot numbers?  The smoothed   
   sunspot numbers we are familiar with, the data used in those nice   
   graphs of sunspot cycles, average data over 13 months.  So every   
   place you look on the graph doesn't show the variation that occurred   
   during that month, but instead averages data over more than a year,   
   to smooth out all the noise of daily variations.   
       
   But what would happen if you smoothed the numbers over a much longer   
   period, say 11 years?  Could you find some periodicity that would   
   suggest a cycle of cycles, or perhaps predict clusters of decades   
   with low or high solar activity?   
       
   Gleissberg cycles suggest a periodicity of about 87 years, and some   
   have studied these to try to predict general levels of solar   
   activity over multiple decades.  But if a cycle is 87 years long,   
   and we only have about 256 years of directly observed solar data,   
   the most we could look at would be less than three cycles.  That   
   isn't enough data to make even crude speculative projections.   
       
   Doug mentioned what he referred to as an "old NASA axiom", that goes   
   something like this:  If you can't see something happen seven times,   
   it isn't real.   
       
   Doug said he is attending SHINE workshops, and SHINE is an acronym   
   for Solar Heliospheric and Interplanetary Environment (see   
   http://shinecon.org/).  At these meetings participants have been   
   hashing out the evidence for or against a "no cycle 25" scenario,   
   and discovering some problems with the three lines of evidence   
   pointing toward a disappearance of sunspots.  They haven't reached a   
   consensus, but he believes that positions may be moving away from   
   predicting another Maunder Minimum.   
       
   On this topic, take a look at this website:   
   http://www.thesuntoday.org/current-observations/solar-hibernatio   
   -much-ado-about   
   -nothing/.   
       
   A new issue of WorldRadio is available on the twentieth of each   
   month, and on July 20 the August 2011 issue was out.  You can get   
   one at http://www.worldradiomagazine.com/ and on page 20 you'll find   
   the monthly Propagation column by Carl Luetzelschwab, K9LA.  This   
   time it is titled "Here's Some Help to Explain Those Unusual QSOs".   
   Carl looks at propagation that doesn't seem to be supported by the   
   MUF or general level of solar activity at the time, and offers some   
   interesting ideas on what might really be going on.   
       
   If you are fortunate enough to be in Kansas City this weekend, you   
   can catch Carl's talk on propagation at W0DXCC-2011 on Saturday,   
   July 23.  His talk begins at 9:30 AM in the W0JM Room, and is titled   
   "Our Recent Sunspot Minimum, and the new Sunspot Cycle 24".  Check   
   http://www.w0dxcc.com/ for details.   
        
   If you would like to make a comment or have a tip for our readers,   
   email the author at, k7ra@arrl.net.   
       
   For more information concerning radio propagation, see the ARRL   
   Technical Information Service at   
   http://arrl.org/propagation-of-rf-signals.  For an explanation of   
   the numbers used in this bulletin, see   
   http://arrl.org/the-sun-the-earth-the-ionosphere.  An archive of   
   past propagation bulletins is at   
   http://arrl.org/w1aw-bulletins-archive-propagation.  Find more good   
   information and tutorials on propagation at   
   http://mysite.ncnetwork.net/k9la/index.html.   
       
   Monthly propagation charts between four USA regions and twelve   
   overseas locations are at http://arrl.org/propagation.   
       
   Instructions for starting or ending email distribution of ARRL   
   bulletins are at http://arrl.org/bulletins.   
       
   Sunspot numbers for July 14 through 20 were 79, 90, 75, 101, 127,   
   96, and 79, with a mean of 92.4.  10.7 cm flux was 94.1, 93.8, 93.8,   
   103.6, 102, 100.3, and 100.1, with a mean of 98.2.  Estimated   
   planetary A indices were 8, 6, 6, 5, 8, 18, and 19, with a mean of   
   10. Estimated mid- latitude A indices were 6, 5, 4, 3, 6, 10, and   
   12, with a mean of 6.6.   
   NNNN   
   /EX   
      
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   Gentlemens' agreements ratified by IARU regions 1 and 2 have   
   designated a global "center of activity" frequency  in  each   
   of  the  international  hf  bands.  THese are similar to the   
   concept for weak signal calling and other center of activity   
   frequencies.  Three of these have been ratified worldwide.   
      
   THese  center of activity frequencies are where stations can   
   go to render or obtain emergency assistance.   
      
   WHen casually operating or  contesting  on  hf  please  make   
   yourself  aware  of  these  frequencies,  and give them some   
   space. Remember that often stations with emergency needs are   
   not  those  utilizing  high  gain antennas and maximum legal   
   power.   
      
   TO find out more, visit 14300.net or IARU web resources.   
      
      
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