[SFDXA] ARLP034 Propagation de K7RA

[William Marx]

> 
> SB PROP @ ARL $ARLP034
> ARLP034 Propagation de K7RA
> 
> ZCZC AP34
> QST de W1AW  
> Propagation Forecast Bulletin 34  ARLP034
> From Tad Cook, K7RA
> Seattle, WA  August 19, 2016
> To all radio amateurs 
> 
> SB PROP ARL ARLP034
> ARLP034 Propagation de K7RA
> 
> Conditions turned a little more favorable since last week's bulletin
> with both solar flux and sunspot numbers up, and geomagnetic indices
> substantially lower.
> 
> Average daily sunspot numbers for the August 11 to 17 period were
> 73.9, compared to 52 for the previous seven days.  Average daily
> solar flux went from 87.9 to 89.2.  Average daily planetary A index
> dropped from 14.6 to 6.9, and average mid-latitude A index went from
> 13.7 to 7.4.
> 
> Predicted solar flux for the near term is 85 on August 19, 80 on
> August 20, 75 on August 21 and 22, 85 on August 23 and 24, 90 on
> August 25 and 26, 75 on August 27 through September 1, 80 and 85 on
> September 2 and 3, and 90 on September 4 to 14.  Solar flux then
> pulls back to 75 on September 18 to 28, then recovers to 90 in the
> first days of October.
> 
> Predicted planetary A index is 10, 14, 8 and 6 on August 19 to 22, 5
> on August 23 and 24, 12 on August 25, 8 on August 26, 5 on August 27
> and 28, then 15, 25 and 18 on August 29 to 31, 15 on September 1 and
> 2, 12 on September 3 and 4, and 15 on September 5 and 6.
> 
> The predicted planetary A index is 25 on September 26, indicating
> high geomagnetic activity.
> 
> We have a geomagnetic forecast from F. K. Janda, OK1HH. 
> 
> The geomagnetic field will be, 
> Quiet on August 22, 27 and 28, September 10 to 12 
> Mostly quiet on August 19, 23, 26, September 9 
> Quiet to unsettled on August 20, September 1, 13 
> Quiet to active on August 21, 24 and 25, 31, September 2 to 8, 14 
> Active to disturbed on August 29 and 30 
> 
> Increases of solar wind from coronal holes are expected on August
> (24 and 25, 29,) 30 and 31, September 1, (2 to 5)
> 
> Remark: 
> - Parenthesis means lower probability of activity enhancement. 
> 
> Thanks to David Moore for sending this article about the Van Allen
> belt.
> 
> http://bit.ly/2bCqHXb 
> 
> Note that it mentions a big geomagnetic storm last year on March 17,
> so I thought it would be interesting to see what the numbers looked
> like.
> 
> http://bit.ly/2bOuEMu 
> 
> Those are some big numbers indicating a big disturbance.  Note also
> that the middle column, which is data for Alaska's College A index
> shows that the instruments were offline or there was some kind of
> problem gathering data in the four days preceding the big numbers.
> Unsure if this had anything to do with the impending storm, or if
> they just got lucky and had everything back online by the day of the
> big event.
> 
> Don't miss the link half way down the right side of the page on the
> Van Allen article, titled "Chemtrails Not Real, Say Atmospheric
> Science Experts."  Nothing to do with radio or propagation, but it
> has some interesting facts about a popular belief that I regard as
> popular folklore.
> 
> I noticed in yesterday's ARRL DX bulletin that there are a lot of
> scheduled island (IOTA) and lighthouse operations coming up this
> weekend and beyond.
> 
> 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.  More good
> information and tutorials on propagation are at http://k9la.us/.
> 
> 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 August 11 through 17 were 82, 86, 73, 61, 70,
> 81, and 64, with a mean of 73.9. 10.7 cm flux was 94.7, 94.8, 90.5,
> 87.2, 87.6, 86.5, and 82.9, with a mean of 89.2.  Estimated
> planetary A indices were 9, 11, 5, 4, 4, 6, and 9, with a mean of
> 6.9. Estimated mid-latitude A indices were 8, 11, 5, 4, 4, 8, and 12
> with a mean of 7.4.
> NNNN
> /EX