[SFDXA] ARLP037 Propagation de K7RA

[William Marx]

> SB PROP @ ARL $ARLP037
> ARLP037 Propagation de K7RA
> 
> ZCZC AP37
> QST de W1AW  
> Propagation Forecast Bulletin 37  ARLP037
> From Tad Cook, K7RA
> Seattle, WA  September 9, 2016
> To all radio amateurs 
> 
> SB PROP ARL ARLP037
> ARLP037 Propagation de K7RA
> 
> Compared to the last reporting week, this week (September 1-7)
> average daily sunspot numbers were down, solar flux increased, and
> geomagnetic indices were much more active.
> 
> Average daily sunspot number declined from 60.1 to 46.4, while
> average solar flux went from 87.9 to 95.1. Average planetary A index
> increased from 8 to 26.6, while average mid-latitude A index rose
> from 6.9 to 18.1.
> 
> The daily planetary A index on September 1-4 was 36, 39, 40 and 28.
> It looks like an echo of the solar wind which caused this activity
> is expected on September 28 through October 1, when the predicted
> planetary A index is 35, 38, 40 and 25.
> 
> Predicted solar flux is 95 on September 9-10, then 92, 90, and 85 on
> September 11-13, 80 on September 14-16, 108 on September 17-19, then
> 110, 105 and 110 on September 20-22, 112 on September 23-24, 108 on
> September 25, 105 on September 26-27, 100 on September 28, 95 on
> September 29 through October 1, 98 on October 2-4, 95 on October
> 5-6, 90 on October 7-8, 95 on October 9, 100 on October 10-11, 105
> on October 12, and 108 on October 13-16. After October 16 flux
> values meander from 105 to 112.
> 
> On September 5 predicted solar flux values for September 13 to
> October 21 got a big boost, a predicted increase ranging from 18-30
> points from the September 4 prediction.
> 
> Predicted planetary A index is 15 on September 9, 8 on September
> 10-11, 10 on September 12, 8 on September 13-15, 5 on September
> 15-16, then 8, 5, 15, 12 and 8 on September 17-21, 5 on September
> 22-25, then 12, 8, 35, 38 and 40 on September 26-30, then 25, 20 and
> 12 on October 1-3, 10 on October 4-5, 5 on October 6-9, then 10, 8,
> 5, 5, 8, 5, 15, 12 and 8 on October 10-18, and 5 on October 19 and
> beyond.
> 
> Petr Kolman, OK1MGW of the Czech Propagation Interest Group predicts
> the geomagnetic field will be:
> 
> Quiet on September 23-24
> Mostly quiet on September 9-11, 14-16, 18, 22, October 5
> Quiet to unsettled on September 12, 17, 21, 25, 27, October 3-4
> Quiet to active on September 13, 19-20, 26, 28-30, October 1-2
> Active to disturbed on September (29-30)
> 
> Increased solar wind from coronal holes is expected on September
> 12-13, 17, 19-21, 25-26, 28-30, October 1-2
> 
> Remarks: - Parenthesis means lower probability of activity
> enhancement.
> 
> Propagation expert Carl Luetzelschwab, K9LA gave a talk (via the
> Internet) to the World Wide Radio Operator's Foundation on August
> 23, as reported this week on the ARRL web site:
> 
> http://bit.ly/2c3yMbZ
> 
> Also note the link in the article to Carl's presentation to the
> club, "Solar Topics - Where We're Headed." See/hear it at
> http://bit.ly/2ceGTiE .
> 
> Carl notes that some forecasters of space weather have predicted
> smaller solar cycles in the future. But personally, I would not be
> so sure (I'm always searching for something to be positive about,
> when it relates to future solar activity).
> 
> Check out this presentation by Douglas Biesecker, Chair of the Solar
> Cycle 24 Prediction Panel, http://bit.ly/2cz5zkD, which does not
> predict low solar activity extending decades into the future.
> 
> Note also that Carl predicts a future Cycle 25 at least as strong as
> Cycle 24.
> 
> Carl also mentioned a number I had not heard before. He notes that
> many solar cycles in the past have been equivalent to Cycle 19, the
> biggest sunspot cycle experienced by anyone still alive today. He
> projects back over the past 11,000 years, and with the number he
> gives, the next grand maximum after Cycle 19 in the late 1950s might
> be around year 2537 AD. Note that Carl did not predict this. I am
> just trying to extrapolate from the numbers he mentioned, to get
> some very rough idea of how uncommon Cycle 19 was.
> 
> His numbers show that over the past 11,000 years, 19 notable grand
> maximums - including Cycle 19 and the cycles around it - and 27
> notable grand minimums were recorded. "We're likely to have more of
> both grand maximums and grand minimums in the future," he predicted.
> But arithmetically estimated from 19 maximums in 11,000 years, that
> puts the next big one (after Cycle 19) at 521 years from now, maybe
> in Cycle 71.
> 
> Finally, we received a note from Dick Ferry, K2KA of Westford,
> Massachusetts concerning 6-meter auroral propagation on September 3:
> 
> "Some notes of last night's brief AU opening.
> 
> "Got up at 1230am (0430Z) Sep 3, saw AU activity on 6M.
> 
> "I heard KL7NO on 50.1056 MHz.  He was very weak, barely copiable
> but I did hear him. Didn't call him as he was only audible for a few
> seconds.
> 
> "That would have been awesome!
> 
> "Did call CQ for about 5 min.
> 
> "K0KP/B, N8PUM/B and VE4VHF/B were loud. But no humans on the band.
> The beacons were gone in about 10 min.
> 
> "73, Dick K2KA (formerly AB1A)."
> 
> Thanks Dick!
> 
> If you would like to make a comment or have a tip for our readers,
> email the author at k7ra at arrl.net.
> 
> For more information concerning radio propagation, see the ARRL
> Technical Information Service web page 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 September 1 through 7 were 66, 50, 46, 59, 22,
> 32, and 50, with a mean of 46.4. 10.7 cm flux was 95.2, 94.6, 99,
> 97.4, 93.8, 92.4, and 93, with a mean of 95.1. Estimated planetary A
> indices were 36, 39, 40, 28, 17, 14, and 12, with a mean of 26.6.
> Estimated mid-latitude A indices were 29, 24, 21, 20, 13, 12, and 8,
> with a mean of 18.1.
> NNNN
> /EX