[SFDXA] ARLP032 Propagation de K7RA

[Bill]

> SB PROP @ ARL $ARLP032
> ARLP032 Propagation de K7RA
> 
> ZCZC AP32
> QST de W1AW  
> Propagation Forecast Bulletin 32  ARLP032
> From Tad Cook, K7RA
> Seattle, WA  August 11, 2023
> To all radio amateurs 
> 
> SB PROP ARL ARLP032
> ARLP032 Propagation de K7RA
> 
> Two new sunspot groups appeared on August 3, three more on August 7,
> and another on August 9.
> 
> But solar activity was lower over our reporting week, August 3-9,
> with average daily sunspot number dropping from 154.3 to 108.9 and
> average solar flux from 173 to 166.4.
> 
> Average daily planetary A index rose from 8.3 to 12.3 and average
> middle latitude A index from 9.3 to 10.1.
> 
> The middle latitude A index numbers on August 3-4 were not
> available, and are my estimates, tracking with the planetary A index
> and the remaining five middle latitude readings in the rest of the
> week.
> 
> Predicted solar flux is 150 on August 11-12, then 145, 140 and 130
> on August 13-15, 135 on August 16-17, 162 on August 18, 164 on
> August 19-20, 168 on August 21-23, then 172, 172 and 170 on August
> 24-26, 172, 172 and 174 on August 27-29, then 172, 172 and 170 on
> August 30 through September 1, then 168, 168, 166 and 164 on
> September 2-5, then 162, 162, 164 and 164 on September 6-9, then
> 162, 162 and 160 on September 10-12, 162 on September 13-14, 164 on
> September 15-16, and 168 on September 17-19.
> 
> Predicted planetary A index is 5 on August 11 13, then 8, 12, 12 and
> 10 on August 14-17, 5 on August 18-25, 12 on August 26, then 5 on
> August 27 through September 4, 12 on September 5, and 5 on September
> 6-21.
> 
> On August 9 Spaceweather.com wrote about a geomagnetic storm in 1940
> that sounds similar to the infamous Carrington Event. Two CMEs hit
> Earth 109 minutes apart. Here is a recent scientific paper on the
> event: https://bit.ly/3s1VrMh .
> 
> Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
> Ionosphere August 11-17, 2023 from OK1HH.
> 
> Sometimes you need to take a break and that's why this time the
> commentary covers the last two weeks instead of one. During these
> weeks, solar activity was often elevated.
> 
> M and X class flares and CMEs occurred frequently. The Earth was
> lucky not to be hit by the fiery loop that ejected from the Sun from
> AR3372 during the M4-class eruption on October 28 at 1558 UTC.
> Energetic protons from the Sun were hitting Earth's atmosphere for a
> significant part of the period (a "radiation storm" - class S1). The
> source this time was beyond the northwestern edge of the solar disk
> and was most likely an X-class flare. The consequence was also
> absorption in the polar cap (PCA).
> 
> On August 1, the CME was very likely to hit the Earth's magnetic
> field, but instead we only registered a hint of a near-Earth flyby
> around 1600 UTC. We expected another CME arrival and a smaller G1
> class geomagnetic storm on August 4-5. It happened, and the magnetic
> filament connecting the two sunspots exploded on August 5 around
> 0500 UTC, hurling the CME into space.
> 
> An X1.6 class eruption was observed in AR3386 on August 5 at 2221
> UTC. The CME did not head directly toward Earth, so there were fewer
> disturbances than expected with the current solar activity. But the
> opposite was true for shortwave propagation conditions - they were
> mostly worse.
> 
> The proton flux higher than 10 MeV began to rise at 2146 UTC on
> August 7 and exceeded the 10 MeV warning threshold at 0110 UTC. This
> proton event followed the X1.5 eruption observed on August 7 with a
> peak at 2046 UTC. Thereafter, the proton flux above 10 MeV started
> to slowly decrease and remained close to the threshold.
> 
> F. K. Janda OK1HH http://ok1hh.nagano.cz/
> 
> In the past, I've noted odd 10 meter propagation observed with
> pskreporter.info using FT8 in which my signals (from Seattle) were
> only received in Florida, about 2300 to 2700 miles away.
> 
> On Thursday, August 10 at 2200 UTC on 12 meters FT8 the only reports
> from North America I saw were in Florida, 2500-2700 miles away, plus
> NH6V in Hawaii, and VK5HW and VK4TUX in Australia at 8367 and 7402
> miles. I have no idea what causes this seemingly restricted
> propagation. The antenna at my end was an end fed 32 foot wire,
> about .85 wavelength, partially indoors.
> 
> Solar mysteries.  https://bit.ly/3qpuhhW
> 
> Flares: https://bit.ly/3KXlUl1 https://bit.ly/3qj0pE6
> 
> https://bit.ly/3QPYPV9 https://bit.ly/45naVsF https://bit.ly/3OQPzhL
> 
> https://bit.ly/3OvB3uz https://bit.ly/47kgZ70
> 
> Tamitha Skov: https://youtu.be/Olfjss8GmSI
> 
> You can always catch the latest video from Dr. Skov on Youtube at:
> 
> https://www.youtube.com/c/TamithaSkov
> 
> This weekend is the Worked All Europe DX Contest:
> 
> https://www.darc.de/der-club/referate/conteste/wae-dx-contest/en/
> 
> Send your tips, reports, observations, questions and comments to
> k7ra at arrl.net. When reporting observations, don't forget to tell us
> which mode you were operating.
> 
> For more information concerning shortwave radio propagation, see
> http://www.arrl.org/propagation and the ARRL Technical Information
> Service at http://arrl.org/propagation-of-rf-signals. For an
> explanation of numbers used in this bulletin, see
> http://arrl.org/the-sun-the-earth-the-ionosphere .
> 
> Also, check this article from September, 2002 QST:
> 
> https://www.arrl.org/files/file/Technology/tis/info/pdf/0209038.pdf
> 
> 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/ .
> 
> Instructions for starting or ending email distribution of ARRL
> bulletins are at http://arrl.org/bulletins.
> 
> Sunspot numbers for August 3 through 9, 2023 were 124, 122, 100, 97,
> 101, 115, and 103, with a mean of 108.9. 10.7 cm flux was 162.9,
> 170.8, 175.8, 173.5, 169.7, 158.9, and 153.4, with a mean of 166.4.
> Estimated planetary A indices were 6, 13, 36, 4, 12, 8, and 7, with
> a mean of 12.3.  Middle latitude A index was 5, 12, 24, 4, 11, 7,
> and 8, with a mean of 10.1.
> NNNN
> /EX