[SFDXA] ARLP025 Propagation de K7RA

[Bill]

> SB PROP @ ARL $ARLP025
> ARLP025 Propagation de K7RA
> 
> ZCZC AP25
> QST de W1AW  
> Propagation Forecast Bulletin 25  ARLP025
> From Tad Cook, K7RA
> Seattle, WA  June 23, 2023
> To all radio amateurs 
> 
> SB PROP ARL ARLP025
> ARLP025 Propagation de K7RA
> 
> Sunspot numbers and solar flux rose this week. There were two new
> sunspot groups on June 15, another on June 17 and one more on June
> 18, three more on June 19, two more on June 20 and another on June
> 21.
> 
> Average daily sunspot number increased from 122 to 143, and average
> daily solar flux rose from 154.8 to 165.4.
> 
> Average daily planetary A index jumped from 5.7 to 15.4, while the
> middle latitude numbers increased from 6.7 to 13.1.
> 
> Predicted solar flux is 180 on June 23-24, 185 on June 25-27, 180 on
> June 28, 175 on June 29 through July 1, 180 on July 2-3, 175 on July
> 4-5, 170 on July 6-10, then 165 on July 11, 160 on July 12-13, 165
> on July 14-15, 160 and 155 on July 16-17, 160 on July 18-19, 165 on
> July 20-24, 170 on July 25, 175 on July 26-28, and 180 on July
> 29-30.
> 
> Predicted planetary A index is 14, 10 and 8 on June 23-25, then 5,
> 5, and 12 on June 26-28, then 5, 5, and 12 again on June 29 through
> July 1, 8 on July 2, 5 on July 3-7, 12 on July 8, 5 on July 9-11,
> then a dramatic increase to 20 and 30 on July 12-13, 8 on July
> 14-15, and 12 on July 16-17, 10 on July 18, 5 on July 19-23, 12 on
> July 24-25, 5 on July 26-27, 12 and 8 on July 28-29, and 5 on July
> 30 through August 3.
> 
> These predictions are from forecasters Liming and Dethlefsen of the
> US Air Force 557th Weather Wing at Offutt AFB.
> 
> See https://bit.ly/3qRNJnr
> 
> So, what does this forecast show for ARRL Field Day, which is this
> weekend?
> 
> Geomagnetic numbers are a bit more unsettled than what was shown in
> last week's bulletin, which had an A index of 5 for Friday through
> Sunday. The latest shows 14, 10 and 8. Predicted solar flux looks
> excellent, at 180, 180 and 185.
> 
> Of course, Field Day does not begin until Saturday, but here we also
> include data for the day prior.
> 
> X1.1 solar flare:
> 
> https://bit.ly/3CI0OCA
> 
> Another report from South Asia regarding solar flares as some sort
> of existential threat.  Don't worry. Nothing terrifying about what
> they report, but there is a nice description of what the SOHO
> observatory does.
> 
> https://bit.ly/444VhSk
> 
> https://soho.nascom.nasa.gov
> 
> Reader David Moore shared this video:
> 
> https://www.space.com/earth-sunlight-dance-solstice-video
> 
> Don't know why, but no weekly report from OK1HH this time around.
> 
> On Thursday I attended an online event, the "Space Weather
> Enterprise Forum," thanks to a tip from K6PFA.
> 
> Most of the sessions concerned threats from solar flares, but there
> was great commentary from Bill Murtaugh of NOAA's Space Weather
> Prediction Center.
> 
> He noted that the current solar cycle should peak in summer 2024
> instead of 2025 and will peak much stronger than the consensus
> forecast from earlier in the cycle. He also noted that increased
> flare activity always occurs in the years following a sunspot cycle
> peak.
> 
> John Dudley, Managing Director of Flight Operations at American
> Airlines gave an interesting presentation about how space weather
> affects routing of international flights.
> 
> He mentioned their expert on space weather at the airline, and I
> looked him up. Yes, a ham, KC1ENP. Could not find an email address
> for him, so I sent a QSL card to make contact.
> 
> Thanks to https://spaceweather.com/ for this fascinating article about
> setting up a personal space weather station.  It is under the
> heading, "A New Way To Detect Solar Flares":
> 
> https://essd.copernicus.org/articles/15/1403/2023/
> 
> 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 June 15 through 21, 2023 were 112, 120, 110,
> 133, 181, 155, and 190, with a mean of 143. 10.7 cm flux was 153.1,
> 157.2, 158.1, 164.1, 168.8, 180.1, and 176.4, with a mean of 165.4.
> Estimated planetary A indices were 24, 38, 8, 10, 10, 10, and 8,
> with a mean of 15.4. Middle latitude A index was 17, 24, 8, 12, 9,
> 13, and 9, with a mean of 13.1.
> NNNN
> /EX