[SFDXA] ARLP035 Propagation de K7RA

[Bill]

> SB PROP @ ARL $ARLP035
> ARLP035 Propagation de K7RA
> 
> ZCZC AP35
> QST de W1AW  
> Propagation Forecast Bulletin 35  ARLP035
> From Tad Cook, K7RA
> Seattle, WA  September 1, 2023
> To all radio amateurs 
> 
> SB PROP ARL ARLP035
> ARLP035 Propagation de K7RA
> 
> First, this alert from Australia.
> 
> "ASWFC GEOMAGNETIC DISTURBANCE WARNING ISSUED AT 0706UTC/31 AUGUST
> 2023 BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE.
> 
> A filament eruption and associated coronal mass ejection (CME) were
> observed on UT day 30-Aug. This CME is expected to impact Earth from
> 1800 UT +/- 12 hours on 02-Sep, with impacts possibly rolling into
> UT day 03-Sep. G1-G2 geomagnetic conditions are expected over this
> time, with a chance for periods of G3."
> 
> Solar activity was down again this week, with average daily sunspot
> numbers dropping from 105.9 to 78.7, and average daily solar flux
> from 149.4 to 140.9.
> 
> Only three sunspot groups appeared, one each on August 25, 28 and
> 30.
> 
> But I have noticed a gradual transition from summer toward fall
> conditions, with 10 and 12 meter openings more frequent. The
> autumnal equinox is only three weeks from now.
> 
> Geomagnetic indicators were a little lower. Average planetary A
> index went from 8.4 to 7, and average middle latitude numbers from
> 10.1 to 8.9.
> 
> What is the outlook?
> 
> Predicted solar flux shows a peak around 168 on September 18-21.
> 
> Forecast values are 140 on September 1, then 150, 150 and 145 on
> September 2-4, 150 on September 5-9, 147 on September 10-11, then
> 145, 150, 155, 150, 155 and 160 on September 12-17, 168 on September
> 18-21, then 165, 160, and 148 on September 22-24, 150 on September
> 25-26, then 152, 150, 145,and 140 on September 27-30, then 145 on
> October 1, 150 on October 2-3, 152 on October 4, 156 on October 5-6,
> 150 on October 7. and 148 on October 8-9.
> 
> Predicted planetary A index is 10, 12 and 35 on September 1-3, then
> 15, 10 and 8 on September 4-6, 5 on September 7-13, then 12, 10, 10
> and 8 on September 14-17, 5 on September 18-22, then 10, 10 and 8 on
> September 23-25, 5 on September 26 to October 2, then 10, 8 and 8 on
> October 3-5, and 5 on October 6-10.
> 
> Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
> Ionosphere for September 1-7, 2023 from OK1HH.
> 
> "On 27 August, we predicted a rise in geomagnetic activity,
> triggered by the arrival of particles from the filament solar flares
> three days earlier. It did occur, but to a lesser extent than we
> expected. No significant solar flare (at least of M-class) was
> observed until 25 August, which is somewhat surprising for the
> current phase of Cycle 25 development.
> 
> We did not see a major flare until August 26 at 2250 UTC, and it was
> an M1-class solar flare, hidden behind the Sun's eastern edge, but
> it was a long duration eruption (LDE). It was accompanied by a CME,
> which of course was not heading toward Earth, but in this case Mars
> (which it should hit on September 1).
> 
> The coronal mass ejection (CME) was observed on August 29 at about
> 1748 UTC near the coordinates N05W35. Another major solar flare, C3,
> was observed on August 30 with a maximum at 2334 UTC at AR 3413.
> 
> Prior to that, a filament of solar plasma disappeared near S18W24 at
> 2015 UTC.
> 
> Still, we expect only a slight increase in Earth's magnetic field
> activity in the next few days.
> 
> Ionospheric propagation has varied erratically, with partial credit
> due to the sporadic E layer that occurred irregularly in Earth's
> northern hemisphere late this summer."
> 
> India's solar mission:  https://bit.ly/3PiPJ1N
> 
> Flares:  https://bit.ly/47X6gzC
> 
> Four hours of Tamitha Skov and extreme space weather events:
> 
> https://youtu.be/_Li9wxmmbQs
> 
> This weekend is the phone portion of the All Asia DX Contest: 
> 
> https://bit.ly/43GPrXq 
> 
> 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 24 through 30, 2023 were 86, 77, 75, 69,
> 68, 82, and 94, with a mean of 78.7.  10.7 cm flux was 144.1, 138.9,
> 139.3, 141.5, 141.7, 142.2, and 138.6, with a mean of 140.9.
> Estimated planetary A indices were 9, 5, 7, 11, 6, 5, and 6, with a
> mean of 7. Middle latitude A index was 9, 7, 9, 13, 8, 7, and 9,
> with a mean of 8.9.
> NNNN
> /EX