[SFDXA] ARLP051 Propagation de K7RA

[Bill]

> SB PROP @ ARL $ARLP051
> ARLP051 Propagation de K7RA
> 
> ZCZC AP51
> QST de W1AW  
> Propagation Forecast Bulletin 51  ARLP051
> From Tad Cook, K7RA
> Seattle, WA  December 17, 2021
> To all radio amateurs 
> 
> SB PROP ARL ARLP051
> ARLP051 Propagation de K7RA
> 
> Sunspots disappeared over four days, December 8-11. Average daily
> sunspot numbers and solar flux hardly changed at all, with sunspots
> at 24.4 during the current reporting week (December 9-15) compared
> to 24.6 last week, and average daily solar flux shifting from 82.6
> to 82.9.
> 
> By Wednesday solar flux rose to 102.5. But sunspots have come back
> dramatically over the past few days, with the daily sunspot number
> hitting 127 on Thursday, December 16. On that same day, the noon
> 10.7 cm solar flux reading at the Penticton observatory was 117.9
> and it reached 121.5 at the 2200 UTC reading.
> 
> Geomagnetic activity was quiet. Average daily planetary A index
> changed from 7.6 to 5, and average daily middle latitude A index
> from 5.3 to 3.9.
> 
> One new sunspot group emerged on December 12, then two the following
> day, two more on December 15 and another two on December 16.
> 
> Predicted solar flux over the next month looks very good for this
> week, at 118 on December 17-21, 115 and 110 on December 22-23, 82 on
> December 24-27, 80 on December 28, 78 on December 29, 2021 through
> January 3, 2022, then 80 on January 4-10, 82 on January 11, and 84
> on January 12-17. The predicted flux values then drop below 80 after
> January 24.
> 
> Predicted planetary A index is 8 on December 17, 5 on December
> 18-19, then 8, 16, 12 and 8 on December 20-23, 5 on December 24-26,
> then 15, 18 and 12 on December 27-29, 8 on December 30, 2021 through
> January 1, 2022, 5 on January 2-8, then 8 and 5 on January 9-10,
> then 12, 10, 10, and 8 on January 11-14, 5 on January 15-22, then
> 15, 18 and 12 on January 23-25, and 8 on January 26-28.
> 
> Unfortunately, propagation was poor last weekend during the annual
> ARRL 10 Meter Contest, not surprising with no sunspots on the two
> days prior to the contest and non through the weekend. On Friday
> night I heard no signals (with a modest dipole antenna), so I called
> CQ using CW just above 28 MHz, and worked one local station, only 8
> miles away. I worked a few stations on Sunday across North America,
> and heard many TEP signals from South America.
> 
> Don't miss "Understanding an Ionosonde to Understand the Ionosphere"
> by propagation expert KL7AJ in January 2022 QST, currently available
> online.
> 
> Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
> Ionosphere - December 16, 2021 from F.K. Janda, OK1HH.
> 
> "Solar activity has risen a little more and faster in recent days
> than we expected. After several smaller eruptions, the probability
> of an M-class solar flare increased. Although Solar Cycle 25 is
> still closer to the minimum, we can expect its maximum in 3 to 4
> years to be higher than usually predicted. The last rise in solar
> activity is not long (in recent days only), after that a decline can
> be expected again in the last week of December.
> 
> "Although most of the active areas are located south of the solar
> equator and not too far from the coronal holes, we still expect only
> a slight increase in geomagnetic activity at the beginning of the
> third week of December.
> 
> "The Earth's ionosphere reacted significantly to the last rise of
> solar radiation by the rise of MUF. However, the hitherto stable
> development will be replaced by fluctuations and deformations of the
> daily course - which will happen immediately, probably at the
> beginning of the third week of December. This will be followed by a
> relatively significant decrease in MUF, both day and night. The
> decline of MUF by night will be significant if the onset of the
> increase in geomagnetic activity will be up during the night."
> 
> Here is a geomagnetic activity summary from Tomas Bayer, RWC Prague
> Institute of Geophysics of the ASCR, Prague Department of
> Geomagnetism, Budkov observatory, preceded by a geomagnetic activity
> forecast for the period December 17-23, 2021:
> 
> "Quiet: December 17-18, 22-23
> Unsettled: December 18-22
> Active: December 18-19
> Minor storm: unlikely about December 19
> Major storm: 0
> Severe storm: 0
> 
> "We expect geomagnetic activity enhancement about December 18-19. We
> expect an unsettled to active episode, storming defect is less
> probable.  Till this event, and also at the end of current forecast
> period, we expect at most quiet to unsettled conditions."
> 
> Max White, M0VNG sent this from the European Space Agency:
> 
> https://bit.ly/3IQBLix
> 
> Dr. Tamitha Skov, WX6SWW has more of her continuing space weather
> course:
> 
> https://youtu.be/T8di-D1s-40
> 
> I received many emails correcting the info I gave last week on the
> Fred Fish Memorial Award.  This sums it up best:
> 
> https://www.arrl.org/ffma
> 
> If you would like to make a comment or have a tip for our readers,
> please email the author at, k7ra at arrl.net .
> 
> For more information concerning shortwave radio propagation, see
> http://www.arrl.org/propagation and the ARRL Technical Information
> Service web page 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.
> 
> 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 December 9 through 15, 2021 were 0, 0, 0, 12,
> 40, 40, and 79, with a mean of 24.4. 10.7 cm flux was 76.7, 75.7,
> 76.2, 79.9, 80.6, 88.9, and 102.5, with a mean of 82.9. Estimated
> planetary A indices were 3, 4, 5, 3, 6, 5, and 9, with a mean of 5.
> Middle latitude A index was 2, 2, 3, 2, 6, 4, and 8, with a mean of
> 3.9.
> NNNN
> /EX