[SFDXA] ARLP050 Propagation de K7RA

Fri Dec 15 16:33:01 EST 2023

> SB PROP @ ARL $ARLP050
>> ARLP050 Propagation de K7RA
>> 
>> ZCZC AP50
>> QST de W1AW  
>> Propagation Forecast Bulletin 50  ARLP050
>> From Tad Cook, K7RA
>> Seattle, WA  December 15, 2023
>> To all radio amateurs
>> 
>> SB PROP ARL ARLP050
>> ARLP050 Propagation de K7RA
>> 
>> "GEOMAGNETIC DISTURBANCE WARNING ISSUED AT 0132 UTC ON 15 DECEMBER
>> 2023 BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE.
>> 
>> "Two predominately westward CMEs were observed on 14-Dec and
>> component arrivals are expected on 17-Dec.
>> 
>> "INCREASED GEOMAGNETIC ACTIVITY EXPECTED FOR 17 DECEMBER 2023."
>> 
>> Spaceweather.com issued this alert on Thursday:
>> 
>> "MAJOR X-CLASS SOLAR FLARE: The Sun just unleashed the strongest
>> solar flare of Solar Cycle 25 (so far), an X2.8-class explosion from
>> unstable sunspot AR3514. The blast caused a deep shortwave radio
>> blackout over the Americas and may have hurled a fast CME toward
>> Earth."
>> 
>> Solar activity declined this week. Average daily sunspot numbers
>> dropped from 121.1 to 110.3, and average daily solar flux from 146.5
>> to 129.8.
>> 
>> With such low geomagnetic activity, conditions were good for last
>> weekend's ARRL 10 Meter Contest, although some wished for more
>> sunspots.
>> 
>> Six new sunspot groups appeared this week. The first two on December
>> 8, another two on December 11 and 12, and two more on December 13.
>> 
>> Geomagnetic conditions were quieter, with planetary A index dropping
>> from 14.1 to 5.6, and middle latitude numbers from 7.3 to 4.6.
>> 
>> Predicted solar flux shows some expected improvement, with values
>> peaking at 160 on December 20-22, and 155 on January 23.
>> 
>> Predicted solar flux is 135 on December 15-16, then 145, 150 and 155
>> on December 17-19, 160 on December 20-22, but dropping back to 140
>> on December 23-24, 150 on December 25-26, then 155, 150 and 145 on
>> December 27-29, then 140 on December 30 through January 2, 2024, and
>> 135 on January 3-5, then 130, 125, 120, 118, and 120 on January
>> 6-10, 122 on January 11-12, then 124, 125, and 130 on January 13-15,
>> 135 on January 16-18, 140 on January 19-20, and 150 on January
>> 21-22.
>> 
>> Predicted planetary A index is 18 and 22 on December 15-16, 12 on
>> December 17-18, then 18, 8, 8, 20 and 10 on December 19-23, 5 on
>> December 24-29, 8 on December 30-31, then 10 and 8 on January 1-2,
>> 2024, 5 on January 3-6, 12 on January 7-9, 8 and 5 on January 10-11,
>> 12 on January 12-13, then 15, 25, 8, 5, 20 and 10 on January 14-19,
>> and 5 for at least the following few days.
>> 
>> "Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
>> Ionosphere December 15-21, 2023 from F.K. Janda, OK1HH:
>> 
>> "Solar activity has been gradually decreasing over the last seven
>> days, broadly in line with the forecast.
>> 
>> "Most of the flares came from the active region AR3514, which was
>> moving from the northeast to the northwest.
>> 
>> "Eventually, most of the sunspots were in the northwest of the solar
>> disk, and as they gradually set over the next few days, solar
>> activity should continue to decrease.
>> 
>> "While activity on the Sun's receding half does not appear to be
>> great, there is definitely a larger active region beyond the Sun's
>> northeastern limb. This observation is likely the basis for the
>> latest forecast from the U.S. Air Force, which predicts a rise in
>> solar flux initially to 160, and after a slight drop back above 150
>> around Christmas.
>> 
>> "Shortwave propagation conditions, which have suffered particularly
>> in the Earth's northern hemisphere from the decline in solar
>> activity, should improve.
>> 
>> "But developments may be more complicated. Just as a CME originating
>> from the solar flare of 11 December with a peak at 2243 UT arrived
>> at Earth before midnight UTC on 13 December, triggered a geomagnetic
>> disturbance in the first hours UTC on 14 December and significantly
>> worsened propagation, we can expect something similar from the
>> stronger flare of 14 December with a peak at 0744 UTC. However,
>> subsequent geomagnetic disturbances should be no more intense than
>> G1."
>> 
>> Reader David Moore sent this article from "SpaceNews":
>> 
>> https://bit.ly/46ZKDNF
>> 
>> On Wednesday morning Spaceweather.com announced:
>> 
>> "The best meteor shower of the year is expected to peak on December
>> 13-14 with no Moon to spoil the show. Rural observers could see
>> hundreds of Geminid meteors and more than a few fireballs."
>> 
>> From Angel Santana, WP3GW in Trujillo Alto, Puerto Rico:
>> 
>> "The 10 meter contest in my view was pretty nice on average,
>> although did notice this:
>> 
>> "During 0000 UTC on Saturday got always South America for about 3
>> hours before the band closed. Then before 1200 UTC got to work
>> VR2XAN which was a surprise as my antenna was pointing to Europe (he
>> said he was beaming the South Pole) and it's been 10 years since I
>> worked Hong Kong for the first time.
>> 
>> "But then, could not work a few Europeans, and the band likely
>> closed to them by 1500 UTC, and the US was pretty strong.
>> 
>> "Then it closed at 2230 UTC, so SA predominated again. It repeated
>> for Sunday.
>> 
>> "Also noted that there was a lot of fading as some stations
>> disappeared for a few seconds to a minute. And the SFI dropped to
>> 130 which could have been a factor.
>> 
>> "But for what I am happy is that I accumulated 600 points for the
>> VOTA event, and I delivered 35."
>> 
>> Did you know India has a solar observatory in space?  Here is an
>> article from "The Times Of India":
>> 
>> https://bit.ly/3GGecsH
>> 
>> From WBZ news, a story about a Massive Solar Flare:
>> 
>> https://bit.ly/4anifba
>> 
>> Bil Paul, KD6JUI wrote:
>> 
>> "The solar flux wasn't optimal for the ARRL 10-meter contest last
>> weekend, but it was good enough. There was a lot of activity on the
>> voice part of the band.
>> 
>> "Operating from my kayak with 10 watts and a small homebrew loop, I
>> gathered 38 contest exchanges on Saturday and Sunday, around 3-1/2
>> hours of operating in total.
>> 
>> "On Saturday, South and Central America, and Caribbean stations were
>> coming in as well as the usual Canadian stations for
>> out-of-the-country exchanges. I managed to snap up one Brazilian
>> station for DX.
>> 
>> "On Sunday, I heard Australian stations coming in, but couldn't get
>> them to hear me. There were also more Brazilian stations plus a few
>> from Argentina.
>> 
>> "I was operating around noontime. QSB was evident."
>> 
>> Dr. Tamitha Skov, WX6SWW, put out a new video this week:
>> 
>> https://youtu.be/64CTIrWBGTc
>> 
>> A couple of interesting QRZ.com pages to check out: KS7ROH for his
>> astrophotography and other projects, and W6BSD for links to his
>> propagation pages.
>> 
>> 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.
>> 
>> 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/ .
>> 
>> Also, check this article from September, 2002 QST:
>> 
>> https://bit.ly/3Rc8Njt
>> 
>> Instructions for starting or ending email distribution of ARRL
>> bulletins are at http://arrl.org/bulletins .
>> 
>> Sunspot numbers for December 7 through 13, 2023 were 121, 125, 125,
>> 120, 87, 80, and 114, with a mean of 110.3. 10.7 cm flux was 134.6,
>> 132.6, 127.9, 126.6, 125.9, 126.2, and 134.8, with a mean of 129.8.
>> Estimated planetary A indices were 5, 5, 3, 4, 3, 10, and 8, with a
>> mean of 5.6. Middle latitude A index was 4, 4, 2, 4, 3, 8, and 7,
>> with a mean of 4.6.
>> NNNN
>> /EX