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ARRL Propagation Bulletin ARLP049 (2022)

SB PROP @ ARL $ARLP049
ARLP049 Propagation de K7RA

ZCZC AP49
QST de W1AW  
Propagation Forecast Bulletin 49  ARLP049
From Tad Cook, K7RA
Seattle, WA  December 9, 2022
To all radio amateurs 

SB PROP ARL ARLP049
ARLP049 Propagation de K7RA

Solar activity bounced back in our reporting week, December 1 to 7.
With solar flux and sunspot numbers dramatically higher and
geomagnetic activity lower, what could be better?  Well, even more
sunspots, I guess.  But this sunspot cycle is already progressing
better than the prediction consensus, so I am grateful.
 
Average daily sunspot numbers increased from 46 to 85, while average
daily solar flux rose from 108.3 to 137.5.
 
How do these numbers compare with a year ago?  The week of December
2 to 8, 2021 had an average daily sunspot number of 24.6 and solar
flux at 82.6.
 
Average daily planetary A index dropped from 18.6 to 14.4, while
middle latitude numbers declined from 14 to 9.1.
 
Predicted solar flux for the next few days is 140 on December 9 to
11, then 130, and 125 on December 12 and 13, 120 on December 14 and
15, 110 on December 16 to 19, 115 on December 20 to 22, 120 on
December 23 to 28, then 125, 130 and 135 on December 29 to 31, then
140 on January 1 to 6, 2023, then 135 on January 8, 125 on January 9
and 10, 115 on January 11, and 110 on January 12 to 15.
 
Predicted planetary A index is 8 on December 9 and 10, 5 on
December 11 to 16, 10 on December 17 and 18, 5 on December 19 to 21,
then 20, 15 and 12 on December 22 to 24, 20 on December 25 to 28,
then 12, 10, 12 and 8 on December 29 through January 1, 2023, then
5, 12, 15 and 8 on January 2 to 5, and 5 on January 6 to 12, then 10
on January 13 and 14, and 5 on January 15 to 17.
  
Don't forget the ARRL 10 meter contest this weekend.
 
https://www.arrl.org/10-meter
 
In North America, that starts on Friday evening, and the latest
prediction shows a promising high solar flux with low geomagnetic
numbers, ideal conditions.
 
F.K Janda, OK1HH wrote:
 
"This week, no dramatic events - no large proton eruptions, and the
fluctuations of the solar wind did not deviate from the limits we
have become accustomed to this year.  The most prominent feature was
the canyon-shaped coronal hole, which paraded from the eastern to
the western half of the solar disk.
 
But its surroundings were changing, especially at its northern end.
From there, the HSS (high-speed solar wind) probably began to flow
from there on December 7th, reaching Earth and finally triggering a
geomagnetic disturbance on the afternoon of the same day.
 
Before the aforementioned coronal hole sinks behind the western edge
of the solar disk in a few days, we can still expect an increase in
the activity of the Earth's magnetic field and irregular changes in
the ionosphere.
 
Don't expect more accurate predictions.
 
A decrease in solar activity will follow, and the decrease in solar
radiation will add up in the ionosphere to the shortening of the
day.  Only with a delay of several days will propagation improve in
the longer part of the short wave band."
 
Mike Schaffer, KA3JAW wrote:
 
"On Wednesday, December 7, 2022, between 1429 and 1432 UTC I
received the United Kingdom, G9PUC in grid square JO00au calling CQ
using digital mode FT8 on the experimental 8-meter (40 MHz) band via
F2 propagation.  Distance was 3541 miles, with an azimuth of 050
degrees.
 
The 8-meter experimental band is within the worldwide
Industrial-Scientific-Medical (ISM) segment between 40.66-40.7 MHz
with a 40 kHz bandwidth, center frequency on 40.680.  Licensed users
are the Fixed, Mobile and Earth exploration- satellite service.
 
G9PUV resides in Iford, England and has an Innovation  Trial
license from Ofcom to conduct research on 8 meters for 12 months,
starting April 1, 2022.
 
Paul uses an Icom IC-706 rig into a W4KMA Log Periodic antenna
(custom 18-100 MHz) at 49 feet AGL at 30 watts.
 
The noon 10.7cm Radio Flux was 148 sfu.  The Estimated Planetary K
index (3 hour data) 12-15 UTC ramped up to a Kp index of 5.
 
I was using the JTDX v2.2.149-32A suite.  The Band Activity window
displayed the following eight decodes.
 
142915 -14  0.3  526 CQ G9PUV JO00 
142945  -5  0.3  526 CQ G9PUV JO00 
143015  -4  0.3  526 CQ G9PUV JO00 
143045 -10  0.3  526 CQ G9PUV JO00 
143115  -6  0.3  525 CQ G9PUV JO00 
143145  -9  0.3  525 CQ G9PUV JO00 
143215 -16  0.3  524 CQ G9PUV JO00 
143245 -11  0.3  524 CQ G9PUV JO00 
 
Less than one hour later, I decoded Ireland, EI2IP in grid square
IO52 calling CQ using digital mode FT8 via F2.  He decoded
twenty-two times.
 
Distance was 3151 miles, with an azimuth of 050 degrees.
 
EI2IP resides in Limerick, Ireland.  (EI) radio amateurs are
authorized to transmit on this band without a Test  Trial license
from ComReg.
 
The Band Activity window displayed the following decodes.
 
152300 -14  0.6 1465 CQ EI2IP IO52 
152600 -18  0.4 1465 CQ EI2IP IO52 
152630 -13  0.5 1464 CQ EI2IP IO52 
152700 -19  0.5 1464 CQ EI2IP IO52 
152730 -12  0.5 1464 CQ EI2IP IO52 
152800 -22  0.4 1464 CQ EI2IP IO52 
152830 -14  0.4 1465 CQ EI2IP IO52 
152900 -11  0.5 1465 CQ EI2IP IO52 
152930 -15  0.5 1467 CQ EI2IP IO52 
153000 -21  0.5 1465 CQ EI2IP IO52 
153530 -15  0.5 1465 CQ EI2IP IO52 
153600 -18  0.5 1464 CQ EI2IP IO52 
153630 -20  0.6 1465 CQ EI2IP IO52 
153700 -19  0.6 1465 CQ EI2IP IO52 
153800 -14  0.5 1465 CQ EI2IP IO52 
153830 -13  0.4 1465 CQ EI2IP IO52 
153900 -20  0.6 1465 CQ EI2IP IO52 
153930 -18  0.6 1467 CQ EI2IP IO52 
154000 -16  0.5 1465 CQ EI2IP IO52 
154030 -20  0.5 1465 CQ EI2IP IO52 
154100 -16  0.5 1467 CQ EI2IP IO52 
155700 -20  0.5 1465 CQ EI2IP IO52" 
 
Thanks to Howard, N7SO for this link:
 
https://www.youtube.com/SVAstronomyLectures
 
Solar physics:
 
https://bit.ly/3Ybi38y
 
Dr. Tamitha Skov's tutorial on the ionosphere, 2 years ago:
 
https://youtu.be/zUXBeYHTsUk
 
WX6SWW Current video:
 
https://youtu.be/eAbskTOybvE
 
Newsweek sunspot report:
 
https://bit.ly/3BlnPuS
 
Send your tips, reports, observations, questions and comments to
k7ra@arrl.net.
 
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 .
 
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 1 through 7, 2022 were 49, 66, 68, 93,
89, 123, and 107, with a mean of 85.  10.7 cm flux was 118.7, 124,
133.8, 143,7, 149.8, 144.2, and 148, with a mean of 137.5. Estimated
planetary A indices were 28, 16, 10, 17, 8, 4, and 18, with a mean
of 14.4.  Middle latitude A index was 18, 11, 7, 10, 7, 2, and 9,
with a mean of 9.1.
NNNN
/EX

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