SB PROP @ ARL $ARLP007
ARLP007 Propagation de K7RA
ZCZC AP07
QST de W1AW
Propagation Forecast Bulletin 7 ARLP007
From Tad Cook, K7RA
Seattle, WA February 18, 2022
To all radio amateurs
SB PROP ARL ARLP007
ARLP007 Propagation de K7RA
Although solar activity was generally lower this week, new sunspots
appeared. A sunspot group emerged on February 10, two more on
February 11, two more on February 14 and three more on February 16,
when the daily sunspot number rose to 111, the highest value for
this reporting week and well above the weekly average, which was
75.3. The average for the previous week was 83.9. On February 17
another new sunspot region emerged, but the daily sunspot number
declined from 111 to 103.
The 111 sunspot number was the highest since the end of 2021, when
sunspot numbers went as high as 147 following a few days of no
sunspots at all.
On Thursday night (February 17) the Daily Sun image on
Spaceweather.com showed seven sunspot groups, the whole Earth facing
side of the Sun peppered with spots.
Average daily solar flux declined from 126 to 110.1. Average daily
planetary A index went from 14.4 to 13, and average daily middle
latitude A index declined just 1.3 points to 8.3.
Why do we care about sunspot numbers? Because high values correlate
with greater density in the ionosphere, which gives us better
propagation at higher frequencies. 64 years ago, sunspot numbers
were so high that hams saw worldwide around the clock propagation on
the 10 meter band. Sunspot numbers were never so high before or
since. That was the peak of Solar Cycle 19. Newly licensed hams
thought it would always be like that. It never was.
Predicted solar flux over the next month was downgraded from
February 16-17 forecasts, and is 95 on February 18-19, 98 on
February 20, 102 on February 21-23, 105 on February 24, 108 on
February 25-27, 110 on February 28, 115 on March 1-2, 112 and 110 on
March 3-4, 108 on March 5-8, 105 on March 9-11, 103 on March 12-13,
100 on March 14, 98 on March 15-16, 102 on March 17-19, 104 on March
20-22, 108 on March 23-26 and 110 on March 27.
Predicted planetary A index is 5 on February 18-19, then 18, 15 and
12 on February 20-22, then 10, 8 and 10 on February 23-25, 15 and 10
on February 24-25, 5 on February 26 to March 2, then 12, 15, 10 and
8 on March 3-6, 5 on March 7-10, then 15, 12 and 10 on March 11-13,
5 on March 14-18, then 8, 5, 12, 15, 18 and 10 on March 19-24, and 5
on March 25-29.
Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere, February 10, 2022, from OK1HH:
"Solar activity has reached a moderate level, including occurrence
of M-class flares. The activity on the far side of the Sun was
greater, as evidenced by CME observations beyond the eastern limb of
the solar disk, which do not affect the Earth's ionosphere.
"We observed exceptionally bad conditions of ionospheric propagation
in the bands of 80 meters and especially 160 meters on the night of
February 14-15, UTC. The cause was a several-day decrease in solar
radiation (X-ray level), accompanied by a decrease in the speed of
the solar wind, as a source of ionization by particles. The
improvement started in the morning of February 15, beginning from
the eastern direction when the ionosphere was irradiated by the Sun
again.
"Solar activity is expected to rise only slowly in the coming days,
reaching a flat quasi-peak maximum in early March. The activity of
the Earth's magnetic field should increase irregularly and only
slightly again on 20-21 and 24-25 February (according to other
sources on February 22-24), causing only the usual fluctuations in
the level of propagation conditions."
NN4X reported on February 16:
"I was a little late to the party on 10m, having started checking
propagation on 12m first.
"Conditions were excellent this morning, easily the best 10m Long
Path opening I've ever seen.
"I was fortunate to have FT8 QSOs with these stations this morning:
"BF7IEJ (1304 UTC)
YC9AUB (1306 UTC)
YC1THS (1319 UTC)
YC7UDD (1346 UTC)
VK3EW (1419 UTC)
JK1OZS (1344 UTC)
VR2CH (1307 UTC)
VR2XYL (1305 UTC)
VR2VAZ (1339 UTC)
"I also worked VR2CH on 10m LP on Tuesday, 02/15/2022. Great fun!
"I wanted to pass this along because I found it so interesting.
While monitoring 12m FT8 around 1905 UTC this afternoon, with the
antenna pointed 90 degrees, looking for African stations, I noticed
YB0DJ decode.
"I proceeded to work him, and he was gone shortly thereafter. I've
never seen a long path opening so far away from sunrise to sunset.
Using PSKR, we can see at least some of the extent of that opening
(note that the daylight/nighttime shading is for the time I ran the
search).
"From K7RA, he sent an image of the map, which I have no way of
presenting here.
"YB0DJ 2/16/2022 1905 UTC 24.915 MHz"
N0JK reported on February 17:
"A sporadic-E opening occurred on February 13 UTC.
"I logged W4IMD (EM84) on 50.313 MHz at 0141 UTC. The only Es
station worked on 6 Meters. Then on 17 Meters worked KC5LT (EM86) at
0228 UTC on FT8 on Es. Sporadic-E openings are rare in the month of
February. 73, Jon, N0JK, EM28, Kansas."
Check out this video about a ViewProp, a promising new propagation
analysis tool: https://youtu.be/McUB2eY5atk .
There is also an email list for it: https://groups.io/g/viewprop .
Thanks to ARRL Contest Update for the information.
A reader named Neil J. shared this:
https://sdo.gsfc.nasa.gov/data/aiahmi/
A new robotic system at Sunspot, New Mexico observatory:
https://bit.ly/33v3x4i
This weekend is the CW portion of the ARRL International DX Contest.
Details can be found here:
http://www.arrl.org/arrl-dx
If you would like to make a comment or have a tip for our readers,
please email the author at, k7ra@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 February 10 through 16, 2022 were 78, 86, 54,
53, 72, 73, and 111, with a mean of 75.3. 10.7 cm flux was 118,
113.1, 110.5, 105.4, 106.5, 114.3, and 102.9, with a mean of 110.1.
Estimated planetary A indices were 21, 20, 13, 15, 8, 5, and 9, with
a mean of 13. Middle latitude A index was 12, 12, 10, 9, 6, 3, and
6, with a mean of 8.3.
NNNN
/EX
