ARLP006 Propagation de K7RA
ZCZC AP06
QST de W1AW
Propagation Forecast Bulletin 6 ARLP006
From Tad Cook, K7RA
Seattle, WA February 11, 2022
To all radio amateurs
SB PROP ARL ARLP006
ARLP006 Propagation de K7RA
Three new sunspot groups appeared this week, on February 3, 6 and 8.
Average daily sunspot number rose slightly from 81.3 last week to
83.9 in this reporting week, February 3-9.
Average daily solar flux increased from 123.1 to 126, also a modest
change.
Solar flares and geomagnetic storms through the week raised the
average daily planetary A index from 10.1 to 14.4, and the middle
latitude A index, measured at one location in Virginia, went from
6.4 to 9.6.
At 0523 UTC on February 11 the Australian Space Forecast Centre
issued a Geomagnetic Disturbance Warning: "A recurrent coronal hole
is expected to cause unsettled to active conditions with possible
minor storm periods on 12 to 13 February."
A geomagnetic storm on February 4 brought down 40 of the low earth
orbit Starlink satellites, even though the storm was not especially
robust. But from February 3-4, the high latitude college A index
measured near Fairbanks, Alaska was 48 and 61, respectively, a level
that assures the appearance of aurora borealis.
NN4X sent this on the LEO satellites loss:
https://bit.ly/3GCIQkd
Normally we think of geo-storms as a negative event regarding HF
propagation, but not always, as sometimes there is propagation via
bouncing signals off the aurora.
K7SS commented at 2030 UTC on February 10 in an email posting
titled, "EU aurora on 10 meter CW.
"Weak OH, SM, UA, opening now. All aurora sounding. Point 'em North
boys."
"All aurora sounding" refers to the unusual garbled fluttery sounds
of auroral propagation, and then advice to point your antenna north
to propagate signals via the aurora.
W7YED responded:
"Yeah, I saw 2 SM3s at around 2100 UTC calling CQ on 10m FT8. One
worked an XE, lasted about 5 minutes then went away. And now back to
the regularly scheduled Caribbean and SA stations. Things are
looking up on 10!"
So far in the year 2022 sunspots were visible on every day. Last
year 64 days had no sunspots, and in 2020, 208 days were spotless,
according to spaceweather.com.
Predicted solar flux values for the near term are 118 and 116 on
February 11-12, 112 on February 13-14, 110 on February 15-16, 112 on
February 17, 115 on February 18-19, 118 on February 20, 120 on
February 21-23, 125 on February 24-25, 120 on February 26 through
March 4, then 115 and 122 on March 5-6, 120 on March 7-9, 110 on
March 10-11, 115 on March 12-18, 118 on March 19, and 120 on March
20-22.
Predicted planetary A index is 20, 12, 22 and 25 on February 11-14,
then 20, 12, 8, 10 and 8 on February 15-19, then 5, 10, 8, 5, 8 and
12 on February 20-25, then 8 on February 26-27, 5 on February 28 to
March 2, then 12, 10, 15 and 10 on March 3-6, 5 on March 7-11, then
25 and 20 on March 12-13, 5 on March 14-15, then 10, 12 and 8 on
March 16-18.
From F.K. Janda, OK1HH:
"I would like to return once again to the solar flare M1 in AR2936
on January 29, accompanied by LDE (long-running event) see:
https://www.swpc.noaa.gov/content/space-weather-glossary, which
caused the halo CME. The CME was met near Earth by 49 Starlink
satellites launched into low Earth orbit from the Kennedy Space
Center in Florida on February 3.
"As a result, 40 of them did not get into the planned orbit and then
burned in the atmosphere in a controlled manner. The cost to launch
the Falcon 9 is $30 million dollars, one satellite is half a million
dollars, total damage to Elon Musk costs $50 million dollars.
"Solar activity in Solar Cycle 25 is rising faster than most models
expected. More accurate predictions of further developments are
complicated by the fact that there are several irregularly evolving
active areas on the Sun at the same time. For this reason, too, we
cannot rely on the twenty-seven-day periodicity, which is otherwise
a good tool for compiling forecasts.
"If we take advantage of it, we can expect the next major
disturbance on 13-14 February. The beginning of calm can be expected
since February 16 and quiet days since February 19. Solar flux
should not fall below 100 or rise too high above 130."
Dr. Tamitha Skov, WX6SWW, with a great update, all 93 minutes:
https://youtu.be/uY3TMaExHkg
N8II reported from West Virginia on February 7:
"I was active in the VT, MN, and BC QSO Parties this past weekend.
Conditions were excellent to MN on 20M with loud signals from 1500
UTC until about 2230 UTC (our sunset was 2237 UTC). Even the mobiles
were very good copy, many quite loud on 20M. 40M suffered from D/E
layer absorption with almost all MN signals below my noise level
from 1700-2030 UTC. 80M was open well before MN sunset with workable
signals at 2300 UTC and some very good signals by 2330 UTC.
"15 and even 10 M were open to British Columbia both weekend days.
The peak of 10M propagation was in the 1900 UTC hour both days with
Saturday being better on both 20 and 15M. Several BC 10M signals
were over S9 on Saturday. There were many USA Rocky Mountain area
and west coast signals on the band as well. 20M conditions were
excellent Saturday from 1600-2400 UTC. 15/10 were slow to open
Sunday finally opening around 1830 UTC.
"Propagation to VT was about as expected, some loud signals
0000-0030 UTC on 40M, VT stations on 75/80M were mostly loud. 160M
signals were fairly weak Friday PM. There was no miracle Es opening
like last year, 20M was open on backscatter only and W1JXN was
worked on 15M CW backscatter just above the noise.
"Sunday morning, the 6th there was a good opening to southern Europe
on 10M. I had a SSB run from 1515-1550 UTC working Croatia,
Switzerland, Spain, and many French and Italian stations. Many
signals were over S9. 12M in the past few days has been open to at
least southern EU daily.
"Last Friday, February 4, 10M was wide open to New Caledonia from
2130-2245 UTC. I easily logged FK8IK on both CW and SSB, and FK4QX
on SSB. This followed loud signals from the western USA."
Images of recent sunspot regions:
http://www.hkastroforum.net/viewtopic.php?f=28&p=321591
Study offers explanation for unusual motions in solar flares, oddly
referred to as "Solar Flames":
https://bit.ly/3uHX5SI
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 3 through 9, 2022 were 84, 87, 91, 83,
78, 86, and 78, with a mean of 83.9. 10.7 cm flux was 126.5, 129.6,
125.9, 123.6, 127.2, 123.1, and 125.9, with a mean of 126. Estimated
planetary A indices were 27, 32, 12, 15, 7, 5, and 3, with a mean of
14.4. Middle latitude A index was 18, 18, 10, 12, 4, 3, and 2, with
a mean of 9.6.
NNNN
/EX
