SB PROP @ ARL $ARLP036
ARLP036 Propagation de K7RA

ZCZC AP36
QST de W1AW
Propagation Forecast Bulletin 36 ARLP036

From Tad Cook, K7RA

Seattle, WA September 9, 2022
To all radio amateurs

SB PROP ARL ARLP036
ARLP036 Propagation de K7RA

This week (September 1 to 7) two new sunspot groups emerged on
September 1, two more on September 2, one more on September 5,
another on September 6 another on September 7 and one more on
September 8 when the sunspot number rose to 75, 7 points above the
average for the previous seven days.

But average daily sunspot numbers declined from 74.9 to 68, while
average daily solar flux rose just two points from 123.8 to 125.8.

On Thursday night the sun is peppered with spots, but none are
magnetically complex and solar flux seems listless at 126.6, barely
above the average for the previous seven days.

Geomagnetic indicators were way up, average daily planetary A index
rose from 10.1 to 24.6, while middle-latitude numbers increased from
9.4 to 17.4.

September 4 was the most active day, when planetary A index was 64.
On that day the college A index in Fairbanks, Alaska was 91.

Predicted solar flux is 125 on September 9 to 13, 120 on September
14, 115 on September 15 and 16, then 125, 126 and 120 on September
17 to 19, 125 on September 20 and 21, 115 on September 22 to 24, 120
on September 25 to 28, 118 on September 29 and 30, 115 and 125 on
October 1 and 2, 120 on October 3 and 4, 122 on October 5, 120 on
October 6 and 7, 125 on October 8 to 11, 126 on October 12, 125 on
October 13 and 14, and 126 on October 15.

Predicted planetary A index is 50 on October 1. Otherwise, 8 on
September 9 to 11, 5 on September 12, 20 on September 13 and 14, 15
on September 15, 8 on September 16 and 17, 5 on September 18 to 22,
then 12 and 10 on September 23 and 24, 14 on September 25 to 27, 8
on September 28 and 29, then 22, 50, 25, 16, 12 and 10 on September
30 through October 5, 8 on October 6 to 8, then 5, 12, 15 and 10 on
October 9 to 12, 8 on October 13 and 14, and 5 on October 15 to 19.

OK1HH writes:

"Over the past seven days, a large coronal hole moved from the
central meridian to the western limb of the solar disk. Its
position relatively close to sunspot group AR3089 meant a high
probability of a geomagnetic disturbance in the following days,
since September 4. Its onset as early as 3 September (class G1) was
related to the intensification of the solar wind and the opening of
a rift in the Earth's magnetic field. The solar wind flow from the
large coronal hole finally hit Earth's magnetic field on September 4
and triggered a G2 class geomagnetic storm.

At the same time, two sunspot groups so large that they affected the
Sun's vibrations developed on the far side of the Sun. These were
AR3088, which had last left the Sun a week earlier and was the
source of a large CME heading for Venus on September 5.

On September 7, AR3092 crossed the central meridian and had a really
long tail above the surface of the Sun. It was a filament coming
out of the core of the spot and curling up into the solar
atmosphere. Inside the filament was a long tube of relatively cool,
dark plasma.

Thereafter the Sun was relatively quiet. The solar disk was dotted
by sunspots, but these have a stable magnetic field, so the chance
of flares was low.

Earth's magnetic field was mostly disturbed on the 3rd to the 6th.
Thereafter was unsettled to active on the remaining days. Shortwave propagation was below average, worst at the end of the disturbance
on September 6. An increase in f0F2 occurred at the beginning of
the disturbance on September 4.

Now a few quiet days followed by another disturbance on 13 and 14
September is expected."

I (K7RA) have been seeing more strange 12 meter propagation
recently. Over and over for several days using FT8 as a propagation
test tool with pskreporter.info, I would call CQ and see that only
stations in Florida were receiving my signal. It looks very odd on
the map. Florida does have a very large ham population, but this
just seems so peculiar.

Regarding the recent overloading of the sensors at Penticton, I
noted I had seen this before, but didn't realize how rare it was. I
paged back through the DRAO archives, and unless I missed something,
the last one was in 2015 on June 22 when the 2000 UTC flux reading
was 246.9. The noon solar flux the following day was only 116.1.

Tamitha Skov's report is a week old, but too late for last week's
bulletin: https://youtu.be/zggTNrpa8Pg

Two massive sunspots: https://bit.ly/3RKKrKI

Longtime contributor David Moore sent this: https://bit.ly/3qIDfDL

Big explosion: https://bit.ly/3Ddd2EC

Our angry sun: https://bit.ly/3B5ZKHg

So huge: https://bit.ly/3qlHQLT

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 September 1 through 7, 2022 were 67, 71, 68, 62,
79, 56, and 73, with a mean of 68. 10.7 cm flux was 116.3, 129.8,
123.4, 128.3, 130.2, 126.2, and 126.1, with a mean of 125.8.
Estimated planetary A indices were 9, 8, 25, 64, 32, 20, and 14,
with a mean of 24.6. Middle latitude A index was 9, 10, 23, 33, 21,
14, and 12, with a mean of 17.4.
NNNN
/EX


--- MBSE BBS v1.0.8 (Linux-x86_64)
* Origin: American Radio Relay League (3:633/280.2@fidonet)

SB PROP @ ARL $ARLP036
ARLP036 Propagation de K7RA

ZCZC AP36
QST de W1AW
Propagation Forecast Bulletin 36 ARLP036

From Tad Cook, K7RA

Seattle, WA September 8, 2023
To all radio amateurs

SB PROP ARL ARLP036
ARLP036 Propagation de K7RA

At 0046 UTC on September 8, the Australian Space Weather Forecasting
Centre issued this alert:

"A solar filament erupted from the north east quadrant of the Sun on
07-Sep. Event modeling shows an edge of the associated north east
directed CME may graze the Earth's magnetosphere on 10-Sep.
INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL MASS EJECTION
FOR 10 SEPTEMBER 2023."

Eight new sunspot groups emerged this week, one on September 2, two
on September 3, two more on September 4, and one each on September
5-6, followed by another on Thursday, September 7.

Average daily sunspot number was up, from 78.7 to 95.4, while
average daily solar flux was less, from 140.9 to 137.6.

Geomagnetic activity was higher. On September 2 the planetary A
index was 38, when Earth moved through a high speed solar wind. In
Alaska, the college A index at Fairbanks was 59.

Average daily planetary A index increased from 7 to 15.4, and
average middle latitude A index rose from 8.9 to 16.3.

Predicted solar flux is 155, 158 and 155 on September 8-10, 150 on
September 11-16, then 155, 150, 155 and 150 on September 17-20, 145
on September 21-22, 150 on September 23-24, 145 on September 25, 140
on September 26-27, 135 on September 28-30, then 130, 135, 130 and
135 on October 1-4, then 140 on October 5-6, then 135, 135 and 140
on October 7-9, 145 on October 10-11, 150 on October 12-13, then
155, 150, 155 and 150 on October 14-17.

Predicted planetary A index 10 and 12 on September 8-9, 8 on
September 10-13, then 5, 8, and 12 on September 14-16, 8 on
September 17-18, 5 on September 19-22, 12 on September 23, 5 on
September 24-27, then 8, 12, 5 and 12 on September 28 through
October 1, then 12, 10, 12 and 10 on October 2-5, and 5 on October
6-10, then 10, 8 and 12 on October 11-13, and 8 on October 14-15,
and 5 over the following week.

I observed interesting 12 meter propagation using FT8 on September
4, at 1745 UTC with https://pskreporter.info/pskmap.html in which my
signal was only received over a narrow 300 mile band hugging the East
Coast from Maine to Florida, all signal reports between 2200 to 2500
miles away, nowhere else.

Three hours later at 2045 UTC, the reports along the coast expanded
to 600 miles, 2000 to 2600 miles wide.

Later at 2300 UTC it was the same pattern, but a 200 mile band,
2300-2500 miles wide.

The next day at 1700 UTC it was an arc from Virginia to South Texas,
1700 to 2300 miles. At 1715 UTC it drifted to coverage of 1750 to
2600 miles.

Before FT8 and pskreporter, there was no practical way for me to
observe any of this. Who knew?

Rick Cochran, WO8L wrote:

"So, despite all of the indicators being pretty good, why are the
bands so terrible?

"In the nearly 60 years I've been a ham this Sun cycle has
consistently been a dud compared to past cycles, especially during
the day.

"So many of us would like to know why."

I replied:

"Good question. You aren't the only one to ask."

There is a theory that carbon in the atmosphere or a warming climate contributes to this, but I do not understand the mechanism. K9LA
told me that models do not support this, but at the moment I cannot
recall what those models are. This issue was discussed in previous
bulletins.

Another theory is that this is a perception issue related to the
widespread adoption of FT8, in which users of traditional modes see
less activity on CW and SSB and perceive poorer propagation as a
result.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - September 7, 2023, from F.K. Janda, OK1HH:

"In late August, as AR3413 approached the northwestern limb of the
solar disk, its eruptive activity began to increase, even though its
size and magnetic configuration did not suggest it. However, we
observed it at a very low angle, so we may have missed details.

"Either way, it was the source of several C- and M-class flares, at
least two of which (on August 30 and September 1) ejected CMEs. Both
hit the Earth triggering a G2 class geomagnetic storm. For shortwave propagation, this meant a significant improvement and increase in
MUF in the positive phase of the disturbance on 2 September
0900-1300 UTC, followed by a deterioration for the next few days.

"AR3413 meanwhile, continued with increased eruptive activity on the
Sun's far side, including a massive CME on 5 September, but it no
longer affected the Earth. It merely 'ripped off the tail' (a
disconnection event) of comet Nishimura (C/2023 P1), which is
approaching the Sun. Its closest approach will be on September 17.

"A relative improvement in shortwave propagation did not occur until
September 5, with a jump in solar wind speed at 1439 UTC. Meanwhile,
active region AR3421 began to grow significantly around the central
meridian.

"The magnetic configuration points to the possibility of
geoeffective flares. This was followed by the growth of other active
regions in the northeast of the solar disk, so that solar activity
remains elevated. Since we expect the Earth's magnetic field to calm
down, shortwave propagation conditions should gradually improve.
Seasonal changes as the equinoxes approach will also contribute to
this."

The Autumnal Equinox in the northern hemisphere is just two weeks
away.

Here is a solar cycle prediction:

https://bit.ly/45Gxb1n

Nice video, once you get past the ads:

https://www.dailymotion.com/video/x8nub71

A "Solar Orbiter EUI" video from Max White, M0VNG and the European
Space Agency:

https://bit.ly/44JG2hr

Send your tips, reports, observations, questions, and comments to
k7ra@arrl.net . When reporting observations, don't forget to tell us
which mode you were operating.

Also, check this article from September, 2002 QST:

https://bit.ly/3Rc8Njt

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 August 31 through September 6, 2023 were 77, 83,
77, 79, 100, 121, and 131, with a mean of 95.4 10.7 cm flux was
139.9, 135.8, 131.2, 130.5, 136, 142.9, and 147.1, with a mean of
137.6. Estimated planetary A indices were 6, 12, 38, 25, 8, 11, and
8, with a mean of 15.4. Middle latitude A index was 8, 15, 25, 28,
14, 14, and 10, with a mean of 16.3.
NNNN
/EX


--- MBSE BBS v1.0.8.4 (Linux-x86_64)
* Origin: American Radio Relay League (3:633/280.2@fidonet)

SB PROP @ ARL $ARLP036
ARLP036 Propagation de K7RA

ZCZC AP36
QST de W1AW
Propagation Forecast Bulletin 36 ARLP036

From Tad Cook, K7RA

Seattle, WA September 20, 2024
To all radio amateurs

SB PROP ARL ARLP036
ARLP036 Propagation de K7RA

Solar activity was quiet over the past week, but geomagnetic numbers were
way, way up.


Average daily sunspot numbers dropped from 178.4 to 120, and average daily solar flux from 223.7 to 175.7.


Average daily planetary A index rocketed from 7.9 to 35.7, and middle
latitude numbers from 11.1 to 23.4.


Six new sunspot groups emerged over the past week; one each on September 13
and 14, two on September 16, and two each on September 17 and 18.


Predicted solar flux is 160 and 155 on September 20-21, 150 on September
22-26, then a huge leap to 230 and 225 on September 27-28, 240 on September
29 through October 2, 230 on October 3, 220 on October 4-5, then 215, 205 and 207 on October 6-8, 201, 186 and 172 on October 9-11, 173 and 175 on October 12-13, 170 on October 14-16, 165 on October 17-18, 170 on October 19, 225 on October 20-21, then 230, 225, 230 and 225 on October 22-25, then 240 on
October 26-29.


Predicted planetary A index is 5, 10 and 8 on September 20-22, 5 on September 23-26, then 25, 15 and 10 on September 27-29, then 5 on September 30 through October 4, 10 on October 5-6, and 5 on October 7-9, 10 on October 10, 20 on October 11-13, 15 on October 14, 10 on October 15-16, then 5 on October
17-22, 25 on October 23-24, and 15 and 10 on October 25-26.


Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere - September 19, 2024 from F.K. Janda, OK1HH:


"Overall solar activity has decreased slightly in recent days, but before
that AR3825 produced energetic flares, including two of the largest: X1.3 on September 12th and a very strong X4.5 on September 14th. The arrival of the CMEs and the onset of the disturbance, expected on the afternoon of UT Sept 16th, was delayed and registered as an influx of protons in the solar wind at 22:44 UT Sept 16th. After that, a geomagnetic disturbance started to develop, which significantly affected the shortwave propagation conditions, especially on 17 September.


"A more pronounced upsurge in solar flux can be expected once the large
active regions known to be present through helioseismology start to reappear
at the eastern limb of the solar disk. This should happen around 26
September. However, a repeat of the August 28-29 disturbance is expected in
the same period. Therefore, an improvement in propagation conditions can be expected before September 26, or better yet, shortly during the onset of the disturbance-after which a deterioration will occur."


New STCE newsletter:
https://www.stce.be/newsletter/newsletter.php [ https://www.stce.be/newsletter/newsletter.php ]


The latest video from Dr. Tamitha Skov, WX6SWW:
https://youtu.be/o0HWm0W-YRw [ https://youtu.be/o0HWm0W-YRw ]

Send your tips, reports, observations, questions and comments to
k7ra@arrl.net [ mailto:k7ra@arrl.net ] . When reporting observations, don't forget to tell us which mode you were operating.


For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation [ http://www.arrl.org/propagation ] and the ARRL Technical Information Service web page at, http://arrl.org/propagation-of-rf-signals [ 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 [ http://arrl.org/the-sun-the-earth-the-ionosphere ] .


An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation [ http://arrl.org/w1aw-bulletins-archive-propagation ] .


More good information and tutorials on propagation are at http://k9la.us/ [ http://k9la.us/ ] .


Also, check this article:
https://bit.ly/3Rc8Njt [ https://bit.ly/3Rc8Njt ]
"Understanding Solar Indices" from September 2002 QST.

Instructions for starting or ending email subscriptions to ARRL bulletins are at http://arrl.org/bulletins [ http://arrl.org/bulletins ] .


Sunspot numbers for September 12 through 18 2024 were 160, 127, 136, 68, 103, 140, and 106, with a mean of 120. 10.7 cm flux was 201.2, 185.8, 172.4,
172.8, 169.2, 165.4, and 163.3, with a mean of 175.7. Estimated planetary A indices were 67, 37, 21, 19, 23, 71, and 12, with a mean of 35.7. Middle latitude A Index was 36, 22, 22, 16, 19, 39, and 10, with a mean of 23.4.

NNNN
/EX

ARRL® The National Association for Amateur Radio®
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--- MBSE BBS v1.0.8.4 (Linux-x86_64)
* Origin: American Radio Relay League (3:633/280.2@fidonet)