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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 3, 2021
To all radio amateurs

SB PROP ARL ARLP036
ARLP036 Propagation de K7RA

Solar activity is on the upswing this week. Average daily sunspot
numbers increased from 21.7 to 50.6, with a high of 77 last
Saturday, August 28. Average daily solar flux rose from 78.5 to 88.

Average daily planetary A index increased from 4.7 to 9.6, and
average daily middle latitude A index went from 5.7 to 10.7.
Geomagnetic activity peaked on August 27 and 28 due to a coronal
mass ejection.

New sunspot regions appeared on August 26 and 27, and on September 2 Spaceweather.com reported "New Sunspot, Rapidly Growing" to announce
the emergence of AR2863.

Predicted solar flux looks promising, particularly after
mid-September, at 85 and 82 on September 3 and 4, 80 on September 5
and 6, 78 on September 7, 75 on September 8 to 10, 80 on September
11 to 14, 85 on September 15, 90 on September 16 to 30, 85 on
October 1, and 80 on October 2 to 10. Flux values rise to 90 again
after October 12 in this forecast from September 2.

Predicted planetary A index is 8, 5, 10 and 8 on September 3 to 6, 5
on September 7 to 10, then 10 and 8 on September 11 and 12, 5 on
September 13 to 20, 8 on September 21, 5 on September 22 to 25, then
a big jump to 25, 8, 18, 8, and 12 on September 26 to 30, and back
to 5 on October 1 to 7, then 10 and 8 on October 8 and 9.

Geomagnetic activity forecast for the period September 3 to 29,
2021, from F. K. Janda, OK1HH.

"Geomagnetic field will be
Quiet on September 7 and 8, 10, 14 and 15, 17 and 18, 28 and 29
Quiet to unsettled on September 4 and 5, 13, 16, 19, 22, 25, 27
Quiet to active on September 3, 6, 9, 11 and 12, 20 and 21, 26
Unsettled to active on September 23 and (- 24)
Active to disturbed, nothing predicted

Remarks:
- Parenthesis means lower probability of activity enhancement.
- The situation is confusing, the configuration of active regions
and coronal holes is variable, so this time it is not possible to
make a so-so reliable forecast. Here and there it happens before
solar activity rises.
- F. K. Janda will travel next week, therefore next forecast will be
compiled on September 16."

The autumnal equinox will be on Wednesday, September 22 in the
Northern Hemisphere, always a welcome event for HF propagation.
Solar flux is forecast to be higher at that time, also a good sign.

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 August 26 through September 1, 2021 were 47, 73,
77, 44, 41, 37, and 35, with a mean of 50.6. 10.7 cm flux was 88.6,
89.5, 89.9, 88.7, 90.6, 84.4, and 84.2, with a mean of 88.
Estimated planetary A indices were 6, 20, 14, 8, 7, 7, and 5, with a
mean of 9.6. Middle latitude A index was 6, 19, 17, 9, 9, 9, and 6,
with a mean of 10.7.
NNNN
/EX

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XPost: rec.radio.shortwave, rec.radio.info

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

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XPost: rec.radio.shortwave, rec.radio.info

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

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