SB PROP @ ARL $ARLP001
ARLP001 Propagation de K7RA

ZCZC AP01
QST de W1AW
Propagation Forecast Bulletin 1 ARLP001

From Tad Cook, K7RA

Seattle, WA January 6, 2023
To all radio amateurs

SB PROP ARL ARLP001
ARLP001 Propagation de K7RA

Two new sunspot groups emerged on December 29, one more on December
30 and another on January 1, then two more on January 5.

Solar activity was a little higher, with average daily sunspot
number rising from 96.1 to 97, and solar flux averages rose 14
points to 157.8.

On Thursday, January 5 the sunspot number rose to 103, above the
average of 96.1 over the previous seven days.

Predicted solar flux is 154 on January 6, 152 on January 7-8, 150 on
January 9, 148 on January 10-11, then 146, 148 and 145 on January
12-14, 140 on January 15-16, 145 on January 17-19, 150 and 155 on
January 20-21, 160 on January 22-23, 165 on January 24-26, then 160,
155, 155, 158 and 155 on January 27-31, 150 and 148 on February 1-2,
145 on February 3-4, 140 on February 5-6, 150 on February 7-9, 145
on February 10, 140 on February 11-12, and 145 on February 13-15.

Predicted planetary A index is 12 and 8 on January 6-7, 5 on January
8-16, then 8, 12, 25, 20 and 10 on January 17-21, 5 on January
22-24, then 8, 28, 15 and 10 on January 25-28, and 5 on January
29-30, 18 on January 31 through February 1,15 and 10 on February
2-3, and 5 on February 4-12.

OK1HH wrote:

"Solar activity increased so rapidly in recent years that earlier
last year it already reached the level predicted for July 2025, the
predicted peak of the current 25th solar cycle. The year 2022 ended
with the highest monthly sunspot count in 7 years.

"Solar flares are already routinely of moderate magnitude (M-class
in X-rays), while geomagnetic disturbances are so far only very
rarely in a higher class than G1 (minor). In the G1 class was also
the disturbance on 30 December, which was triggered by a CIR
(co-rotating interaction region) impact, as predicted.

"This week the Earth is in the impact zone of possible eruptions in
the AR3176 sunspot group directly opposite our planet, which
produces M-class solar flares. The strongest so far, on December 30
at 1938 UTC, was class M3.7, which sent a CME toward Earth with an
expected arrival on January 4 - and the prediction proved correct -
the disturbance began at 0254 UTC.

"The CMEs filled the space between the Sun and Earth, and clouds of
solar plasma shielded the incoming cosmic rays enough to reach a
six-year low.

"Thus, since 26 December, we can observe the 'Forbush Decline,'
named after the American physicist Scott Forbush, who studied cosmic
rays in the early 20th century and first noticed the relationship
between them and solar activity. With more CMEs hitting Earth, the
cosmic ray decline will grow.

"On January 3 at 1058 UTC, something exploded on the far side of the
Sun. The Solar and Heliospheric Observatory (SOHO) detected a bright
CME sweeping across the southeastern limb of the Sun. The source of
the outburst was likely the old sunspot AR3163, which has been on
the Sun's far side for the past two weeks. We are now starting to
see it on the solar disk as AR3182, and we might tentatively expect
an X-class flare from it.

"The Geminid meteor shower is coming to Earth these days. On the
first three days of January, the most meteors arrived on January 3
at 2127 UTC when the Zenithal Hourly Rate (ZHR) of 125.3 was
calculated. Also, the activity of the sporadic-E layer in the
ionosphere increased, which we immediately noticed in the fading
shortwave propagation conditions (because sporadic-E is sporadic).

"ZHR (Zenithal Hourly Rate) of a meteor shower is the number of
meteors a single observer would see in an hour of peak activity if
it was at the zenith, assuming the observing conditions are
excellent (when and where stars with apparent magnitudes up to 6.5
are visible to the naked eye)."

OK1HH mentioned sunspot numbers are ahead of the consensus forecast
for Solar Cycle 25, so we will compare averages from a year ago with
current numbers.

In Propagation Forecast Bulletin ARLP001 for 2022, the average
sunspot number reported was 36.4, and 97 in the current report.
Average solar flux a year ago was 91.4, compared to 157.8 this week.

Reader David Moore sends along this link about our Sun's corona:

https://bit.ly/3XaNsXz

Here is an article on Siberian Radioheliograph:

https://bit.ly/3vGFJVm

Solar outburst:

https://bit.ly/3X6oUio

A record of old sunspot numbers can be found here:

https://bit.ly/3XbX8B2

Solar Terrestrial Activity Report:

http://www.solen.info/solar/

Identifying unknown HF signals:

https://www.sigidwiki.com/wiki/Category:HF

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 29, 2022 through January 4, 2023 were
113, 121, 82, 94, 94, 89, and 86, with a mean of 97. 10.7 cm flux
was 162.8, 178.3, 164.9, 152.6, 146.4, 148.5, and 151, with a mean
of 157.8. Estimated planetary A indices were 11, 31, 16, 14, 8, 7,
and 21, with a mean of 15.4. Middle latitude A index was 8, 22, 10,
9, 5, 5, and 17, with a mean of 10.9.
NNNN
/EX


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

SB PROP @ ARL $ARLP001
ARLP001 Propagation de K7RA

ZCZC AP01
QST de W1AW
Propagation Forecast Bulletin 1 ARLP001

From Tad Cook, K7RA

Seattle, WA January 5, 2024
To all radio amateurs

SB PROP ARL ARLP001
ARLP001 Propagation de K7RA

Only four new sunspot groups emerged over the past week, one on
December 28, another on December 31, and two more on January 2 and
3.

Solar indices sank. The average daily sunspot number declined from
114.4 to 63.4, and average daily solar flux from 172.6 to 141.9.

Average daily planetary A index rose from 8.4 to 6.7 and middle
latitude numbers from 4 to 5.1.

Predicted solar flux over the next few weeks is 130 on January 5-7,
135 on January 8-10, 140 on January 11, 155 on January 12-14, then
160, 165, 160 and 155 on January 15-18, 150 on January 19-21, then
145 and 140 on January 22-23, and 135 on January 24-26, 130 and 145
on January 27-28, 140 on January 29-30, 145 on January 31 through
February 1, 150 on February 2-4, 155 on February 5-6, 160 on
February 7, and 155 on February 8-10.

This is from the Thursday forecast, which looks substantially weaker
than the Wednesday outlook in Thursday's ARRL Letter.

Predicted planetary A index is 5, 5, 8, 10 and 8 on January 5-9,
then 5 on January 10-26, then 8, 15 and 12 on January 27-29, 8 on
January 30-31, 5 on February 1-3, then 10, 10 and 8 on February 4-6,
and 5 on February 7-18.

Solar activity looks soft of late, but perhaps we will see a double
peak in this cycle.

But look at this illustration comparing progress in the current
cycle against the last cycle, month by month since each minimum:

https://bit.ly/4aMBefh

Page down to the second chart, labeled "Solar Cycle Comparison."

There is some confusion because of the similarity in colors.

The red line is the last cycle, probably smoothed by monthly
averages. The blue green line inside it is probably a conventional
moving average with points on the line smoothed over a year.

The yellow line is the current cycle, also probably smoothed over a
year, and the light blue green line is the current cycle, probably
smoothed with monthly numbers.

This looks promising for more activity to come.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere, January 4, 2024, from F.K. Janda, OK1HH.

"The first celebrations of the end of the calendar year in Western
civilization are associated with the person of the canonized Pope
Silvester I, who died on the last day of the year 335. However, no
one expected that December 31, 2023, would be celebrated with
fireworks all the way on the Sun.

"Helioseismological observations focused on a large active region
approaching the northeastern limb of the solar disk from the far
side, and large spots on the far side of the Sun were seen by the
camera of the Perseverance rover on Mars. But no one actually
expected a proton solar flare, the largest in the current
eleven-year cycle.

"The X5.0 eruption in X-ray band 1 to 8 Angstrom occurred at 2155
UTC in NOAA/SWPC 3536 and was the largest observed eruption since
the X8.2 eruption on September 10, 2017. In the same sunspot group
(in the previous solar rotation), an X2.8 eruption was observed on
December 14, 2023, whereby this was the strongest since the
beginning of Solar Cycle 25 up to that point.

"In particular, however, it also contributed to expectations of a
further increase in activity in the next year or two.

"Four days later, AR3536 is no longer as large as it was on the
Sun's far side and about half the size it was in December as AR3514,
but it is still capable of producing moderate solar flares. Now AR
3536 is approaching the central meridian from where a possible CME
(within the next week) could already be hitting Earth. At the same
time, we expect a further increase in solar radiation , which could
improve propagation conditions in the DX bands. But of course, also
worsen if a possible magstorm lasts longer or even starts at night."

I was on a video session on Sunday with Dr. Tamitha Skov and her
Patreon subscribers. She was displaying the Sun in real time when
the big flare happened. It was quite dramatic.

She was also using a setting on Pskreporter.info that I had never
tried before. The settings are, "On All Bands, show Signals,
sent/rcvd by Anyone, using All Modes, over the last" (pick a time).

In real time we could immediately see the effects the flare had on
propagation. It was fascinating. I use this regularly now to check
worldwide propagation on all HF bands.

I asked her if her husband was an astrophysicist, and she said,
"No." She yelled, "Hey Kent! Come in here."

Kent is an actor, an acting coach, a producer, and a writer. I asked
how they met, which was hilarious. You won't read it here, but you
can email me if you want more details.

Scott Craig, WA4TTK years ago built some Windows software that sucks
up solar data from this bulletin and displays it in a nice format on
his Solar Data Plotting Utility. To update it, you just create a
plain .txt file of this bulletin and point the program to the file.

You can download it from http://www.craigcentral.com/sol.asp and
also on the same page is an updated data file good through 1/3/2024.

The latest video from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/WN4iqCq4LAU

An article about a powerful solar storm:

https://bit.ly/3RO0Ek5

Two articles about a solar storm that will hit hard:

https://bit.ly/3vqMhL9

https://bit.ly/41L5SBI

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.

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/ .

Also, check this article:

https://bit.ly/3Rc8Njt

Instructions for starting or ending email distribution of ARRL
bulletins are at http://arrl.org/bulletins .

Sunspot numbers for December 28, 2023, through January 3, 2024, were
83, 92, 48, 55, 44, 59, and 63, with a mean of 63.4. 10.7 cm flux
was 146.7, 142.9, 139.7, 146.2, 135.7, 142.1, and 140.2, with a mean
of 141.9. Estimated planetary A indices were 3, 6, 5, 4, 10, 8, and
11, with a mean of 6.7. Middle latitude A index was 2, 6, 4, 2, 6,
8, and 8, with a mean of 5.1.
NNNN
/EX


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