SB PROP @ ARL $ARLP029
ARLP029 Propagation de K7RA

ZCZC AP29
QST de W1AW
Propagation Forecast Bulletin 29 ARLP029

From Tad Cook, K7RA

Seattle, WA July 21, 2023
To all radio amateurs

SB PROP ARL ARLP029
ARLP029 Propagation de K7RA

Average daily sunspot numbers declined, but average daily solar flux
increased. Sunspot averages were 181.9 last week, and 130.6 this
week. Average daily solar flux increased from 179.4 to 190.5.

Two new sunspot groups emerged on July 14, three more on July 17 and
another two on July 19.

Average daily planetary and middle latitude A index were both 12.9
this week, rising from 8.6 and 8.1.

Predicted solar flux is 185 on July 21-23, then 180, 178, 175 and
170 on July 24-27, 165 on July 28-29, 170 on July 30-31, 165 on
August 1-4, then 170, 175, 175 and 170 on August 5-8, 165 on August
9-11, 170 on August 12, 175 on August 13-14, and 170 on August
15-19, 160 on August 20-23, 165 on August 24-25, then 170 on August
26-27 and 165 on August 28-31.

Predicted planetary A index is 20, 12, 8, 12 and 10 on July 21-25, 5
on July 26 through August 2, then 10 and 8 on August 3-4, 5 on
August 5-14, then 12, 8 and 8 on August 15-17, and 5 on August
18-29.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere for July 20, 2023 from OK1HH.

"We've seen another seven days of mostly moderate solar activity,
with almost daily eruptions of moderate magnitude on the Sun. Some
of these have been the source of CMEs. If the Earth has been
affected by them, a geomagnetic disturbance followed, with a drop in
MUF and a worsening of HF propagation in the process.

As predicted, the expected CME hit the Earth's magnetic field on the
afternoon of 14 July (as part of the Bastille Day celebrations, but
not nearly as strongly as in 2000).

Another CME left the Sun on 14 July, and yet another on July 15.
Because the cloud of later ejected solar plasma was faster, it
cannibalized the previous CME. Together, they hit the Earth on July
18.

But by then AR3363 had already produced a significant long-lasting
M6-class solar flare, and energetic protons accelerated by this
flare reached the Earth and caused a radiation storm. Although MUFs
were quite high, HF conditions were adversely affected by frequent
occurrences of attenuation.

Another CME hit the Earth on 20 July, registered by the Earth's
magnetic field at 1708 UTC.

Further developments were predicted up to G1 to G2 class geomagnetic
storms, with a small probability also of G3, but by then this report
will have been completed and sent out.

Finally, just a little note on the consequences of global change: it
has been manifested in the last eleven-year cycles, in the Earth's
troposphere it is the result of warming, but in the ionosphere it is
rather the opposite. It has been the subject of a number of
scientific papers in recent years.

It is crucial for us, for amateur radio practice, that the current
MUFs are lower than those calculated from sunspot counts for most of
the twentieth century. Therefore, we should input Ri (or solar flux
SFU) into forecast programs lower than what is currently measured
and published.

F.K. Janda, A.R.S. OK1HH http://ok1hh.nagano.cz/ "

News from N8II in West Virginia.

"The bands are in much better shape than most hams realize; activity
levels are normally quite low this summer. In the IARU contest I
observed 15M open to Europe through 0300 UTC and I had QSOs with
Indonesia, China, Nepal, Japan, Central/Western Siberia, Kazakhstan,
and the Philippines in the 2300-0300 UTC period.

I copied GR2HQ (Great Britain HQ station) on 10M CW at 0140 UTC. At
1100 UTC on 15M EU and Central/West Asia were very loud and I
started running a pile up on CW.

The Far East was also in on 15M around 1400 UTC Saturday when I
worked a loud Japanese station.

During the evening/night EU signals were extremely loud on 20M. I
also worked a few EU on 10M 1300-1400 UTC Saturday thanks to
Sporadic E and also caught Z30HQ (Macedonia HQ) on 10M CW Sunday
about 1130 UTC. I worked 697 QSOs concentrating on DX on the high
bands in less than 12 hours with 100 W.

Africa is workable on 10-15M well into our evening as are South
Pacific stations.

Sporadic E this year seems somewhat attenuated, but Es was good from
here and great from the Central/Western USA during the June VHF
contest. I made about 170 CW/SSB QSOs."

CNN presented a smart piece on the sunspot cycle peaking sooner than
expected. https://bit.ly/3rzNJJ6

Double peaked flare. https://bit.ly/46ZoznE

Astronomy club observes sunspots. https://bit.ly/46SaacR

Aurora. https://bit.ly/44FxM2U

Scientific American. https://bit.ly/3rHzGkB

Early peak. https://bit.ly/44Aa7AF https://bit.ly/3rEa0Wj

Cannibal eruption. https://bit.ly/3Q5dv1W

Great video of eruption. https://youtu.be/YOzHHM4B4gA

The latest from Space Weather Woman Dr. Tamitha Skov, WX6SWW.

https://youtu.be/KsKDVOuboyw

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 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 .

Also, check this article from September, 2002 QST:

https://www.arrl.org/files/file/Technology/tis/info/pdf/0209038.pdf

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 July 13 through 19, 2023 were 146, 141, 96, 99,
149, 142, and 141, with a mean of 130.6. 10.7 cm flux was 202.9,
180.6, 178.5, 184.3, 180, 218.5, and 188.9, with a mean of 190.5.
Estimated planetary A indices were 7, 20, 8, 10, 24, 16, and 5, with
a mean of 12.9. Middle latitude A index was 9, 17, 9, 13, 19, 16,
and 7, with a mean of 12.9.
NNNN
/EX


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

SB PROP @ ARL $ARLP029
ARLP029 Propagation de K7RA

ZCZC AP29
QST de W1AW
Propagation Forecast Bulletin 29 ARLP029

From Tad Cook, K7RA

Seattle, WA August 2, 2024
To all radio amateurs

SB PROP ARL ARLP029
ARLP029 Propagation de K7RA

High solar activity continued this week, with average daily sunspot number changing from 208.1 to 208.9 and average daily solar flux from 193 to 207.3. Average daily planetary A index shifted from 6 to 14, and average middle latitude A index from 7.3 to 13.1.


The Penticton observatory in British Columbia reported a solar flux of 400.7
at noon on July 30, which we threw out due to obvious overload at the
facility. We used values from the morning and afternoon to come up with our estimate instead.


Nine new sunspot regions emerged. There was one on July 25, two on July 26, another on July 28 and another on July 29, two more on July 30 and another
two on July 31.


Predicted solar flux is 235 on August 2, 230 on August 3, 220 on August 4 to
8, 190 on August 9 to 11, 195 on August 12 and 13, 190 on August 14 to 17,
185 on August 18, then 180 on August 19 to 24, 190 on August 25 to 31, 180 on September 1 and 2, 185 on September 3 and 4, and 190 on September 5 to 7.


The planetary A index prediction calls for 10, 30, 25 and 8 on August 2 to 5,
5 on August 6 to 21, then 10 and 8 on August 22 and 23, and 5 on August 24 to September 11.


Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere
for August 1, 2024 from OK1HH.


The largest solar flare so far in the 25th 11-year cycle occurred on July 23
on the far side of the Sun. Fortunately, it was observable by the Solar
Orbiter (SolO), a solar probe designed to study the Sun from a heliocentric orbit. The spacecraft was manufactured by Airbus for ESA. The individual measuring instruments and sensors were supplied by ESA Member States,
including the Czech Republic, while the US NASA is also involved in the
probe. The spacecraft was launched on 10 February 2020 on Atlas V rocket from Cape Canaveral.


Solar Orbiter was in an ideal position to observe the eruption, directly invisible from Earth now. On July 24, SolO was directly hit by particles from the CME, accelerated in a shock front, which increased their energy (a
similar ESP event caused the "Great Quebec Blackout" in March 1989, but fortunately only SolO was hit this time).


Over the past seven days, the Sun's rotation has shifted the sunspot active regions from the southeast quadrant of the solar disk to the southwest, or
the area where Earth is more likely to be hit by particles ejected from the Sun. Strong eruptive activity has continued. If we just had the Sun overhead, we could register the Dellinger effect, a shortwave blackout, which almost always hit the lower shortwave bands and only rarely the entire shortwave range.


Even a G3 geomagnetic disturbance was predicted, but so far it has been a G2. It could have been worse due to "cannibal CMEs" that made way for other CMEs from subsequent eruptions. Even so, due to "appropriate" timing, there was a significant drop in daily MUF values and an overall worsening of shortwave propagation conditions. The worst days were 26 and 30 and 31 July. We
continue to observe several unstable sunspot regions on the Sun. Therefore, further similar disturbances are very likely.


Recent report from Tamitha Skov: https://bit.ly/3A6XClU [ https://bit.ly/3A6XClU ]


How current storm differs from May 11:
https://bit.ly/46thuvr [ https://bit.ly/46thuvr ]

Are we at solar max?
https://bit.ly/3yuxMYn [ https://bit.ly/3yuxMYn ] (Thanks to NN4X.)

Frank Donovan, W3LPL sent this URL, commenting that it contains much more detail about July 23 solar events:

www.stce.be/newsletter/pdf/2024/STCEnews20240801.pdf [ https://www.stce.be/newsletter/pdf/2024/STCEnews20240801.pdf ]


Kepler's sketches: https://bit.ly/3SB5gvg [ https://bit.ly/3SB5gvg ]

Stormy: https://bit.ly/3YozbdL [ https://bit.ly/3YozbdL ]

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 www.arrl.org/propagation [ http://www.arrl.org/propagation ] and the ARRL Technical Information Service web page at www.arrl.org/propagation-of-rf-signals [ http://arrl.org/propagation-of-rf-signals ] .


For an explanation of numbers used in this bulletin, see www.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 www.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: https://bit.ly/3Rc8Njt [ https://bit.ly/3Rc8Njt ]

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


Sunspot numbers for July 25 through 31 2024 were 171, 181, 178, 189, 211,
261, and 271, with a mean of 208.9. 10.7 cm flux was 176.2, 176.3, 203.6, 214.4, 223.1, 222.3, and 235.1, with a mean of 207.3. Estimated planetary A indices were 9, 23, 13, 7, 6, 23, and 17, with a mean of 14. Middle latitude
A Index was 9, 23, 14, 8, 7, 18, and 13, with a mean of 13.1.

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)