Subj : The K7RA Solar Update
To   : QST
From : ARRL de WD1CKS
Date : Fri Oct 18 2024 14:07:58

 10/18/2024 

Average daily sunspot numbers changed from 160 to 129.3 and average
daily solar flux from 261.3 to 194.3. Geomagnetic numbers were
higher, with planetary A index rising from 21.4 to 39.3.

Seven new sunspot groups emerged this week, with two on October 10,
two on October 13, two more October 14 and one more on October 15.

Predicted solar flux is 170, 160, and 165 on October 18-20, 170 on
October 21-22, 165 on October 23-24, 220 on October 25-26, then 225,
245, 235, 260, 245 and 235 on October 27 through November 1, and 230
on November 2-3, then 225 and 220 on November 4-5, 215 on November
6-8, 210 on November 9, 200 on November 10-12, and 205 on November
13-14 and 210 on November 15-17.

Predicted planetary A index is 15, 18, 12 and 5 on October 18-21,
then 15, 12 and 5 on October 22-24, then 5, 1, 2 and 8 on October
25-27, then 5 on October 28 to November 8, then 10 on November 9-10,
then 5 on November 11-12, 8 on November 13 and 5 on November 14-17.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere - October 17, 2024 from OK1HH:

"A week ago, we witnessed a strong geomagnetic disturbance. It
peaked on 10 October and its effects in the ionosphere were
particularly evident on 11 October. The recovery from the
disturbance continued until 14 October, but was interrupted by a
further rise in geomagnetic activity on 15-16 October.

"Ionospheric shortwave propagation conditions were generally poor
throughout the period. They did not even improve to average levels.
This development was due to the coincidence with a decrease in total
solar activity."

The latest report from Dr. Tamitha Skov, WX6SWW:

https://youtu.be/warCdMmyE98[1]

An article on the peak of Solar Cycle 25:

https://www.inceptivemind.com/blurb/sun-reaches-maximum-phase-11-year-solar-cyc
le/[2]

Send your tips, reports, observations, questions and comments to
k7ra@arrl.net[3]. 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[4] and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals[5]. For
an explanation of numbers used in this bulletin, see
http://arrl.org/the-sun-the-earth-the-ionosphere[6] .

An archive of past propagation bulletins is at
http://arrl.org/w1aw-bulletins-archive-propagation[7] . More good
information and tutorials on propagation are at http://k9la.us/[8] .

Also, check this article:

https://bit.ly/3Rc8Njt[9]

"Understanding Solar Indices" from September 2002 QST.

Instructions for starting or ending email subscriptions to ARRL
bulletins are at http://arrl.org/bulletins[10] .

Sunspot numbers for October 10 through 16 2024 were 150, 130, 95,
108, 146, 141, and 135, with a mean of 129.3. 10.7 cm flux was
216.3, 213.9, 213.6, 194.9, 181.9, 172, and 167.7, with a mean of
194.3. Estimated planetary A indices were 96, 116, 20, 5, 8, 15, and
15, with a mean of 30.3. Middle latitude A Index was 50, 68, 16, 3,
6, 9, and 11, with a mean of 23.3.

ÿ


[1] https://youtu.be/warCdMmyE98
[2] https://www.inceptivemind.com/blurb/sun-reaches-maximum-phase-11-year-solar-cycle/
[3] mailto:k7ra@arrl.net
[4] http://www.arrl.org/propagation
[5] http://arrl.org/propagation-of-rf-signals
[6] http://arrl.org/the-sun-the-earth-the-ionosphere
[7] http://arrl.org/w1aw-bulletins-archive-propagation
[8] http://k9la.us/
[9] https://bit.ly/3Rc8Njt
[10] http://arrl.org/bulletins

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