[SFDXA] ARLP045 Propagation de K7RA

Fri Nov 22 13:17:06 EST 2024

ARLP045 Propagation de K7RA

SB PROP @ ARL $ARLP045

ARLP045 Propagation de K7RA

ZCZC AP45

QST de W1AW

Propagation Forecast Bulletin 45 ARLP045

From Tad Cook, K7RA

Seattle, WA November 22, 2024

To all radio amateurs

SB PROP ARL ARLP045

ARLP045 Propagation de K7RA

Solar activity was lower this reporting week, November 14-20, with the 
average daily sunspot number down from 141.6 to 99.3, and solar flux 
from 203.7 to 152.4. Geomagnetic indicators were quiet.

This follows a period during August and October when it seemed we must 
be at the peak of Solar Cycle 25. But we won't know that until nearly a 
year after solar max, when a long moving average of daily sunspot 
numbers is examined.

Predicted solar flux is 170 on November 22, 175 on November 23-24, 180 
on November 25-26, 175 and 180 on November 27-28, 250 on November 29-30, 
then 240, 230, 220, and 210 on December 1-4, 205 on December 5-6, then 
200, 180, 170 and 150 on December 7-10, 145 on December 11-12, then 149, 
145, and 230 on December 13-15, 235 on December 16-17, 240 on December 
18-20, 245 on December 21-22, then 240, 245 and 255 on December 23-25.

Predicted planetary A index is 8 on November 22-25, 5 on November 26-29, 
then 10, 12, 9, 8, 7 and 5 on November 30 through December 5, 12 on 
December 6-7, then 10, 5, 5, 10, 15 and 10 on November 8-13, then 8 on 
December 14-15, then 5 and 12 on December 16-17, and 5 on December 18-21.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's 
Ionosphere - November 21, 2024, from F. K. Janda, OK1HH:

"During November, solar activity was relatively lowest in the middle of 
the month, which happened after the large sunspot groups in the west of 
the disk had set and before the larger groups in the east came out. The 
largest of these is designated AR3901 and will pass through the central 
meridian on November 23. Solar activity will therefore still increase 
slightly. A more significant rise could perhaps be expected after the 
rise of the other groups, but their current activity on the far side of 
the Sun does not appear to be great for now.

"The low number and small area of coronal holes are the likely cause of 
the geomagnetically quieter development, which is likely to continue.

"November belongs to the Autumn DX season, therefore we can expect 
continued above-average shortwave propagation. They were admittedly a 
little worse as a result of the drop in solar radiation, but the rest of 
the month could, yet, correct this. Which is true for the northern 
hemisphere of the Earth, where the season of favorable propagation 
conditions on the longer shortwave bands is already beginning!"

Images from the European Space Agency:

https://tinyurl.com/42r665y9 
<https://arrl.informz.net/z/cjUucD9taT0zMTk1ODQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT0zNTk4NTQwOA/index.html>

From "Space Daily," solar orbiter images:

https://tinyurl.com/bdz33ake 
<https://arrl.informz.net/z/cjUucD9taT0zMTk1ODQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT0zNTk4NTQwOQ/index.html>

https://tinyurl.com/yvkf66u2 
<https://arrl.informz.net/z/cjUucD9taT0zMTk1ODQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT0zNTk4NTQxMA/index.html>

Send your tips, reports, observations, questions and comments to 
k7ra at arrl.net <mailto:k7ra at 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 
<https://arrl.informz.net/z/cjUucD9taT0zMTk1ODQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT0zNTk4NTQxMQ/index.html> 
and the ARRL Technical Information Service web page at, 
www.arrl.org/propagation-of-rf-signals 
<https://arrl.informz.net/z/cjUucD9taT0zMTk1ODQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT0zNTk4NTQxMg/index.html>. 
For an explanation of numbers used in this bulletin, see 
www.arrl.org/the-sun-the-earth-the-ionosphere 
<https://arrl.informz.net/z/cjUucD9taT0zMTk1ODQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT0zNTk4NTQxMw/index.html>.

An archive of past propagation bulletins is at 
www.arrl.org/w1aw-bulletins-archive-propagation 
<https://arrl.informz.net/z/cjUucD9taT0zMTk1ODQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT0zNTk4NTQxNA/index.html>. 
More good information and tutorials on propagation are at http://k9la.us 
<https://arrl.informz.net/z/cjUucD9taT0zMTk1ODQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT0zNTk4NTQxNQ/index.html>.

Also, check this:

https://bit.ly/3Rc8Njt 
<https://arrl.informz.net/z/cjUucD9taT0zMTk1ODQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT0zNTk4NTQxNg/index.html>

"Understanding Solar Indices" from September 2002 QST.

Instructions for starting or ending email subscriptions to ARRL 
bulletins are at www.arrl.org/bulletins 
<https://arrl.informz.net/z/cjUucD9taT0zMTk1ODQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT0zNTk4NTQxNw/index.html>.

Sunspot numbers for November 14 through 20, 2024 were 96, 71, 71, 117, 
118, 109, and 113, with a mean of 99.3. 10.7 cm flux was 146.8, 148.9, 
139.9, 146.3, 165, 157.2, and 162.6, with a mean of 152.4. Estimated 
planetary A indices were 11, 13, 8, 8, 4, 9, and 9, with a mean of 8.9. 
Middle latitude A Index was 10, 10, 8, 6, 3, 6, and 8, with a mean of 7.3.

NNNN

/EX

ARRL® The National Association for Amateur Radio®

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