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SB PROP @ ARL $ARLP032
ARLP032 Propagation de K7RA

ZCZC AP32
QST de W1AW  
Propagation Forecast Bulletin 32  ARLP032
From Tad Cook, K7RA
Seattle, WA  August 12, 2022
To all radio amateurs 

SB PROP ARL ARLP032
ARLP032 Propagation de K7RA

Solar activity did a rebound this week, back to more active levels.

Average daily sunspot number increased from 36.6 to 65.4.

Average daily 10.7 cm solar flux rose from 95.7 to 111.9.

Solar wind caused geomagnetic numbers to rise, with average
planetary A index going from 7.7 to 14.4, and middle latitude
numbers from 8.6 to 12.1.

An improved outlook shows solar flux over the next month peaking at
116 on September 2 to 4.  The forecast from USAF/NOAA on Thursday
evening was improved from Wednesday.

A look at ARLP032 from 2021 gives a perspective on solar cycle
progress.  A year ago, average sunspot number was 6 and average
solar flux was just 74.8.  Quite a difference from 65.4 and 111.9
during the past week.

Predicted flux values are 115 on August 12 to 14, 110 on August 15
to 18, 108 on August 19, 104 on August 20 and 21, then 98, 100, 102,
100, 102, and 100 on August 22 to 27, then 102 on August 28 to 30,
then 108 and 114 on August 31 and September 1, 116 on September 2 to
4, 112 on September 5 to 7.  110 on September 8 and 9, then 108 on
September 10 to 12, 106 on September 13, then 104 on September 14 to
16, 102 on September 17 and 98 on September 18.

Predicted planetary A index is 12 on August 12, 5 on August 13 to 16
then 10, 12 and 15 on August 17 to 19, 8 on August 20 and 21, 5 on
August 22 to 26, 12 on August 27, 8 on August 28 to 30, 5 on August
31 through September 2, then 14, 18, 14, 10 and 8 on September 3 to
7, and 5 on September 8 to 12, then 22 on September 13, 15 on
September 14 and 15, 8 on September 16, and 5 on September 17 to 22.

OK1HH commented:

"A geomagnetic disturbance rarely comes completely unexpectedly.
And even more so in a situation where its source cannot be located
(or selected from several locations).  Moreover, lasting five days.
All this happened between August 7th and 11th.

At higher latitudes, the 'STEVE' phenomenon was sighted on August 7
(Strong Thermal Emission Velocity Enhancement).  STEVE is a recent
discovery.  It looks like an aurora, but it's not.

https://en.wikipedia.org/wiki/STEVE

It all started with a positive phase of disturbance in the
ionosphere, when shortwave propagation improved.  The development
continued with a deterioration of propagation in the negative phase
on August 8, followed by generally below average conditions in the
following days.  With a strong influence of sporadic layer E, whose
activity usually increases as the Perseids meteor shower approaches
maximum (expected on 12 and 13 August).  They are also called the
'Tears of St. Lawrence'.

Starting August 12 onward, we expect a longer mostly quiet period."

NASA expects increasing activity:

https://bit.ly/3QjOLk5

Always appreciate The Sun Now page from the Solar Dynamics
Observatory:

https://sdo.gsfc.nasa.gov/

Yet another cycle prediction method:

https://bit.ly/3SKm29J

Tamitha Skov, WX6SWW has a 200 minute part 2 of a course on ground
effects:

https://youtu.be/cOom5LQ_LBY

Send your tips, reports, observations, questions and comments to
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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 4 through 10, 2022 were 52, 69, 69, 87,
63, 58, and 60, with a mean of 65.4.  10.7 cm flux was 108.8, 112.2,
116.3, 116.1, 113, 109.4, and 107.6, with a mean of 111.9.
Estimated planetary A indices were 6, 6, 4, 24, 31, 19, and 11, with
a mean of 14.4.  Middle latitude A index was 7, 7, 5, 20, 21, 15,
and 10, with a mean of 12.1.
NNNN
/EX

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