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ARRL Propagation Bulletin ARLP009 (2022)

ARLP009 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 9  ARLP009
From Tad Cook, K7RA
Seattle, WA  March 4, 2022
To all radio amateurs 

ARLP009 Propagation de K7RA

Solar activity was weaker this reporting week (February 24 through
March 2) with average daily sunspot numbers weakening from 54.3 to
44, but average daily solar flux rising slightly from 95.4 to 98.5.

Geomagnetic numbers were moderate. Average daily planetary A index
declined from 9.6 to 7.3, and middle latitude index from 7.3 to 5.6.

Predicted solar flux is 110 on March 4, 108 on March 5-7, then 106,
104 and 100 on March 8-10, 99 on March 11-13, 98 on March 14, 95 on
March 15-16, then 96, 97, 98 and 99 on March 17-20, 100 on March
21-22, then 101 and 100 on March 23-24, 102 on March 25-26, then 99
and 102 on March 27-28, 105 on March 29-31, 102 on April 1-2, 101 on
April 3-4, then 100 on April 5-6, and 99 on April 7-9.

Predicted planetary A index is 12 on March 4-6, 10 on March 7, 5 on
March 8-10, then 10, 12, 8, 5 and 8 on March 11-15, 5 on March
16-17, 10 on March 18, 15 on March 19-21, 7 on March 22-24, then 5
and 10 on March 25-26, 12 on March 27-28, 8 on March 29-30, 12 on
March 31, 15 on April 1-2, then 5 on April 3-6, then 18, 15 and 8 on
April 7-9.

Here is the weekly commentary from OK1HH:

"The decline in solar activity in the second half of February might
have surprised us if it were not for the information about the
increased eruptive activity on the far side of the Sun. The farside
sunspots images were taken mainly by the STEREO-A spacecraft,
starting with the huge farside explosion, when the spacecraft
recorded a spectacular coronal mass ejection (CME) appearing in the
late hours of 15 February.

"One day later Solar and Heliospheric Observatory (SOHO) gave us a
better view of the explosion on the far side. SOHO coronagraphs have
recorded the most dramatic CME in recent years. The activity
observed beyond the eastern edge of the solar disk looked promising
several times, but after the spot groups actually came out, we
experienced only occasional eruptions of class C.

"The Earth's magnetic field activity fluctuated irregularly and
attempts to predict further developments failed. Conditions for
shortwave propagation began to improve in early March, but this was
mainly due to seasonal changes."

Here is a link to see a new telescope:

Check out the Solar Orbiter from European Space Agency:

Jeff, WA2BOT, in Connecticut wrote on March 2:


"10 Meters Long Path from East Coast USA to the Far East was amazing

"I noticed 10 meters was open to Europe at 1143Z when I first
checked band conditions.

"Operating on FT8 from Grid FN32, between 1310 GMT to 1348 GMT using
FT8. During the opening I worked: BD7MXA, VR2XYL, VR2ZXP, VR2UBC,
VR2XRW, VR2CH, JA7QVI, and 12 other stations in Japan.

"Solar Cycle 25 is just getting started and 10 meters is again,

See stunning loops of plasma:

Here is information about the termination event:

This is from a 2020 paper on "Overlapping Magnetic Activity Cycles
and the Sunspot Number," and now the paper's authors have announced
the termination event between Solar Cycles 24 and 25 has arrived:

If you would like to make a comment or have a tip for our readers,
please email the author at, .

For more information concerning shortwave radio propagation, see and the ARRL Technical Information
Service web page at, For
an explanation of numbers used in this bulletin, see

An archive of past propagation bulletins is at More good
information and tutorials on propagation are at

Instructions for starting or ending email distribution of ARRL
bulletins are at .

Sunspot numbers for February 24 through March 2, 2022 were 23, 22,
22, 48, 65, 62, and 66, with a mean of 44. 10.7 cm flux was 92.3,
96.2, 96.5, 96.9, 99, 99.3, and 109.5, with a mean of 98.5.
Estimated planetary A indices were 7, 8, 3, 13, 8, 8, and 4, with a
mean of 7.3. Middle latitude A index was 6, 7, 1, 11, 5, 6, and 3,
with a mean of 5.6.


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