Subj : The K7RA Solar Update
To   : QST
From : ARRL de WD1CKS
Date : Fri Apr 07 2023 11:38 pm

04/07/2023

�Average solar flux and sunspot numbers were way down this week. Sunspot
numbers were down by half, from 112.6 last week to 53.4.� Average daily solar
flux declined from 156.1 to 132.5.�

Geomagnetic indicators were lower too.� Average daily planetary A index from
23.3 last week to 15 in this bulletin, and average daily middle latitude A
index from 13.7 to 11.7.

The April 1 middle latitude A index of 11 is my guess.� The middle latitude A
index for April 1 was not available.

Predicted solar flux is 140 on April 7 and 8, 135 on April 9 to 11, 140, 145
and 130 on on April 12 to 14, 130 on April 14, 135 on April 15 to 17, 140 on
April 18 to 20, 135 on April 21 to 23, then 130, 125 and 120 on April 24 to 26,
115 on April 27 to 29, 125 on April 30, 120 on May 1 and 2, 115 on May 3 and 4,
then 110 on May 5 to 7, and 115, 120, 125 and 130 on May 8 to 11, then 135 on
May 12 to 14, and 140 on May 15 to 17.

Predicted planetary A index is 5 on April 7 to 10, then 8, 8 and 5 on April 11
to 13, 8 on April 14 and 15, then 12, 10 and 15 on April 16 to 18, then 5, 20,
15 and 10 on April 19 to 22, 5 on April 23 to 25, then 15 and 18 on April 26
and 27, 15 on April 28 and 29, 8 on April 30, 10 on May 1 and 2, 8 on May 3,
then 5 on May 4 to 6, then 12, 10, 8 and 5 on May 7 to 10, 8 on May 11 and 12,
then 10, 12, 15, 5 and 20 on May 13 to 17.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere --
April 6, 2023 from F.K. Janda, OK1HH.

"On March 29, another solar flare of category X1.2 was observed.� It came from
the AR3256 sunspot group near the southwestern limb of the Sun.

This year, in just three months, we've already seen seven X-class flares, the
same as all of last year.� There are still about two years to go before the
cycle peak.

On the morning of March 31, a solar wind stream hit Earth, triggering a minor
G1-class geomagnetic storm.� A relatively quiet weekend followed.

Then new sunspot group AR3270 emerged in the southern part of the solar disk.�
It grew rapidly, its two dark cores, larger than Earth, indicating an unstable
magnetic field.� If they merge an eruption would likely follow.� It would
probably be a geoeffective eruption because the sunspot was directly opposite
the Earth.

After the AR3270 sunspot group dips behind the southwestern limb of the solar
disk this weekend, there should be a temporary drop in overall solar activity,
accompanied by a string of geomagnetically quieter days.

As the irregular occurrence of higher geomagnetic activity results in irregular
changes in shortwave propagation conditions, the subsequent evolution should be
more regular and predictable."

This video from Tamitha Skov came out right after last week's bulletin:

https://youtu.be/F8ERhLiOK88[1]

More sun fun: �

https://youtu.be/VWhhSWjDJtw[2] �

https://bit.ly/41aolq2[3] �

Don't worry: �

https://bit.ly/3zCtg74[4]

On April 5 from 1723 to 1746 UTC, Tom, WA1LBK in Fall River, Massachusetts
copied HC1MD/2 in Ecuador on 6 meter FT8.� Check HC1MD on QRZ.com for some
beautiful photos by Rick, NE8Z.

https://bit.ly/3zBm5wa[5] �

This weekend is the CW portion of the Japan International DX Contest.

See http://jidx.org/[6]

Send your tips, reports, observations, questions and comments to
[email protected][7] .� 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[8] and the ARRL Technical Information Service
at http://arrl.org/propagation-of-rf-signals[9] .� For an explanation of
numbers used in this bulletin, see
http://arrl.org/the-sun-the-earth-the-ionosphere[10] .

An archive of past propagation bulletins is at
http://arrl.org/w1aw-bulletins-archive-propagation[11] .� More good information
and tutorials on propagation are at http://k9la.us/[12] �

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

Sunspot numbers for March 30 through April 5, 2023 were 99, 61, 23, 54, 56, 44,
and 37, with a mean of 53.4.� 10.7 cm flux was 140.3, 129.3, 125.3, 126.9,
133.6, 135.7, and 136.6, with a mean of 132.5. Estimated planetary A indices
were 17, 21, 13, 15, 15, 13, and 11, with a mean of 15.� Middle latitude A
index was 11, 17, 11, 13, 11, 10, and 9, with a mean of 11.7.


[1] https://youtu.be/F8ERhLiOK88
[2] https://youtu.be/VWhhSWjDJtw
[3] https://bit.ly/41aolq2
[4] https://bit.ly/3zCtg74
[5] https://bit.ly/3zBm5wa
[6] http://jidx.org/
[7] mailto:[email protected]
[8] http://www.arrl.org/propagation
[9] http://arrl.org/propagation-of-rf-signals
[10] http://arrl.org/the-sun-the-earth-the-ionosphere
[11] http://arrl.org/w1aw-bulletins-archive-propagation
[12] http://k9la.us/

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� Synchronet � Whiskey Lover's Amateur Radio BBS

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