(C) ARRL Letter
This story was originally published by ARRL Letter and is unaltered.
. . . . . . . . . .



The K7RA Solar Update [1]

[]

Date: 2023-07

Space Weather News sent this alert on June 29:



"BIG SUNSPOT ALERT: One of the biggest sunspots in years is directly

facing Earth. AR3354 is 10 times wider than Earth and about 1/3rd

the size of the historical Carrington sunspot. It's so big,

observers in Europe and North America are seeing it naked eye

through the smoke of Canadian wildfires. Earth-directed flares are

likely in the days ahead."



See spaceweather.com for continuing coverage.



Conditions were favorable over the Field Day weekend, with the

exception of a brief period when the planetary K index rose to 5 on

Saturday night. This is mentioned in the commentary by OK1HH which

follows.



There were five new sunspot groups on June 23, two more on June 24,

another on June 26 and another on June 27.



Average daily sunspot numbers were up, and solar flux was down.



Average daily sunspot number rose from 143 to 170, and average daily

solar flux declined slightly from 165.4 to 160.3.



This is unexpected, because we normally see these values track

together.



Predicted solar flux is 150 on June 30 through July 5, 155 on July

6, 135 on July 7-8, then 145, 155, 160, 165 and 170 on July 9-13,

175 on July 14-18, 170 on July 19-21, then 160, 150, 145, 145, 140

and 135 on July 22-27, then 130 on July 28 through August 1, 135 on

August 2-4, then 145, 155, and 165 on August 5-7. Flux values may

continue to rise to a peak of 175 before mid-August.



Predicted planetary A index is 8, 15 and 10 on June 30 through July

2, 5 on July 3-7, 12 and 8 on July 8-9, 5 on July 10-11, then a

stormy 20 and 30 on July 12-13, 8 on July 14-23, 12 on July 24-25, 8

on July 26-27, 12 on July 28-29, 8 on July 30, 5 on July 31 through

August 3, 12 and 8 on August 4-5, 5 on August 6-7, then 20 and 30

again on August 8-9. Note that recurring stormy conditions are

predicted at one solar rotation, which is about 27.5 days, following

the July 12-13 prediction.



The above predictions are from forecasters Thompson and Kiser at the

USAF space weather group.



Weekly Commentary on the Sun, the Magnetosphere, and the Earth's

Ionosphere June 30 to July 06, 2023 from F.K. Janda OK1HH.



"In the solar X-ray field during June we could observe the most

significant solar flare so far: X1 in the active region AR3341. It

happened on June 20 at 1709 UTC near the southeastern limb of the

solar disk. In the region where the Sun was high, it caused the

Dellinger Effect, https://bit.ly/3NA61kT .



"The same sunspot group was also the source of the M4.8 flare two

days later. It ejected a CME, but not toward Earth.



"Nevertheless, its passage close to Earth probably caused an

increase in geomagnetic activity on the evening of 24 June.

Theoretically, it could also have been a CME from the X1 eruption of

20 June.



"On June 26, we were surprised by sunspot group AR3354 just above

the solar equator and east of the central meridian. It did not exist

the day prior. Over the next two days its area grew to ten times the

size of the Earth, making it easily observable by the naked eye.



"Significantly, its magnetic configuration changed to

beta-gamma-delta, which is enough energy for powerful solar flares.



"The geomagnetic field has been quiet to unsettled so far.



"AR3354 will be pointed directly toward Earth in the next few days,

so it looks like the next disturbance could begin on July 1. And of

course, a possible large flare could cause a Dellinger Effect

throughout the whole HF spectrum."



Pat, W5THT wrote:



"I have been an active ham since 1956 and on the Mississippi coast

since 1971. This year has strengthened my belief in an old

observation.



"There is/was a dome of high pressure that moved from over Texas to

now over me. Before it moved east, I was able to take part in the 6

meter propagation to Europe.



"Since it moved over me, the DX Maps page shows a gap in the DX

propagation from northern Florida to central Louisiana. This is not

the first time I have seen it happen, but the new generation of TV

weather persons presented a picture of the dome of high pressure

that coincided with my propagation observations. Suspicions

confirmed?



"Years ago, on 2 meters I noticed that propagation followed weather

fronts up the east coast. Thanks for reading this and perhaps

someone younger than me has already done the research."



Jon Jones, N0JK wrote:



"Wow -- a surprise opening on 6 meter FT8 to Brazil June 25!



"A CME impact at 1900 UTC may have boosted the TEP MUF Sunday

afternoon. That and some help with sporadic-E -- opening to Brazil

on 6 meters from North America during the summer.



"Had been out with our dog. Saw WQ0P PSK flags for PY2XB. Turned on

radio at home with dipole. PY2XB was loud. Really loud. Also copied

PY5CC. He spotted me as well, but no QSO. PY2XB in for almost half

an hour. Like a pipeline. Saw him work a few 5s and 0s. KC0CF worked

CE2SV. With higher solar activity, the TEP zone still works even in

our summer. This mode works for D2UY (Angola), 3B9FR (Rodrigues

Island in Indian Ocean), and ZL."



An article on Solar Cycle 25 peak and nice images:



https://bit.ly/3ps6iOI



Understanding Space Weather: A Glossary of Terms:



https://bit.ly/3XuimeQ



"Astro Bob" on that big sunspot:



https://bit.ly/46rC3YU



Frequent contributor David Moore shared this fascinating article

comparing the current big sunspot with the one that launched the

infamous Carrington Event 164 years ago.



https://bit.ly/3CUGZYC



Another Solar Cycle article:



https://bit.ly/3XvIk1y



Yet another Carrington Event article:



https://bit.ly/3XuSe3o



Article about Solar max:



https://bit.ly/44jM5tP



A Houston Chronicle article on solar max:



https://bit.ly/445vtWf



Flares and how they are measured:



https://bit.ly/3prvtRs



A video from Dr. Tamitha Skov, WX6SWW, from last week:



https://www.youtube.com/watch?v=sfXz9nk6NDs



Send your tips, reports, observations, questions and comments to

[email protected]. 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 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 .



Also, check this article from September, 2002 QST:



https://www.arrl.org/files/file/Technology/tis/info/pdf/0209038.pdf



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 June 22 through 28, 2023 were 176, 194, 200,

180, 158, 141, and 141, with a mean of 170. 10.7 cm flux was 173.2,

169.7, 160.8, 154.8, 157.7, 151.2, and 154.9, with a mean of 160.3.

Estimated planetary A indices were 8, 9, 16, 15, 11, 8, and 8, with

a mean of 10.7. Middle latitude A index was 8, 9, 16, 10, 11, 7, and

8, with a mean of 9.9.





[END]
---
[1] Url: https://www.arrl.org/news/the-k7ra-solar-update-784

Published and (C) by ARRL Letter
Content appears here under this condition or license:  Permission of ARRL.

via Magical.Fish Gopher News Feeds:
gopher://magical.fish/1/feeds/news/arrl/letter/

You are viewing proxied material from magical.fish. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.