06/26/2020

No sunspots were observed since June 15, when the daily sunspot number was 11. This does not mean there were 11 sunspots seen, but instead it means that one sunspot group was observed containing one sunspot. The sunspot number is derived by assigning 10 points for each sunspot group, and one point for each sunspot. So, 11 is the minimum non-zero sunspot number.

On June 8, the daily sunspot number was 17, indicating 7 sunspots in one group.

If those seven sunspots had been in two groups, the sunspot number would be reported as 27.

Last week's bulletin ARLP025 reported average daily sunspot number of 7.9, and of course with no sunspots, this week that number dropped to zero.

Average daily solar flux declined from 70 to 67.7.

The sun has gone quiet again, as Spaceweather.com reported this week.

Geomagnetic indicators are still quiet, but the average planetary A index rose from 3.9 to 4.6 and the average middle latitude A index rose from 4.9 to 5.6. These values are insignificant.

Predicted solar flux for the next 45 days is 69 on June 26 through July 3, 70 on July 4-12, 68 on July 13-25, 70 on July 26 through August 8 and 68 on August 9.

Predicted planetary A index is 5 on June 26, 8 on June 27, 5 on June 28 through July 3, then 8, 5, 8 and 8 on July 4-7, 5 on July 8-30, then 8, 5, 8 and 8 again on July 31 through August 3, and 5 on August 4-9.

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Geomagnetic activity forecast for the period June 26 until July 22, 2020 from F.K. Janda, OK1HH.

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Geomagnetic field will be

quiet on: June 28, 30, July 1, (2,) 3, (6,) 9-11, 14-15, 18-20, 22

quiet to unsettled on: June 27, 29, July 4, 8, 12-13, 17, 21

quiet to active on: (June 26, July 5, 7, 16)

unsettled to active: nothing predicted

active to disturbed: nothing predicted

Solar wind will intensify on: June 26-27, (28-30,) July (4,) 5-8,

(9-10, 16-18, 22)

Parenthesis means lower probability of activity enhancement.

The predictability of changes remains lower as there are very few indications.

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A new video from Dr Tamitha Skov, WX6SWW: https://youtu.be/0bs3cHgBrVw[1]

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Phys.org has an article on inner workings of our Sun: https://phys.org/news/2020-06-motions-sun-reveal-sunspot.html[2]

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Here is a highly technical article on sunspots from Astronomy and Astrophysics: https://www.aanda.org/articles/aa/pdf/forth/aa37739-20.pdf[3]

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This weekend is ARRL Field Day, the most popular annual operating event. The 2020 Field Day has a rule waiver for this year allowing Class D stations operating from home and on commercial power to work each other. In the past they could only work all the other classes of stations.

Some operators don't realize that Field Day has only minimal logging requirements, just submit a list or dupe sheet for each band/mode showing the calls of the stations worked, and a summary sheet. There is no requirement to log the time of each contact, or even record the section or any report from stations you work. See the rules at: http://www.arrl.org/files/file/Field-Day/2020/1_61-2020%20Rules.pdf[4]

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For more information concerning radio propagation, see http://www.arrl.org/propagation[5] and the ARRL Technical Information Service at http://arrl.org/propagation-of-rf-signals[6]. For an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[7].

An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation[8]. More good information and tutorials on propagation are at http://k9la.us/[9].

Monthly propagation charts between four USA regions and twelve overseas locations are at http://arrl.org/propagation[10].

Instructions for starting or ending email distribution of ARRL bulletins are at http://arrl.org/bulletins[11].

Sunspot numbers for June 18 through 24, 2020 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 67.9, 68.8, 67.8, 67.6, 67.6, 67.1, and 66.9, with a mean of 67.7. Estimated planetary A indices were 4, 5, 6, 4, 4, 4, and 5, with a mean of 4.6. Middle latitude A index was 5, 7, 7, 4, 3, 6, and 7, with a mean of 5.6.

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[1] https://youtu.be/0bs3cHgBrVw
[2] https://phys.org/news/2020-06-motions-sun-reveal-sunspot.html
[3] https://www.aanda.org/articles/aa/pdf/forth/aa37739-20.pdf
[4] http://www.arrl.org/files/file/Field-Day/2020/1_61-2020%20Rules.pdf
[5] http://www.arrl.org/propagation
[6] http://arrl.org/propagation-of-rf-signals
[7] http://arrl.org/the-sun-the-earth-the-ionosphere
[8] http://arrl.org/w1aw-bulletins-archive-propagation
[9] http://k9la.us/
[10] http://arrl.org/propagation
[11] http://arrl.org/bulletins

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þ Synchronet þ Whiskey Lover's Amateur Radio BBS

07/03/2020

No sunspots this week. The pattern persists, and this surprises me. But Spaceweather.com reported a couple of weak, barely emerging spots, never numbered, and by their magnetic polarity were from new Cycle 25.

We rely on NOAA for official sunspot numbers, and the most recent one reported was 11 on June 15. See ftp://ftp.swpc.noaa.gov/pub/indices/DSD.txt[1].

Average daily solar flux over the recent reporting week (June 25 to July 1) averaged 68.6 up from 67.7 over the previous seven days. Average daily planetary A index was 4.7, the same as the average middle latitude A index.

Predicted solar flux over the next 45 days is 68, every day July 3 to August 16, which is hardly a promising outlook. Even with no sunspots, it would be nice to see solar flux values north of 70.

Predicted planetary A index is 5 on July 3-26, 8 on July 27-28, 5 on July 29 through August 1, 8 on August 2-3, and 5 on August 4-16.

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Geomagnetic activity forecast for the period July 3-29, 2020 from OK1HH.

Geomagnetic field will be

quiet on: July 3, 9-11, 14, 18-22

quiet to unsettled on: July 4, 8, 12-13, (15, 17,) 25-28

quiet to active on: (July 5-7, 16, 23-24, 29)

unsettled to active on: None!

active to disturbed: None!

Solar wind will intensify on: July (4,) 5-8, (9-10, 16-18, 21-22,) 23-25, (26-27)

Remarks:

- Parenthesis means lower probability of activity enhancement.

- The predictability of changes remains in the long run lower as there are very few indications.

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This video is quite dramatic and remarkable. An entire decade of continuous solar rotation images compressed into an hour: https://youtu.be/l3QQQu7QLoM[2]. Background: https://go.nasa.gov/2CXkw1k[3]

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Mike, KA3JAW, reported from Easton, PA urging everyone to monitor 29.6 MHz FM. He heard nothing on 10-meter FM over Field Day weekend. I will start doing this myself now with a new radio that covers that band/mode.

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An interesting article about solar plasma flow: https://www.inverse.com/science/solar-cycle-plasma-flow[4]

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Thanks to AA2F for catching errors in the A index averages appearing in the ARRL Letter (my fault), so I could correct them in this bulletin.

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For more information concerning radio propagation, see http://www.arrl.org/propagation[5] and the ARRL Technical Information Service at http://arrl.org/propagation-of-rf-signals[6]. For an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere[7].

An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation[8]. More good information and tutorials on propagation are at http://k9la.us/[9].

Monthly propagation charts between four USA regions and twelve overseas locations are at http://arrl.org/propagation[10].

Instructions for starting or ending email distribution of ARRL bulletins are at http://arrl.org/bulletins[11].

Sunspot numbers for June 25 through July 1, 2020 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 68.9, 67.8, 68.9, 69.2, 68.7, 68.1, and 68.9, with a mean of 68.6. Estimated planetary A indices were 3, 6, 7, 4, 3, 4, and 6, with a mean of 4.7. Middle latitude A index was 2, 6, 6, 4, 4, 5, and 6, with a mean of 4.7.

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[1] ftp://ftp.swpc.noaa.gov/pub/indices/DSD.txt
[2] https://youtu.be/l3QQQu7QLoM
[3] https://go.nasa.gov/2CXkw1k
[4] https://www.inverse.com/science/solar-cycle-plasma-flow
[5] http://www.arrl.org/propagation
[6] http://arrl.org/propagation-of-rf-signals
[7] http://arrl.org/the-sun-the-earth-the-ionosphere
[8] http://arrl.org/w1aw-bulletins-archive-propagation
[9] http://k9la.us/
[10] http://arrl.org/propagation
[11] http://arrl.org/bulletins

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þ Synchronet þ Whiskey Lover's Amateur Radio BBS