K7RA's Solar Report

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Last update: Friday, 30-Sep-2022 05:33:10 GMT

ARLP039 Propagation DE K7RA
ARRL Propagation Bulletin 39 ARLP039 From Tad Cook, K7RA
Seattle, Washington September 30, 2022
To all radio amateurs

Sunspot activity rose this reporting week, September 22-28, with average daily sunspot numbers increasing from 68 to 105.1. But solar flux? Not so much. Average daily solar flux rose from 134.3 to 138.4.

So the sunspot average rose 55 0x0p+0nd solar flux only 3%. I usually expect the numbers to track more closely.

New sunspots appeared on September 22 and 23, and one more on September 27. On Thursday night (September 29) NOAA reported the daily sunspot number at 56, little more than half the average for the previous seven days, 105.1.

Tuesday September 27 had lots of geomagnetic activity, with the planetary A index at 24 and middle latitude at 33. Spaceweather.com blamed an unexpected CME. They also report a huge sunspot beyond the sun's eastern horizon with a helioseismic image at https://bit.ly/3ftpTIN.

The Australian Space Weather Forecasting Centre issued a geomagnetic warning at 2146 UTC on September 28.

"Geomagnetic 27 day recurrence patterns indicate that G1 geomagnetic activity is likely during the interval 30-Sep to 02-Oct.


Predicted solar flux from the Thursday night forecast appears much more optimistic than the Wednesday numbers, which were in the ARRL Letter on Thursday.

Instead of 135 and 130 for the next few days, they are 148 on September 30, 146 on October 1-4, 140 on October 5-7, then 135, 130, 128 and 132 on October 8-11, then 136 on October 12-13, then 138, 140, 138 and 135 on October 14-17, then 132, 130, 128 and 125 on October 18-21, then 130, 140, 142 and 145 on October 22-25, and 140, 135, 130, 125, 128 and 130 on October 26-31, then 132 on November 1-3, and 135, 130 and 128 on November 4-6.

Planetary A index is predicted at 20, 60 and 40 on September 30 through October 2, then 20, 18, 16 on October 3-5, 12 on October 6-7, then 8 on October 8-14, 10 on October 15-16, 8 on October 17-19, 12 on October 20-21, 8 on October 22-23, 10 on October 24-25, 8 on October 26-27, then in a recurrent disturbance as sunspots rotate into the same position as weeks earlier, 25, 50, 30, 20, 12 and 10 on October 28 through November 2, and back to 8 on November 3-10.

Of course, a planetary A index of 50 or 60 is huge, indicating an expected major geomagnetic disturbance.

From OK1HH:

"Weekly Commentary on the Sun, the Magnetosphere, and the Earth'sIonosphere ' September 29, 2022

Free continuation of predictions of the Earth's magnetic field activity, published in the years 1978 - 2021.

The following text is very brief as I am traveling around Europe without a computer. I will add more next time.

An unexpected and unpredicted surprise was the rise of geomagnetic activity during the night of September 24-25.

Further developments did not take place according to assumptions. Which, by the way, is a precursor to the next increase in solar activity.

Nevertheless, I present a forecast of further disturbances: September 30 and especially October 1!


F.K. Janda, OK1HH'D

Wow, Frantislav manages to submit his report without a computer! IE2''ve never been to Europe (unfortunately), but I imagine him ducking into some sort of Internet kiosk to file his report.

Tamitha Skov, WX6SWW the Space Weather Woman, last weekend:


Solar research:


Newsweek is at it again:


I continue to see unusual propagation using FT8, such as my signal only being received in a narrow band 100-200 miles wide on the East Coast of North America.

You do not need to be an FT8 user to use it to check out the bands. Just go to the pskreporter map page at https://bit.ly/3y3w2SL and select the band you are interested in (they even have 11 meters!) and the default "Signals'D and "Sent/Received by'D and change "the callsign'D to "grid square'D, entering your own four-character grid (or one near you wit h a larger ham population) and in the "Using'D field select FT8.

Hit "Go!'D and you will see where stations in your area are being received, including signal levels.

You can enter your own call instead of the grid, and select "Country of Callsign'D, and you will see activity all over your nation. I find it interesting early in the day to use this on 10 meters, and what I usually see is activity all over the East Coast, and especially in the southeast U.S. but not here on the west coast.

But I know that the 10 meter openings will advance across the country with the movement of Earth relative to our sun.

Explore the "Display options'D link just to the rignt of the time listed in the "over the last'D field, and you can customize this tool. I like to select "Show time text in black always'D , "Show connecting lines always'D and "Show SNR'D.

The "Show logbook'D link is very useful, once you have done a search. Often I will use this, searching for the callsign of an FT8 station who has mysteriously disappeared after connecting to me. I can sort the entries by Time to find out if anyone has received her since I last saw her signal.

The default "over the last'D setting is 15 minutes, but when searching for a callsign you can vary the time over the past 24 hours.

Have fun!

Send your tips, reports, observations, questions and comments to k7ra@arrl.net.

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 September 22 through 28, 2022 were 99, 111, 128, 96, 120, 110, and 72, with a mean of 105.1. 10.7 cm flux was 136.7, 146.3, 146.5, 134.7, 135.1, 134.5, and 134.8, with a mean of 138.4. Estimated planetary A indices were 6, 12, 13, 7, 6, 24, and 5, with a mean of 10.4. Middle latitude A index was 5, 12, 10, 5, 5, 33, and 3, with a mean of 10.4. NNNN

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