mercoledì 8 Dicembre 2021
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The K7RA Solar Update

Tad Cook, K7RA, Seattle, reports: Weak solar activity persists, but Friday, August 13, was the sole spotless day in the current August 12-18 reporting week. Last week we reported 4 days with no sunspots in the previous 7 days. Average daily sunspot number increased from 9.9 last week to 17.7 during this week. Solar flux was the same, with the average inching from 73.7 to 73.8.

Geomagnetic indicators were also stable. Average planetary A index was 6.1, compared to 6.3 last week. Average middle latitude A index moved from 7.6 to 7.

Predicted solar flux is 75 on August 20; 73 on August 21 – 23; 72 on August 24 – 26; 73 on August 27 – 29; 74 on August 30 – September 1; 73 on September 2 – 11; 74 on September 12; 73 on September 13 – 17; 72 on September 18, and 73 on September 19 – 25.

Predicted planetary A index is 5 on August 20; then 8, 8, 10, 14, 12, and 8 on August 21 – 26; 5 on August 27 – September 1; 8 and 12 on September 2 – 3; 5 on September 4 – 10; 8 on September 11 – 13; 5 on September 14 – 18; 8, 12, and 8 on September 19 – 21, and 5 on September 22 – 28.

On August 14 Spaceweather.com reported that there were no sunspots, and that so far in 2021 there have been 56 days with no spots. “That might sound like a lot, but it is in fact a sharp reduction from hundreds of spotless days observed in 2019 and 2020,” Spaceweather.com observed. “Despite today’s blank sun, solar activity is intensifying compared to previous years.”

Here’s the geomagnetic activity forecast for August 20 – September 14 from J.K. Janda, OK1HH. He reports that the geomagnetic field will be:

quiet on August 20 – 21, 28, September 1, 5, 10, 14
quiet to unsettled on August 22, 25 – 27, 31, September 2, 4, 6 – 9
quiet to active on August 30, September 3, (11 – 13)
unsettled to active August (23 – 24, 29)
active to disturbed: Nothing predicted

Remarks:

– Parenthesis means lower probability of activity enhancement.

– The predictability of changes is very low because there are not enough indications.

Ken Brown, N4SO, reported hearing a new 10-meter beacon, N5TIT/b on 28.209 MHz. Signal was weak, and the path was 520 miles.

I’ve noted that the relatively low solar activity has depressed 10-meter signals, and my practice of using remote SDR receivers to hunt for beacons turns up little activity lately.

At the end of July, I spent 8 days in hospital for neurosurgery and managed to use kiwisdr.com/public/ to hunt for 10-meter beacons. I used the list at https://www.qsl.net/wj5o/bcn.htm to help identify them, and sent reports to the beacon owners.

Here’s the latest from Tamitha Skov, WX6SWW, the Space Weather Woman.

Sunspot numbers for August 12 – 18 were 11, 0, 47, 23, 14, 13, and 16, with a mean of 17.7. The 10.7-centimeter flux was 73.6, 72.9, 72.6, 74.6, 74.4, 73.1, and 75.3, with a mean of 73.8. Estimated planetary A indices were 4, 6, 5, 10, 7, 5, and 6, with a mean of 6.1 Middle latitude A index was 6, 9, 4, 13, 8, 7, and 6, with a mean of 7.6.

For more information concerning radio propagation, visit the ARRL Technical Information Service, read “What the Numbers Mean…,” and check out this propagation page.

A propagation bulletin archive is available. For customizable propagation charts, visit the VOACAP Online for Ham Radio website.

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