Solar report for 1-20-22

Tad Cook, K7RA, Seattle, reports: Solar and geomagnetic activity increased this week. The average daily sunspot number rose by 52 points, from 42.4 to 94.4. The sunspot number peaked at 120 last Saturday.

Average daily solar flux went from 101.6 to 112, peaking at 119.4 on Sunday. Average daily planetary A index rose from 6.1 to 15.6, and average middle latitude numbers went from 4.1 to 11.3.

As reported by Spaceweather.com, sunspot AR2929 erupted at 1744 UTC on January 18 with an M1.5 class solar flare, blasting a pulse of X-rays and causing a shortwave radio blackout. I observed the blackout while using FT8 on 10 meters to observe propagation using https://www.pskreporter.info/. Just before the blast I could see my 10 meter signal reported by stations on the East Coast, but suddenly I saw no reports. The surprising part was during that period no local stations could copy my signal either!

Predicted solar flux is 102, 98, 94 and 92 on January 20 – 23; 90 on January 24 – 26; 100 and 95 on January 27 – 28; 90 on January 29 – 30; 95 on January 31; 100 and 105 on February 1 – 2; 110 on February 3 – 10; 115 on February 11 – 14; 110, 108, and 106 on February 15 – 17; 102 on February 18 – 21; 100 on February 22 – 23; 95 on February 24, and 90 on February 25 – 26. Flux values may rise to 110 after March 2.

Predicted planetary A index is 16 on January 20; 8 on January 21 – 22; 12 on January 23; 8 on January 24 – 26; 5 on January 27; 10 on January 28 – 30; 5 on January 31 – February 3; then 15 and 10 on February 4 – 5; 5 on February 6 – 9; 12, 15, 12, 18, and 10 on February 10 – 14; 5 on February 15 – 19; 8 on February 20 – 22; 5 on February 23, and 10 on February 24 – 26.

Sunspot numbers for January 13 – 19 were 111, 112, 120, 103, 99, 59, and 57, with a mean of 94.4. The 10.7-centimeter flux was 105.5, 110.2, 115.6, 119.4, 113.5, 114.5, and 105.3, with a mean of 112. Estimated planetary A indices were 3, 15, 22, 19, 9, 18, and 23, with a mean of 15.6. Middle latitude A index was 3, 10, 17, 16, 6, 12, and 15, with a mean of 11.3.

A comprehensive K7RA Solar Update is posted Fridays on the ARRL website. For more information concerning radio propagation, visit the ARRL Technical Information Service, read “What the Numbers Mean…,” and check out the Propagation Page of Carl Luetzelschwab, K9LA

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

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