Propagation report 2/9/23

For this week’s ARRL Propagation Bulletin ARLP006:

A period of rising solar activity returned this week.

Ten new sunspot groups appeared this reporting week, February 2 – 8, 2023: two on February 3, one each on February 4 – 5, four more on February 6, and two more on February 8.

Early on February 9, Spaceweather.com reported a large emerging sunspot over the sun’s southeast horizon.

The average daily sunspot number for this week rose from 80.7 to 95.1, and the average daily solar flux from 139.5 to 155.9.

Geomagnetic indicators rose as well. The planetary A index rose from 7.9 to 11.7, and the middle latitude numbers rose from 5.9 to 7.6.

The rise in geomagnetic activity was related to solar wind late in the reporting week.

Predicted solar flux is 192 on February 9; 195 on February 10 – 13; 190 on February 14 – 15; 170 on February 16; 150 on February 17 – 18; 145, 140, 135, 130, and 135 on February 19 – 23; 130 on February 24 – 26; 125 on February 27; 130 on February 28 – March 3; 135, 150, and 160 on March 4 – 6; 155 on March 7 – 8; 160 on March 9, and 155 on March 10 – 12.

Predicted planetary A index is 12 on February 9 – 10; 5, 5, and 8 on February 11 – 13; 5 on February 14 – 17; 8 on February 18 – 19; 5 on February 20 – 21; 10 on February 22 – 24; 5, 5, and 8 on February 25 – 27; 5, 5, and 8 on February 28 – March 2; 5, 5, and 10 on March 3 – 5; 15, 15, 12, and 8 on March 6 – 9, and 5 on March 10 – 16.

Tamitha Skov’s latest, from February 5:

Sunspot numbers for February 2 through 8 were 56, 74, 66, 79, 139, 110, and 142, with a mean of 95.1. The 10.7-centimeter flux was 134.9, 134.5, 139, 144, 156.7, 184.7, and 197.6, with a mean of 155.9. Estimated planetary A indices were 6, 9, 6, 5, 18, 20, and 18, with a mean of 11.7. Middle latitude A index was 2, 6, 5, 3, 13, 12, and 12, with a mean of 7.6.