Tad Cook, K7RA, Seattle, reports: Sunspot activity was quite a bit lower this week, but new sunspot groups emerged on December 31, January 1, January 4, and January 5. Average daily sunspot number dropped from 110.1 to 36.4, while average daily solar flux went from 124 to 91.4.
Geomagnetic activity was still fairly quiet, even with a number of flares and CMEs, with average daily planetary A index changing from 6.4 to 7.7, and average middle latitude A index from 4.4 to 6.
Predicted solar flux over the next month shows 10.7-centimeter flux values peaking at 120 on January 16 – 24 and again at 120 in mid – February. The daily predicted values are 84 and 88 on January 6 – 7; 92 on January 8 – 12; 115 on January 13 – 15; 120 on January 16 – 24; 110 on January 25; 100 on January 26 – 27; 95 and 90 on January 28 – 29; 88 on January 30 – 31; 85 on February 1 – 5; 90, 95, and 100 on February 6 – 8, and 115 on February 9 – 11.
Predicted planetary A index is 5 on January 6 – 8; 12, 14, and 8 on January 9 – 11; 5 on January 12 – 14; 8 and 12 on January 15 – 16; back to 8 on January 17 – 18; 5 on January 19 – 22; 10 on January 23; 8 on January 24 – 26; 5 and 10 on January 27 – 28; 8 on January 29 – 30; 5 on January 31 – February 6; 10 on February 7 – 8, and 5 on February 9 – 10.
Sunspot numbers for December 30 – January 5 were 77, 53, 52, 25, 12, 12, and 24, with a mean of 36.4. The 10.7-centimeter flux was 102.4, 101.5, 93.9, 89, 84, 85.5, and 83.7, with a mean of 91.4. Estimated planetary A indices were 8, 4, 11, 10, 12, 6, and 3, with a mean of 7.7. Middle latitude A index was 7, 2, 9, 7, 9, 5, and 3, with a mean of 6.
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