Tad Cook, K7RA, Seattle, reports: We watched an active sun this week. Geomagnetic indicators peaked on Saturday, March 5, when Alaska’s high latitude college A index reached 42.
Again this week, sunspots covered the sun each day. Average daily sunspot numbers rose from 44 to 87.4, and average daily solar flux went from 98.5 to 115.5. Geomagnetic indicators were also higher. Average daily planetary A index increased from 7.3 to 11.4.
Predicted solar flux is 115 and 114 on March 10 – 11; 112 on March 12 – 14; 110 on March 15 – 16; 99 on March 17; 100 on March 18 – 21; 101 and 103 on March 22 – 23; 104 on March 24 – 27; 110, 115, and 116 on March 28 – 30; 118 on March 31 – April 1; 120 on April 2; 116 on April 3 – 4; 115 and 112 on April 5 – 6; 110 on April 7 – 9, and 108, 102, 98 and 99 on April 10 – 13.
Predicted planetary A index is 12 on March 10 – 11; 5 on March 12 – 14; 8 on March 15 – 16; 5 and 8 on March 17 – 18; 12 on March 19 – 20; 15 on March 21; 7 on March 22 – 24; 5, 10, and 8 on March 25 – 27; 5 on March 28 – 29; 10, 12, 25, 20, and 10 on March 30 – April 3; 5 on April 4 – 6; 15, 20, and 12 on April 7 – 9, and 5 on April 10 – 13.
Sunspot numbers for March 3 – 9 were 92, 77, 95, 82, 84, 93, and 89, with a mean of 87.4. The 10.7-centimeter flux was 110.9, 113.1, 120.1, 115.7, 118.3, 115.3, and 114.8, with a mean of 115.5. Estimated planetary A indices were 5, 10, 27, 18, 9, 6, and 5, with a mean of 11.4. Middle latitude A index was 3, 7, 19, 13, 7, 5, and 4, with a mean of 8.3.
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