The K7RA Solar Update
Tad Cook, K7RA, Seattle, reports: I felt cheated this week when a much-anticipated sunspot appeared only briefly, and after 2 days was gone. Sunspot region AR2758 only appeared on March 8 – 9, with daily sunspot numbers of 13 and 12, respectively. Some new activity is visible over the solar horizon — a very active and bright spot, but this time in the sun’s northern hemisphere.
Average daily sunspot numbers for the week rose from zero to 3.6, while average daily solar flux barely increased, from 70 to 70.2. Average daily planetary A index declined from 6.7 to 4.4, and average middle latitude A index decreased from 4.6 to 3.6.
Predicted solar flux over the next 45 days is 71 on March 12 – 14; 70 on March 15 – 18; 72 on March 19 – 22; 70 on March 23 – April 4; 72 on April 5 – 18, and 70 on April 19 – 25.
Predicted planetary A index is 5 on March 12 – 18; 12 and 8 on March 19 – 20; 5 on March 21 – 26; 12 and 8 on March 27 – 28; 5 on March 29 – April 5; 10 and 8 on April 6 – 7; 5 on April 8 – 13; 8, 12, and 8 on April 14 – 16; 5 on April 17 – 22, and 12, 8, and 5 on April 23 – 25.
Sunspot numbers for March 5 – 11 were 0, 0, 0, 13, 12, 0, and 0, with a mean of 3.6. The 10.7-centimeter flux was 69.5, 70, 69.9, 70.2, 70.8, 70.8, and 70.5, with a mean of 70.2. Estimated planetary A indices were 4, 5, 5, 5, 5, 4, and 3, with a mean of 4.4. Middle latitude A index was 3, 4, 5, 3, 5, 3, and 2, with a mean of 3.6.
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 K9LA’s Propagation Page.
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