Tad Cook, K7RA, of Seattle, Washington, reports for this week’s ARRL Propagation Bulletin:
Last week’s bulletin opened with “Wow!” I don’t know what to say about this week, except it is beyond “wow!”
This actually has me thinking about Cycle 19.
Average daily sunspot numbers rose from 135.9 to 173.4, while average solar flux went to 221.8 from 181.2.
From Spaceweather.com: “If sunspot production continues apace for the rest of January, the monthly sunspot number will reach a 20-year high.”
Average planetary A index increased from 6.7 to 13.9.
On January 15, 2023, planetary A index reached a peak of 30, a very high value indicating a geomagnetic storm. Conditions were stormy throughout the week due to flares and coronal mass ejections. On that day in Fairbanks, Alaska, the college A index was 53. There was a large polar cap absorption event.
Nine new sunspot groups appeared during this reporting week, January 12 – 18. One on January 12, four on January 13, two more on January 15, and two more, one each, on January 17 – 18.
Predicted solar flux is 220, 218, 215, 212, and 210 on January 19 – 23; 206 on January 24 – 25; 200 and 190 on January 26 – 27; 185 on January 28 – 29; 190 on January 30 through February 2; 195 and 200 on February 3 – 4; 205 on February 5 – 6; 210 on February 7 – 11, then a big jump to 235 and 230 on February 12 – 13; 225 on February 14 – 16; 220 on February 17, and 215 on February 18 – 19.
Predicted planetary A index is 16, 12, 16, 12 and 8 on January 19 -23; 5 on January 24 – 25; 8, 12, and 8 on January 26 – 28; 5 on January 29 – 31; 12 and 8 on February 1 – 2; 5 on February 3 – 6; 12, 12, 15, and 12 on February 7 – 10; 5 on February 11 – 13, then 8, 15, 10, and 7 on February 14 – 17.
Sunspots in the news:
In Friday’s bulletin, look for a report from KA3JAW about his recent experiences on 10 -meter FM.
Sunspot numbers January 12 – 18, 2023, were 151, 181, 170, 177, 186, 185, and 164, with a mean of 173.4. The 10.7-centimeter flux was 211.6, 208.5, 227.8, 234.3, 228.1, 221.7, and 220.3, with a mean of 221.8. Estimated planetary A indices were 9, 12, 11, 30, 14, 6, and 15, with a mean of 13.9. Middle latitude A index was 8, 10, 9, 17, 10, 5, and 11, with a mean of 10.
Send your tips, questions, or comments to k7ra@arrl.net.
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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