Tad Cook, K7RA, of Seattle, Washington, reports for this week’s ARRL Propagation Bulletin:
Solar activity increased over this reporting week, July 14 – 20, with average daily sunspot number rising from 102.1 to 137.3, and average daily solar flux from 147.4 to 157.6.
Peak sunspot number was 166 on July 17, and peak solar flux was
171.4 on July 15.
Geomagnetic activity peaked on July 19 when planetary A index was 26 and middle latitude A index at 19. Alaska’s high-latitude college A index was 43, with the K index at 6, 5, 5, 6, and 5 at 0900 – 2000 UTC.
Average daily planetary A index decreased this week from 12.4 to 9.4.
A crack opened in the Earth’s magnetic field on July 19, allowing solar wind to stream in. It is documented at
https://www.spaceweather.com/images2022/19jul22/data.jpg
At 2241 UTC on July 20, the Australian Space Forecast Centre issued a geomagnetic warning. “An increase in geomagnetic activity is expected over 22 – 24 July due to the onset of coronal hole high speed wind streams.”
Here is the latest forecast from the United States Air Force (USAF). Predicted solar flux seems promising with flux values peaking around 160 on July 30 through August 7 and again from August 26 through early September.
Predicted flux values are 130 on July 21 – 22, then 120, 115, 110, 105, 100, 110, and 150 on July 23 – 29, then 160 on July 30 through August 7, then 155, 145, and 138 on August 8 – 10, then 138 on August 11 – 12, then 128 and 125 on August 13 -14, 130 on August 15 – 17, 135 on August 18 – 20, 138 and 148 on August 21 – 22, and 150 on August 23 – 25.
Predicted planetary A index is 22 on July 21 – 22, then 20, 12 and 8 on July 23 – 25, 5 on July 26 – 28, 8 on July 29 through August 2, then 12 and 10 on August 3 – 4, 8 on August 5 – 7, then 15, 28 and 12 on August 8 – 10, 8 on August 11 – 17, then 15, 20 and 12 on August 18 – 20, and 8 again on August 21 until the end of the month.
Here are weekly highlights and forecast from National Oceanic Atmospheric Administration (NOAA), dated July 17:
In Friday’s bulletin, look for details on 40 MHz activity among special experimental licensees, which I misidentified as 49 MHz in last week’s bulletin. There will also be 6-meter reports.
Send your tips, reports, observations, questions, and comments to k7ra@arrl.net.
Sunspot numbers for July 14 through 20, 2022 were 133, 141, 153, 166, 125, 114, and 129, with a mean of 137.3. 10.7 – centimeter flux was 169, 171.4, 176.2, 161.2, 149.4, 144.1, and 132.2, with a mean of 157.6. Estimated planetary A indices were 5, 8, 7, 5, 8, 26, and 7, with a mean of 9.4. Middle latitude A index was 5, 7, 9, 6, 10, 19, and 7, with a mean of 9.
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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