Seven new sunspot groups emerged this past week, but overall solar activity has declined.
It’s great to see the sun covered in sunspots; see Spaceweather.com’s recent image of the sun at https://www.spaceweather.com/images2023/04oct23/hmi1898.gif.
You can change the /04oct23/ field in the above URL to view a solar image of any date. By loading images of consecutive dates, you can initiate an animation using the back and forward buttons on your browser.
We are currently enjoying improved HF propagation with the change of seasons after the autumnal equinox. This is particularly noticeable on 12 and 10 meters.
Read an optimistic news story about the current solar cycle at https://cdapress.com/news/2023/oct/02/were-strong-solar-cycle/, and another report at https://bit.ly/3RMPjT1.
One new sunspot group appeared on September 30, followed by three
| Solar disk image taken October 5, 2023. [Photo courtesy of NASA SDO/HMI] |
more on October 1, and then one each on October 2, 3, and 4.
The average daily sunspot number declined from 170.6 to 128.6, while the average daily solar flux went from 168.8 to 155.6.
Geomagnetic indicators were quieter. The average daily planetary A index went from 17 to 9.1, and the average daily middle latitude A index declined from 13.7 to 8.9.
The outlook for next month has the solar flux at 160 on October 5; 162 on October 6 – 8; 155 on October 9 – 10; 150 and 160 on October 11 – 12; 158 on October 13 – 14; 156 on October 15 – 17; 154 on October 18 – 20; 152 on October 21; 154 on October 22 – 23; 156 and 158 on October 24 – 25; 160 on October 26 – 28; 162 on October 29 – 31, and 164 on November 1 – 3.
If we use this forecast as a guide, we can predict the solar flux average for the next reporting week, October 5 – 11, to be 2.4 points higher than that of this week.
Predicted planetary A index is 12 on October 5 – 6; 15, 8, and 5 on October 7 – 9; 8 on October 10 – 11; 5 on October 12 – 21; 10 and 8 on October 22 – 23; 5 on October 24 – 28, and then 15, 12, 8, 15, and 8 on October 29 – November 2. Sunspot numbers for September 28 – October 4, 2023, were 109, 102, 106, 136, 146, 150, and 151, with a mean of 128.6. The 10.7-centimeter flux was 147.8, 155, 159.1, 161.1, 157.4, 153.7, and 155, with a mean of 155.6. Estimated planetary A indices were 6, 12, 10, 9, 9, 8, and 10, with a mean of 9.1. Middle latitude A index was 5, 13, 11, 9, 10, 6, and 8, with a mean of 8.9.
A propagation bulletin archive is available. For customizable propagation charts, visit the VOACAP Online for Ham Radio website. Share your reports and observations.