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The K7RA Solar Update


Tad Cook, K7RA, Seattle, reports: Sunspot activity persisted this week, although the numbers were a little lower. The average daily sunspot number declined from 124.4 to 110.1. Average daily solar flux slipped slightly, from 125 to 124. Average daily planetary A index went from 9.1 to 6.4, and average middle latitude numbers changed from 6.4 to 4.4.

New sunspot groups appeared on December 25, 26, and 28.

Solar flux over the next month is expected to peak at 130 on January 18 – 19, and the numbers are 100 on December 31 – January 1 – 2; 98, 95, and 95 on January 3 – 5; then 90, 92, and 100 on January 6 – 8; 105 and 110 on January 9 – 10; 115 on January 11 – 13; 118 on January 14 – 15; then 122 and 128 on January 16 – 17; 130 on January 18 – 19; 128, 125, and 120 on January 20 – 22; 125 on January 23 – 24; 122 on January 25; 120 on January 26 – 27; 115, 110, 100, and 95 on January 28 – 31; 90 on February 1 – 2; 92 and 100 on February 3 – 4; 105 and 110 on February 5 – 6, and 115 on February 7 – 9.

Predicted planetary A index is 8, 5, 12 and 8 on December 31 – January 3; 5 on January 4 – 10; 10 on January 11 – 12; 5 on January 13 – 14; 8 and 12 on January 15 – 16; 8 on January 17 – 18; 5 on January 19 – 22; 8, 10, 8, and 8 on January 23 – 26; then 5 on January 27 – February 6, and 8 on February 7 – 8.

JK Janda, OK1HH, offers his weekly commentary on the sun, the magnetosphere, and Earth’s ionosphere for December 30, 2021. (A continuation of Earth’s magnetic field activity predictions, published between 1978 – 2021.)

Solar activity was a little more vivid than we expected. Both spot and flare activity predominated in the Southern Hemisphere, while small coronal holes were observed mostly in the Northern Hemisphere.

This corresponded with irregular occurrences of the slightly increased activity of the Earth’s magnetic field and irregularities in the daily course of the ionosphere parameters.

The surprise came after the increase in proton density in the solar wind in the evening of December 29, where only a relatively small increase in its group velocity was observed. The result in the ionosphere was higher critical frequencies in the F2 layer in the middle of the night, and an increased occurrence of scattering and extended reflections, especially on the morning of December 30.

Mike, KM0T, in northwestern Iowa (EM13) wrote early on December 29 about 6 meters:

“Watching for a few days, and they predicted a few M-class flares hitting, but they seemed to have missed us. But I also noticed that the flux was around 140, and, knowing that a slight disturbance could skew things the right way, I was somewhat aware of things.

“Then I saw TEP-chordal stuff happening on December 26 to ZL/VK, which did not really surprise me thinking we may have gotten a few glancing blows from the flares. However, I did not see many if any midwest reports, so I sort of ignored it.

“The next day I saw it again, but was busy. Then, I saw an email from W7XU (Arliss in South Dakota) saying ZL was in. Sure enough. I turned the radio on and got decodes from ZL7DX. It appeared that there was an Es link in the midwest to DM43/XE area that was getting into the TEP-Chordal hops. I believe ZL7 was working a few XEs on FT8. So, I found one decode and moved my TX frequency up and started calling –17 report. He came back a few minutes later with –20, and then my RR73 was answered 73 in same sequence. It all happened very quickly. Then he was gone!

“Thought it was my first ZL, then I found out it was ZL7.

“Not sure anyone this far north and east worked him. The stacked six-element 6-meter Yagis were as low as possible, due to recent wind storms. Bottom one is about 24 feet, then about 20 feet higher on the mast for the upper one. 1.5 kW, no preamp, FLEX-6600.”

Related to this, see this article by Carl, K9LA.

Grant, KZ1W wrote on the Western Washington DX Club email list on December 29:

“N6MZ and I were separately working EU stations a couple of weeks ago on 12 meters well before local sunrise. Clearly, the short path wasn’t open, and we were mystified how that can happen.

“This week I am working EU on 15 well before sunrise.

“Both bands are very limited on short path with sunrise here and sunset in EU so close together at this time of year.

“I found a possible explanation in K9LA’s Propagation book: When US amateurs point antennas at Central Africa toward the magnetic equator, the higher level of ionization there often causes signals to be scattered. If EU points south to SW, a portion of their signals will be side-scattered west. The path is optimized roughly between 1200 and 1500 UTC, and seeking the best azimuth is worth trying. Should work on 10 meters, if EU is there.

“With QRO, a beam, and FT8, there is enough gain to make it work. Try it if the 40-meter FT8 mess is too annoying. But I did work A71AE Qatar on long path on 40 this week for a new band and a Marathon count.

I’ve used NE-aimed scattering paths on 10 meters open to the Caribbean, but not to EU. Different mechanisms I think. Learn something new all the time.”

AG7N responded:

“20 has been excellent to EU about 8 – 9 AM local. I’ve been working my good friend DF9LJ, who lives close to the Danish border, on CW and SSB at 599/59 the last few days. The band closes about 9:15 AM local. On 40, EU has been coming in at 7:30 AM local (1530 UTC) but I’ve been receiving the signals LP and SP simultaneously, which makes copy difficult at moderate CW speeds.”

W0PB wrote:

“On December 19 between 2032 and 2035 UTC on 10 meter CW, I worked Tord, SM3EVR, and Per, SM2LIY, in that order. Both were 579 – 589 here in West Des Moines, Iowa. They both gave me a 559 report from my 100 W and ground-mounted vertical. They disappeared 10 minutes later.”

N0JK wrote:

“Some sporadic-E December 26 from Kansas to N5BO (EM60) Florida. He received me on 50.313 MHz FT8 at –21 dB. Stations along the Gulf Coast and Texas worked New Zealand on 6 meter FT8 with Es links to TEP.”

Jeff, N8II, wrote from West Virginia on December 30:

“I worked MI0SAI and EI9HX with S-9 signals on 12 meters SSB at about 1545 UTC today. VE2CSI in CQ zone 2 (NE QC) was S-9 + 25 dB on 10 meters CW via Es at the same time. The DXMaps MUF was above 30 MHz in almost all directions from FM19 at 1700 UTC, but I only worked one station in San Jacinto County, Texas, plus Reno, Nevada, on either F2 or double hop Es.

“Sunday through Wednesday I worked EU on 10 meters,, with Tuesday being the best day. Two stations in Scotland were S-9 at around 1400 UTC Tuesday. They included Ian, MM0TFU, who always seems to be there when band is open. He now runs 400 W to a five-element Yagi.

“Also, I worked MI0SAI and an OE6 on 20 meters SSB at 2130 UTC Wednesday about 25 minutes before my sunset and many hours past EU sunset with possible Es aid.”

Don’t forget Straight Key Night tonight and tomorrow (January 1 UTC). I will be using keys from the estate of Vern Buttenob, K7AYE, who administered my Novice license exam when I was 12 years old.

Kids Day takes place on New Year's Day.

Sunspot numbers for December 23 – 29 were 143, 145, 117, 95, 85, 107, and 79, with a mean of 110.1. The 10.7-centimeter flux was 129.8, 126.2, 130.7, 125.4, 123.9, 120.5, and 111.4, with a mean of 124. Estimated planetary A indices were 4, 5, 7, 3, 10, 9, and 7, with a mean of 6.4. Middle latitude A index was 2, 3, 5, 2, 8, 6, and 5, with a mean of 4.4.

For more information concerning radio propagation, visit the ARRL Technical Information Service, read “What the Numbers Mean…,” and check this propagation page by Carl Luetzelschwab, K9LA.

A propagation bulletin archive is available. For customizable propagation charts, visit the VOACAP Online for Ham Radio website.

Instructions for starting or ending email distribution of ARRL bulletins are on the ARRL website.

Share your reports and observations. 



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