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The K7RA Solar Update


Tad Cook, K7RA, Seattle, reports: Weak solar activity continues, with sunspots returning on May 4 – 14 before disappearing again. From the May 3 – 9 reporting week, the average daily sunspot number declined from 14.6 to 6.4 while the average daily solar flux increased from 68.3 to 70.2.

Earlier in the week geomagnetic indicators showed unrest from a solar wind stream. Average daily planetary A index declined to 8.4 this recent reporting week, compared to 15.1 over the previous 7. The mid-latitude A index declined from 11.7 to 9.

Predicted solar flux is 69 on May 18-20; 68 on May 21-25; 70 on May 26-29; 68 on May 30 – June 2; 70 on June 3-8; 71 on June 9-14; 70 on June 15-25; 68 on June 26-29, and 70 on June 30 – July 1.

Based on this forecast, sunspots may return on May 26 or June 9. May 26 is when the solar flux is expected to rise to 70 before declining again, then hitting 71 on June 9.

Predicted planetary A index is 14 and 8 on May 18-19; 5 on May 20-31; 18 and 28 on June 1-2; 16 on June 3-4; 14, 12, and 8 on June 5-7; 5 on June 8-12; 18, 15, and 10 on June 13-15; 5 on June 16-27; 18 and 28 on June 28-29, and 16 on June 30 – July 1.

In his geomagnetic activity forecast for the period May 18-June 12, F.K. Janda, OK1HH, writes that the geomagnetic field will be:

Quiet on May 27-29, June 8-9

Quiet to unsettled on 24, 30, June 7, 10-12

Quiet to active on May 19-23, 25, 31, 6

Unsettled to active on May 26, June 3-5

Active to disturbed on May 18, June 1-2

Solar wind will intensify on May (18-20, 25-27, 31,) June 1-3, (4-8)

Notes: Parenthesis means lower probability of activity enhancement; forecasts remain less reliable

From Tamitha Skov:

“Dear Tad, I have to share with you something important. As you likely know, I have been working with the American Meteorological Society to create a professional Space Weather certification. Such a certification will cement this emerging field by giving weather broadcasters the tools they need to bring Space Weather into our living rooms. Over the past week, we have taken a big step forward in this endeavor. The committee I am leading is now being officially asked to help Universities offer the specialized training that will most benefit weather broadcasters and the public.

“This couldn’t come at a better time. Today, as I look on Space News, I see yet another billionaire investing $32 million in deep space communications networks for the commercial space industry. Just like the dot-com boom at the turn of the century, more and more angel investors are seeing the future of asteroid mining and space tourism as having the potential to be extremely lucrative. But what they don’t yet know is how important Space Weather will be to their very livelihoods.

“We may be dealing with a quiet Sun this week, but the Space Weather remains busy. This is why it’s so important we have Space Weather forecasts. In this week’s video, I go over the short blast of fast solar wind that could bump us back into active conditions over the next day or two. Aurora photographers will need to stay on their toes! The Sun also keeps Amateur Radio operators happy as a new bright region rotates into Earth’s view. This region has boosted the solar flux and will keep radio propagation at marginal levels on the Earth’s day side easily over the next three days. That sure is a lot of activity for a spotless Sun!

“Cheers, Tamitha”

David Greer, N4KZ of Frankfort, Kentucky, offers excellent commentary regarding activity on seemingly dead bands:

“I know many hams find the current state of HF propagation to be depressing — particularly on the higher bands. But I take an opposite view. Often, I am pleasantly surprised by the SSB contacts I can make on bands that sound dead — but are not always as bleak as they first seem.

“I like to work phone on 17 meters and higher. Many afternoons when I get home from work a little after 2100 UTC, the higher bands sound dead. But I use a pre-recorded 30-second CQ I recorded on my Icom IC-7300’s SD card to make some noise. And often I get answers. But, if I don’t, I keep hitting the play button and let the rig call CQ and save my voice. I rotate my beam around to the various headings and sometimes I get at least one unexpected surprise.

“On several recent afternoons, when I heard no signals on 17 meters I have experienced openings from my central Kentucky QTH to Portugal, Spain or France between 2100 and 2200 UTC. And signals are often strong — S-9 plus. A recent 45-minute long QSO with F5RAG on 17 meters in the late afternoon produced SSB signals so strong it seemed as if we were talking across town on 2-meter FM simplex. A number of stations from Portugal and Spain have found their way into my log recently. Most say the same thing: I’m the only stateside signal they’re hearing. As to whether that’s because of propagation favoring my part of the USA, or my being one of the few stations ‘silly’ enough to even try to make contacts under such adverse conditions or my hilltop QTH with sloping terrain, I don’t know. 

“But Western Europe isn’t the only place I’ve worked recently, Twice, H44MS, Bernard, in the Solomon Islands, has called in off the back of my log periodic when it was pointed toward Europe.

“I also have had some luck on ‘dead bands’ working into South America on 15 and 10 meters about the same time of day. I’m fairly sure TEP (transequatorial propagation) accounts for those QSOs. 

“I do have days in which I CQ repeatedly on 17, 15. and 10 meter SSB for an hour or more and come up empty handed. But, on at least half of the days, a DX station replies. And I don’t ignore 12 meters. It’s yielded the occasional QSO into VK or ZL on a ‘dead band.’

“I know the guys working the new FT8 mode are having some real success in QSOing on so-called dead bands via scatter propagation. I operated a bunch of JT65 and FT8 when the latter mode first became popular — their ability to dig out weak signals is impressive — but, I found myself bored with them and returned to my SSB and CW roots. 

“I encourage other ops to try the ‘dead bands,’ particularly from 2100 to 2200 UTC. You just never know until you try.”

Only a brief abstract is available, but this article might be interesting. The full-text PDF appears to be unavailable, at least at this time.

For more information concerning radio propagation, see the ARRL Technical Information Service at. Here is an explanation of the numbers used in this bulletin. An archive of past propagation bulletins is on the ARRL website. More good information and tutorials on propagation are on the website of Carl, K9LA. The ARRL website also offers monthly propagation charts between four US regions and 12 overseas locations.

Instructions for starting or ending e-mail distribution of ARRL bulletins.

Sunspot numbers for May 10 – 16 were 11, 11, 12, 11, 0, 0, and 0, with a mean of 6.4. The 10.7-centimeter flux was 69.6, 70.3, 69.8, 70.9, 70.3, 70.3, and 69.9, with a mean of 70.2. Estimated planetary A indices were 12, 16, 10, 8, 5, 4, and 4, with a mean of 8.4. Estimated mid-latitude A indices were 11, 19, 10, 10, 5, 5, and 3, with a mean of 9.



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