The K7RA Solar Update


Although higher early in the reporting week, the average daily sunspot numbers declined more than 4 points to 85.7, while the average of daily solar flux numbers were down 1.5 points to 101.6 when compared to the previous week, May 26-June 1. Sunspot numbers for June 2-8 were 118, 122, 116, 74, 67, 58 and 45, with a mean of 85.7. The 10.7 cm flux was 111.6, 107.1, 102.8, 102.9, 100.2, 96.4 and 90.2, with a mean of 101.6. The estimated planetary A indices were 8, 4, 15, 27, 7, 9 and 14, with a mean of 12. The estimated mid-latitude A indices were 6, 3, 11, 20, 5, 8 and 9, with a mean of 8.9.

The predicted solar flux for the near term is 88 on June 10-13, then 86, 84, 84, 88, 95 on June 14-18, then 92 on June 19-21, 95, then 100 on June 22-23 and 110 on June 24-26. The solar flux then rises to a peak of 115 on June 28. The predicted planetary A index is 25, 12, 8 and 8 on June 10-13, then 5 on June 14-22, then peaks at 15 on June 24-25. Geophysical Institute Prague predicts unsettled to active conditions June 10, unsettled June 11, quiet to unsettled June 12-13, unsettled June 14, quiet to unsettled June 15 and quiet conditions June 16.

On June 3, there were eight sunspot groups facing Earth, numbered consecutively 1225-1232. Then on June 5, groups 1225, 1229, 1230 and 1231 disappeared and new group 1233 emerged. On June 7, 1233 disappeared and on June 9, 1226 left us and new group 1234 appeared.

Scott Bidstrup, TI3/W7RI, sent a link to some fantastic HD videos of solar eruptions.

If you check here on page 14 and compare it with page 15 here, you can see that some reported and predicted smoothed sunspot numbers have changed over the last month. The smoothed sunspot numbers for December 2010-November 2011 have each gone down 1 or 2 points. The numbers are smoothed over a year, so the current month would average actual data that has already been measured for about the past six months, with about six months of data predicted into the future.

Bob Cashdollar, NR8U, of Newark, Ohio reports: “On June 4 at 0208, I checked 10 meters for activity for the 10-X Open Season Contest. When I fired up the rig and computer, I landed right on ZL3TE working another ZL on PSK31 on 28.120. He was very strong and I watched the QSO on the waterfall. When he finished with the ZL QSO, I called him and to my surprise, he came right back and we exchanged info. I thought this contest was going to be really easy. Boy, was I mistaken! I had a lot of trouble seeing and working anybody stateside. I checked the band this morning (June 4) around 1400 and most stations were not workable, with a lot of scattering of the other stations transmissions. Maybe I should go up to Bob, W3HKK, who you mentioned in your last column -- he just lives about 25 miles northwest of me. Maybe he has better propagation!”

Jon Jones, N0JK, of Kansas reports: “I worked Dave, VP5/W5CW, on 6 meter SSB on June 1 at 0018. Dave worked many across the mid-USA on double hop E-skip the afternoon of May 31. I was operating portable using a 2 el Yagi.”

Charlie Calhoun, K5TTT, of Owasso, Oklahoma (EM26ch), wrote: “I had something unexpected happen during the E-skip openings this week on 6 meters. On two consecutive days, I worked two different stations in totally different directions, less than 24 hours from exactly one year prior. On June 1, 2010, I worked XE2NS, DL95 at 0247, then on June 1, 2011, I worked Alfonso again at 0323. I thought that was pretty neat until the next day when I worked K0PP in grid square DN36 at 0322 and noticed him in my log from 0305 on June 3, 2010.”

Last week’s bulletin contained a message from Rudy Hanau, K2EVY, of Rye Brook, New York, about some 20 meter backscatter propagation he experienced. The report didn’t mention this, but the propagation was observed around 0300 on May 29. I passed this on to Carl Luetzelschwab, K9LA, who had the following comments for Rudy.

Carl reported back:” I looked at the Boulder ionosonde data (kind of along your path to K6ZA) for a couple days before and after May 29. The data show a depletion (roughly 33 percent) of F2 region electrons on May 28 and May 29, undoubtedly due to the spike in the A index beginning on May 27 and continuing through May 30. I’m sure this would show up in other mid latitude ionosondes. This is likely the reason the “normal” path wasn’t there. Next, I looked at Pt Arguello (Vandenberg Air Force Base in Southern California) ionograms from 0215-0300 UTC on May 29. They show good sporadic E traces that could easily support 14 MHz. The Pt Arguello ionosonde is about 230 miles SSE of K6ZA, so it is as good an indicator as anything that Es was occurring in the vicinity of K6ZA. Thus, this cursory look says your unusual path might have been due to an Es cloud. Kind of makes sense since we’re in the Es season. And it might explain K6ZA’s follow-on QSO with the Nevada guy.”

Rudy responded: “I was not aware that sporadic E effects were noticeable all the way down to 20 meters”. Carl wrote back, saying he agreed that the “normal” refraction mechanism is likely out of the picture on 20 meters, “as the high sporadic E electron density is probably not thick enough vertically for refraction on 14 MHz. I wasn’t thinking refraction -- I should have been more explicit. I considered reflection and scatter from the sporadic E cloud. As for conductivity, the highest electron density seen in the Pt Arguello ionograms (8 MHz) translates to a conductivity of around .00025 S/m on 14 MHz. Poor ground has a conductivity of .002 S/m, so we’re an order of magnitude less than poor ground. Regardless, some reflection could occur on 20 meters.” Thanks, Carl!

And last, Bob Paglee -- who is probably either WA7CFP or KB2ITO (he didn’t say) -- of Moorestown, New Jersey, sent a note after reading our item in the May 27 edition of the Solar Update about the geophysical announcements on WWV ending, and thought WWV was being shut down, which it is not. Bob can rest easy -- WWV is not going away. The solar flux and geomagnetic indices that are updated every three hours and currently are broadcast via voice at 18 minutes after each hour are ending. The same reports will still be available on the Internet. You can find the text of the message currently read on WWV still online.

All times listed are UTC, unless otherwise noted.

Amateur solar observer Tad Cook, K7RA, of Seattle, Washington, provides this weekly report on solar conditions and propagation. This report also is available via W1AW every Friday, and an abbreviated version appears each Thursday in The ARRL Letter. You can find a guide to articles and programs concerning propagation here. Check here and here for a detailed explanation of the numbers used in this bulletin. An archive of past propagation bulletins can be found here. You can find monthly propagation charts between four USA regions and 12 overseas locations here. Readers may contact the author via e-mail.