Register Account

Login Help


The K7RA Solar Update


Solar activity was lower this week, although for the past few days, both the sunspot numbers and solar flux were rising. The average daily sunspot numbers declined more than 14.3 points to 116.1, while the average daily solar flux was off by 14.5 points to 115.9. There were five new sunspot groups this week: two each on June 9-10, and one more on June 13. Sunspot numbers for June 7-13 were 98, 90, 107, 127, 114, 132 and 145, with a mean of 116.1. The 10.7 cm flux was 128.2, 124.2, 128.3, 128.3, 133.9, 141.3 and 142.8, with a mean of 115.9. The estimated planetary A indices were 8, 8, 8, 6, 14, 13 and 6, with a mean of 9. The estimated mid-latitude A indices were 8, 9, 9, 6, 11, 10 and 7, with a mean of 8.6.

The latest prediction has solar flux at 150 on June 15-16, 145 on June 17-18, 140 on June 19-20, 130 and 120 on June 21-22, 110 on June 23-26, 105 on June 27-28, followed by a climb back to 120 on July 1-12. The predicted planetary A index is 5 on June 15-16, 18 on June 17, 8 on June 18, and 5 on June19-25. The next peak of geomagnetic activity is predicted for June 30-July 4, with the planetary A index at 8, 15, 12, 10 and 8. Following that is a similar peak on July 15-17 of 15, 12 and 8. Looking further out, the planetary A index of 8, 15 and 12 is predicted for July 27-29.

The geomagnetic forecast from OK1MGW has quiet to unsettled conditions June 15-17, quiet to active June 18, active June 19-20, quiet to unsettled June 21, mostly quiet June 22-23, quiet to unsettled June 24-29, quiet to active June 30 and active conditions July 1-3.

The most active days over the past week were June 11-12, when the planetary A index was 14 and 13. The high latitude college A index was 22 and 8 on those days, but the mid-latitude A index numbers from Fredericksburg, Virginia were only 11 and 10.

I often get messages about Solar Cycle 19, the huge solar cycle that peaked in 1959, but not so often about the peak of Solar Cycle 18. Lynn Coffelt, W7LTQ -- who lives on Fidalgo Island (IOTA NA-065) in the San Juan Archipelago and signs his messages “Old Chief Lynn” -- wrote: “Indeed Solar Cycle 19 was hot, and perhaps even hotter, judging by 10 meter operations, was Solar Cycle 18! There were a couple of weeks in the spring of 1948 when the 10 meter phone band was just one howling mess of heterodynes when AM was king. During Solar Cycle 19, I was working the Tucson local 10 meter ‘short skip’ net, when there were a couple of early evenings when stations across town in Tucson were working short skip and long path propagation simultaneously. That was a strange echo sounding mess. Turning our beams toward a short skip contact and 180 degrees away confirmed the phenomenon. I think we were probably on the so-called Grey Line.”

Yes, in the days before SSB phone, a pile of AM signals could sound quite messy. By the way, 1948 was the year W7LTQ turned 16 years old. You can have a look at Solar Cycles 18 and 19 and many others on the WM7D Historical Solar Charts. Solar Cycles 18 and 19 are the fifth and sixth cycle peaks from the left side of the page in the chart of “Monthly Sunspot Numbers 1900 to 1999.”

Regarding the link in last week’s bulletin to the researcher who believes modern sunspot numbers are inflated, Ken Grimm, K4XL, of Amherst, Virginia wrote: “Regardless of what Professor Svalgaard’s charts and tables show, those of us who lived through the late 50s and enjoyed the benefits of something that he thinks didn’t happen, know what we experienced. Nothing since has come even close to the conditions on the HF bands during those wonderful days. Fifty watts of AM on 10 meters was enough to work the world with honest 5×9 signals! Twenty meters was open 24 hours a day and DX was commonplace. Nothing can convince me that the late 50s weren't unusual!”

An interesting article in the popular press appeared this week, suggesting that long term prediction of solar cycles is impossibleAlso note toward the end of the article that the Bidya Binay Karak authored a paper explaining why sunspots disappeared for a time in 2008-2010. When I look at his curriculum vitae, I see a paper about the Maunder Minimum, but not about the more recent quiet Sun.

Don’t miss Carl Luetzelschwab’s interesting article in the current (July 2012) issue of QST, “Our Recent Solar Minimum and Sunspot Cycle 24 Progress.” You’ll find it on page 33. Phil Platt, of the Bad Astronomy blog, has a link to a video of an active sunspot, complete with dramatic music. Also check here for a piece on upcoming solar storms.

On June 12, Jeff Hartley, N8II, of Shepherdstown, West Virginia, reported: “Twelve meters has been open to unexpected areas on F2 and combination Es/F2 paths recently. On June 9 at 2317, I worked OM3EY with a S9 CW signal, followed by HL2WP S7 at 2321. CQs toward Europe and Asia didn’t result in any other contacts. Twelve meter activity is pretty low. Fifteen meters has been open all night to the west and northwest for European stations quite often lately. It was 0041 (0341 in Latvia) when Alex, YL3GAX, answered my CQ; he was S7. Nothing much was happening above 15 meters towards Europe on June 10 around 2000, but by 2052, I logged MD0CCE with 599 on 12 meters CW, followed by IZ2BHP and G0GKH on 10 CW. Then CQs on 10 SSB resulted in a run of about 20 European stations from 2112-2126, the most distant being SV2FLM and 9A6JOY. This was a good Es opening, with typical spotty coverage on the European end. Quite a few stations were running 100 W or less to verticals or low dipoles; they were typically S5 or less, but Q5 with bigger stations mostly S7. On June 11, I worked EA7JZ, peaking 59 on 10 meter SSB at 2225, but I didn’t hear any other European stations.”

James French, W8ISS, of Lincoln Park, Michigan, wrote to ask if there were any reports of unusual propagation during the recent transit of Venus event. I did not receive any, nor did I expect them. But James got a great response when he set up a public viewing of the recent transit. He wrote: “We had a great viewing of the transit here in Lincoln Park (EN82jg). I helped out at the high school’s observatory with the local astronomy club. About 400 turned out for the event, which was better than I really expected with no publicity, other than a sign out at the road.”

Steve Pulley of Stoughton, Wisconsin, sent in an SWL report after copying last week’s bulletin from W1AW using PSK-31 over a Radio Shack DX-392 general coverage shortwave receiver. Looks like perfect copy, using FLDigi, which he read about in an ARRL License Manual. He was excited, waiting for his ham license in the mail. I see that on the same day he wrote, he was issued KC9WDH.

I don’t know when we last had a look at this, but note the OVATION Auroral Forecast. They display a handy red line indicating the furthest south points where aurora might be visible after dark.

Thanks to Andy, N7TP who sent this amusing link.

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.



Instragram     Facebook     Twitter     YouTube     LinkedIn