The K7RA Solar Update
Sunspot activity continued to drop until early this week: The average daily sunspot numbers were 26.3, down more than 58 points from last week’s numbers, while the average daily solar flux declined to 92.8, down over 33 points from last week’s average. The weekly sunspot number average has declined since the May 31-June 6 period, when it was 130.4, followed by 116.1 the next week, 84.6 the next and 26.3 this week. Sunspot numbers for June 21-27 were 13, 13, 13, 24, 14, 28 and 79, with a mean of 26.3. The 10.7 cm flux was 97.7, 88.4, 84, 85.3, 88.6, 99.2 and 106.3, with a mean of 92.8. The estimated planetary A indices were 3, 5, 4, 5, 9, 8 and 6, with a mean of 5.7. The estimated mid-latitude A indices were 3, 5, 4, 5, 5, 7 and 8, with a mean of 5.3.
In next week’s bulletin we will have the latest three month moving average of daily sunspot numbers -- for April, May and June -- and it looks like it will be higher than the previous three month average for March, April and May. Also, yesterday (June 28) was day number 180 for 2012, and sunspot numbers are running higher this year. The average sunspot number over those 180 days is 82.4. Previous years 2003-2011 had yearly sunspot number averages of 109.2, 68.6, 48.9, 26.1, 12.8, 4.7, 5.1, 25.5 and 29.9, so 82.4 is quite a jump.
In last week’s Solar Update, we reported the average daily sunspot number as 87, but it was really 84.6. This is because we reported what may have been a preliminary sunspot number of 46 for June 20, but the sunspot number for that date was 29.
Geomagnetic conditions over the past week were quiet. The average planetary A index was 5.7, down from 12.6 last week, 9 the week before and 13.4 the week before that. The quiet planetary A index for this week was exactly as it was on the week of May 24-30 -- 5.7 -- which also happened to be the mid-latitude A index for that period.
The latest prediction from USAF/NOAA shows geomagnetic activity peaking on June 30-July 3, probably from a coronal hole spewing solar wind. There is also a thirty-percent chance of M-class solar flares today. The predicted planetary A index for June 29-30 is 10 and 18, followed by 15 on July 1-3, 10 and 8 on July 4, 5 on July 5-7, 8 on July 8-9, 5 on July 10-25, and then 10, 18, 15, 15, 15 and 8 on July 26-31. This is an echo of the activity this week, based on the 27.5 day rotation of our Sun, relative to Earth. The predicted solar flux is 115 on June 29-30, 120 and 125 on July 1-2, 130 on July 3-5, 135 and 140 on July 6-7, 135 on July 8-9, 130 on July 10-11, 125 on July 12-13, then 120, 115, 110 and 105 on July 14-17. Solar flux may dip below 100 around July 19-28, but that is a long way out, and difficult to predict.
OK1MGW of the Czech Propagation Interest Group predicts quiet to unsettled geomagnetic conditions on June 29, quiet to active June 30, active July 1-3, quiet to unsettled July 4-7, quiet to active July 8-9, and mostly quiet on July 10-12.
Scott Woelm, WX0V, of Fridley, Minnesota, commented on the recent lack of sunspots, and thinks he may have discovered a correlation of some sort: “I have found the reason for the recent decline in sunspots! My dad, David Woelm, W0ELM, just got a new radio.” Good thinking! He also mentioned that he has some images of May’s eclipse and June’s Venus transit on his website.
Conditions were pretty good for 2012 ARRL Field Day last weekend, meaning there was some solar activity, and geomagnetic conditions were nice and quiet. Some past Field Days didn’t have it so good. If you click here, you can download planetary K and A indices all the way back to 1932; using the perpetual calendar, you can find the fourth full weekend in June for any year. The 1988 ARRL Field Day on June 25-26 looked particularly bad, and so did June 23-34, 1984. Either may have been the year I was out with the Western Washington DX Club, and a sudden ionospheric disturbance hit late Saturday morning, making all receivers appear dead. You can see by downloading the data for 1988 that the K index hit 4 and 5 on Saturday morning, then conditions recovered into the evening, only to have a repeat on Sunday morning, a double-whammy.
Bill Mader, K8TE, President of the Albuquerque DX Association, sent a report on the W5UR Field Day operation at Torrance County Park in Edgewood, New Mexico: “Conditions were generally very good for Field Day, with the exception of 6 and 10 meters. Our 10 meter CW station made just one contact and 6 meters made just 48 contacts, with the majority during an opening to California on Saturday evening. Propagation for both was disappointing compared with previous years. Fifteen and 20 meters made up the bulk of the SSB and three CW stations QSOs. We ran 20 well into the night and started again early in the morning. Our GOTA operators ran stations on both 20 and 15 for hours in a row. Forty meters was good and we used 75 and 80 meters to advantage after running out of new ones on 40. Overall, ‘Old Sol’ helped this year, rather than hindering us. Getting up dipoles from 45 to 60 feet high took advantage of good propagation, as did our A4S at 40 feet. We seldom had to ‘search and pounce,’ keeping our QSO rates up. Our last hour on 15 meters in the SSB tent produced 99 QSOs, thanks to all three components: good propagation, a good antenna and an excellent operator. We’re looking forward to 2013 after we clean the desert dust off everything. Our preliminary QSO estimate is 5100 and with lots of CW plus bonus points, 2012 may be our best scoring Field Day ever.”
Gabor Horvath, VE7JH, reported on the Cowichan Valley Amateur Radio Society operation (VE7CVA) from Duncan, British Columbia, on Vancouver Island: “Twenty meters was open until about midnight. We had a great run on 15 meters from 6-10 PM. Ten meters barely popped open, I think we made fewer than 10 QSOs. Forty meters seemed to be real good, with action starting at about 7 PM till dawn, but 80 meters did not produce much long distance stuff and was fairly quiet.”
Walt Aulenbacher, WA5AU, reported on the Hays/Caldwell Amateur Radio Club KE5LOT operation from San Marcos, Texas: “We found conditions on 15 meters to be very good (lots of contacts) and, of course, also on 20 meters, but 10 and 6 meters were not great. We made some contacts on 10 meters and 6 meters despite conditions.”
Jed Petrovich, AD7KG, of the Utah DX Association reported on the K7UM operation, just east of Fairview, Utah in the mountains at 9000 feet: “We operated three stations for the entire 24 hours. We only made two contacts on 10 meters. On Saturday, it didn’t appear there was much activity on 15 meters. We checked this with a P3 panadapter and our 15 meter station was getting few responses to his CQs. The bulk of our nearly 3400 contacts (including dupes) were on 20 and 40 meters, both CW and SSB. On Sunday morning, we were still working 20 and 40; however, I switched over to 15 CW just after 10 AM MDT and found a lot of activity. I had some good runs going for nearly two hours until the end of the event. One of the other stations was also working 15 SSB during the same time frame Sunday morning, but he didn’t do quite as well. Our logging program reported my run rates around 90 per hour, with the SSB station about 40 per hour. During the same time frame, the 20 meter phone op was going strong with run rates of more than 150 per hour. We did have dipole up about 60 feet for 80 meters, but the band seemed very noisy. Hence, very few contacts were made on 75 meter phone. All in all, propagation seemed fairly good. Last year for example, one of our phone ops made 160 contacts on 10 meters during the last two hours of the event. We periodically checked 10 meters, but didn't find much going on.”
Kevin Lahaie, K7ZS, of Hillsboro, Oregon wrote: “We had very interesting band conditions. In a word, 10 meters was a big zero, 20 meter paths were very atypical and just never really opened up like you would expect. But the big surprise was 15 meters. It was open to the East Coast at the opening bell, and it stayed open to the East Coast all day, until around 10 PM. A little north-south, but just an amazing, solid long skip that defied time of day! We made 950 contacts on that band, 200 more than 20 meters! Overall, I don't think propagation was very good, but the real anomaly to me was the solid and long endurance 15 meter opening to the East Coast. I will be curious if East Coast stations were able to work each other with the long skip.”
The Bosque County Amateur Radio Club, W5BCR, operated from Clifton, Texas. Danny Rymer, K5FDR, reports: “I believe this was my best Field Day ever. I made a contact in Maui, Hawaii and I was able to have the contact talk to a few Cub Scouts who came to see what Field Day was all about. You should have seen their eyes and the smiles on their faces when they realized they were actually talking to someone in Hawaii. A reporter took a few pictures for the local newspaper while the boys were talking to the contact in Hawaii. Other members of the W5BCR club made numerous contacts throughout the US and Canada, and several of the club members let the Cub Scouts talk to their contacts on the other end. Those contacts really made a big impression and made the Cub Scouts’ day. Conditions were very good here in Texas; as a club, we worked all of the legal frequencies that were allowed per the rules. Most of the contacts were made on 20 and 40 meters (not too surprising), as well as a few other bands. We made a contact in Germany during the late evening and Slovenia at 0621 UTC on 14.272. All in all, this Field Day was better than any Field Day that I have ever participated in with any club, and that goes even for my first Field Day.”
Six meters apparently didn’t produce results for Field Day, but Julio Medina, NP3CW, of San Juan, Puerto Rico (FK68wl) reported: “On June 21, I worked TI5KD at 2306, and HK4BKB at 2313 on 6 meters. On June 22, I worked ON4GG at 1353, F6GCP at 1309, PA2M and F6ARC at 1309, F8DBF and OE1WWA at 1710, FJ/W6JKV in St Barthelme at 1842 and WD4AB in EL95 at 1852.”
Last week, we mentioned old military surplus Command radios converted to SSB, and John Laney, K4BAI, of Columbus, Georgia wrote: “The conversion of a Command Set to SSB was called the W2EWL conversion. I think a ham with that call wrote an article for QST about it. I bought one in the late 1950s or early 1960s that someone else had converted. It would work 75 meters well and worked a bit on 20 meters. I think I had figured out a way to use it on CW also.”
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.