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The K7RA Solar Update


In addition to the sunspot group 1029 that graced us from October 23-30, a new Solar Cycle 24 spot -- 1030 -- just emerged on Thursday. It is currently in a maximally geo-effective position (in other words, in the center longitudinal meridian as viewed from Earth), and may provide some enhancement for the ARRL CW Sweepstakes this weekend. On Thursday, the daily sunspot number was 15. Sunspot numbers for October 29-November 4 were 19, 13, 0, 0, 0, 0 and 0 with a mean of 4.6. The 10.7 cm flux was 76.7, 75.2, 75.1, 72.3, 71.4, 71.5 and 71.4 with a mean of 73.4. The estimated planetary A indices were 7, 11, 1, 2, 2, 0 and 0 with a mean of 3.3. The estimated mid-latitude A indices were 5, 8, 1, 2, 2, 1 and 1 with a mean of 2.9.

Geomagnetic indices continue to stay very quiet. Checking numbers here, you can see that the planetary K index and the college K index were a solid 0 for all of November 3-4 and most of November 5. One strange (at least, to me) set of numbers is on November 5, when the K index in all three zones was exactly the same. It was 0 all day, then for one three hour period it was 1, then back to 0 for all three -- planetary, college and mid-latitude. The A index is calculated using the K index data; the A index for that day was 0 at mid-latitude and high latitude, but was one for planetary numbers. Why was that?

Expect geomagnetic conditions to remain quiet and stable. NOAA and the US Air Force predict planetary A index at 5 for today, November 6, and 7 for November 7, then back to 5 for November 8-19. Geophysical Institute Prague predicts quiet to unsettled conditions November 6-7 and quiet conditions November 8-12.

October had some good numbers, with an average daily sunspot number of 7.0, the highest level since March 2008. Our three-month moving average showed 4.64 for August-October, centered on September. This was up from 4, centered on both July and August. Three month averages centered on January-September 2009 were 2.19, 2.02, 1.49, 2.01, 4.22, 5.2, 4, 4 and 4.64.

Tom Morton, CX7TT, of La Paloma, Rocha, in Uruguay, sent a message on October 30 concerning the CQ World Wide SSB DX Contest and his operation on 10 meters: "Around 1 PM local time on Saturday, 10 meters opened with a bang and propagation was awesome to EU then later the US. I expected 10 to shut down on Sunday, so I spent a lot of time Saturday milking the band. Even though I did foray down to 15 meters on both days, I wound up with 1000 QSOs, 93 countries and 22 zones. What a blast!"

Jim Brown, W5ZIT, of Farmersville, Texas, had a question about propagation that surprised him on 17 meters. Jim wrote, "I thought I would drop you a note concerning an unusual QSO I had on October 30. At 2350 UTC, I worked AE5PW in Newport, Arkansas on 17 meters using the Olivia mode. Signals were 20 over 9 for a few minutes and then faded down to S5 before we signed. I am located about 30 miles Northeast Dallas. This distance was something like 250 miles or less, and I thought this very unusual at the time. I was wondering what type propagation would support this short skip on 17 meters. It would seem to be too short even for Sporadic E. I was using a 550 foot loop up 30 feet at the time."

I took the addresses for W5ZIT and AE5PW from FCC records and calculated the distance at 297 miles. But note that for an antenna, Jim is using a 550 foot wire strung in a loop, 30 feet above the ground. Perhaps there is some high angle radiation going on and the change in signal strength was due to some drifting patch of ionosphere above the two stations. This was on the last day of an eight day run of sunspots. Jim said he is using Olivia, which is a robust digital mode for HF (check here and here for more information on Olivia). I thought perhaps the 550 foot figure was a typo, but I checked out Jim's QTH here (click on "Bird's eye" then zoom in) and see that there is plenty of room to stretch out.

Clay Melrose, WA6LBU, of Wellston, Oklahoma, and Chuck Kershner, W1EMQ, of Clinton, New York, were both pleased by long distance contacts on 40 meters on November 1. W1EMQ worked UU1CC in Crimea on CW at 0050 UTC with good signals using an old 4BTV vertical in wet soil and a Drake TR4. WA6LBU worked ZS3D running 25 W SSB with a MP-25 manpack military radio into a G5RV at 0600 UTC; ZS3D was using a 40 meter hexbeam.

Thanks so much to Steve Nichols, G0KYA, for writing the bulletin last week. See his blog here.

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 in The ARRL Letter. Check 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.




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