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The K7RA Solar Update


This was another week where average daily sunspot numbers declined, while average daily solar flux increased. Sunspot numbers for January 19-25 were 117, 88, 102, 103, 108, 105 and 68, with a mean of 98.7. The 10.7 cm flux was 157, 141.2, 141.6, 141, 144.3, 135.7 and 126.4, with a mean of 141. The estimated planetary A indices were 3, 4, 6, 21, 9, 17 and 14, with a mean of 10.6. The estimated mid-latitude A indices were 1, 3, 6, 22, 7, 13 and 17, with a mean of 9.9.

The predicted solar flux is 120 on January 27-30, 125 on January 31-February 2, 120 on February 3, 140 on February 4-8, 145 and 150 on February 9-10, 155 on February 11-13, 150 on February 14-19, and then 145 on February 20-23. That’s right -- the long-anticipated short-term solar flux peak of 165 from February 17-21 is gone. The last forecast which still held this number was on January 23, and on January 24 it changed. The predicted planetary A index is 5 on January 26, 8 on January 27-28 and 5 on January 29 to February 7, 8 on February 8-9, and then 5 again on February 10-23

At 0617 UTC on January 22, an impact from a coronal mass ejection caused the high-latitude college A index to reach 38, sparking aurora; the index hit 38 again on January 25. On January 23 around 0400 UTC, a powerful M9 solar flare erupted, and this was right on the threshold of becoming an X-class flare. The CME hit Earth around 1500 UTC on January 24, causing bright aurora. Watch a lovely video of the event. Also check out this British report and this one from Montreal.

As this bulletin is being written early Friday morning, sunspot group 1408 is facing Earth directly, but it is weak. Group 1402 is passing below the western horizon, and 1410 is coming around from the east. It looks like a very active region is all the way on the other side of the Sun at the 180 degree meridian.

Fritz Huttelmayer, WB2QWH, of Cheektowaga (Buffalo), New York, wrote: “I just wanted to give you my observations of 6 meters during the contest this past weekend. I have been on 6 a couple of times over the past two years. I am not a serious VHF operator, as I operate mostly HF QRP CW. I listened in on some of the activity during the January VHF contest. I heard a W4 in Florida exchange grid squares with a W7 in the State of Washington. I also heard stations from Indiana, Nevada and Texas. The band sounded more like 20 meters on a good day. No wonder they call it the ‘Magic Band.’”

Mike Schaffer, KA3JAW, of Tampa, Florida, sent an article about solar flares. Mike also commented about a recent television signal he received from XHTV (running 64 kW) in Mexico City: “On Tuesday, January 24, a Mexican broadcaster on television channel 4 suddenly flashed upon the screen for about five minutes (0002-0007 UTC) due to a sporadic-E flash event that produced a moderately strong signal coming in with a color carrier and audio. The event occurred nine hours after the coronal mass ejection had hit the Earth’s magnetic field at approximately 1500 UTC. Mexico City is 1205 air mile distance at 245 degrees from my location. The best part of an E-skip storm is that you do not have to park your antenna at the precise azimuth toward the transmitter tower site. In my case, the antenna was aimed due south at 180 degrees, which would be 65 degrees off the main beam.”

Thanks, Mike!

Ron McCollum, W7GTF of Winthrop, Washington wrote to ask if I ever heard any theories about the stock market correlating with the sunspot cycle. I have heard of the stock market theory, and various other correlations with solar activity. Every time I hear of it, I think back to my eighth grade math class, when the text had a chapter on correlation, causation and post hoc fallacies. To illustrate, the book displayed a graph comparing smoothed sunspot numbers with cardboard box production in the United States. They seemed to track quite closely.

I get a lot of mail asking about this sort of thing. I like to recall a presentation by Dr James Alcock --a Professor of psychology at York University in Canada -- at Skeptic’s Toolbox in Eugene Oregon about the mind as a belief engine. One of the concepts presented was that the human brain is hard wired for correlation and belief, and how this figures into the evolution of the brain.

This weekend is the CW portion of the CQ World Wide 160 Meter Contest. Expect good conditions, with quiet stable geomagnetic indicators and a temporarily declining sunspot number.

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.



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