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The K7RA Solar Update


After last week’s somewhat downbeat look at sunspot cycles -- current, past and future -- we sure have some great activity to report this week: The average daily sunspot number more than doubled in the past week, rising nearly 93 points to 163.3, while the average daily solar flux was up more than 37 points to 147.7. On top of that, the geomagnetic conditions were very quiet, which is a wonderful combination not often seen in more active solar cycles.

Sunspot numbers for January 3-9 were 116, 167, 181, 186, 196, 144 and 153, with a mean of 163.3. The 10.7 centimeter flux was 128.8, 143.1, 145.1, 142.2, 149.7, 155.6 and 169.3, with a mean of 147.7. The estimated planetary A indices were 2, 2, 3, 3, 3, 3 and 3, with a mean of 2.7. The estimated mid-latitude A indices were 2, 2, 1, 6, 3, 3 and 3, with a mean of 2.9.

There is a bit of uncertainty regarding the mid-latitude A-index for January 5-6. A 24 hour outage somehow blocked the data (from Fredericksburg, Virginia) on eight consecutive 3 hour readings from late January 5 (UTC) through early January 6. The mid-latitude K index tracked closely with the planetary K index from January 3-9, so if the data were not missing, the January 5 mid-latitude A index would probably have been a little higher, while the January 6 mid-latitude A index would be a little lower than reported. The daily A index is based solely upon the eight K index readings throughout the day.

Currently, NOAA and USAF predict solar flux values of 175 on January 11-12, 170 on January 13-14, 165, 150 and 125 on January 15-17, 105 on January 18-19, 110 and 120 on January 20-21, 125 on January 22-24, 130 on January 25-28, 135 on January 29, 140 on January 30-February 1, then 135, 140, 135 and 130 on February 2-5, and back down to 125 on February 6-7. The predicted planetary A index is 5 on January 11, 8 on January 12-13, 5 on January 14-19, 8 on January 20-21, 5 in January 22-25, 10 on January 26, 5 on January 27-February 2, 8 on February 3-5, 5 on February 6-8, and rising to 10 on February 9.

Howard Lester, N7SO, of Schuylerville, New York, recently saw his wire antennas go down in a big wind. The former inverted V is now suspended two feet above ground at the feed point, and 12 feet above ground at each end. So it is now an actual upright V instead of an inverted V. Howard was excited to see what he could work this week, with the fast rising solar flux and sunspot numbers:  “Mysteriously, the antenna system still loads with identical settings on my transmatch. So I decided to try transmitting and called a guy on SSB in Germany. He came back to me with a nice signal report, followed by a guy in Greece. And on 17 meters CW, I broke through a little pileup to Iceland.”

This was from January 9-10. On January 10, Howard wrote that he “made a couple of contacts on 15 SSB to Poland and to Eastern Ukraine, both less than one hour after sunrise. They’re all using giant antennas, so no wonder they hear me. It seems awful early in the morning this time of year for 15 meters, let alone 12 to be open, except that the flux is so high right now.”

With the fast rising solar flux this week, it has been fun to examine the thrice daily readings from the observatory at Penticton, British Columbia. Check the first column on the left for date, the second column for time and the fifth column for the observed solar flux. Daily readings are at 1800, 2000 and 2200 UTC, but the 2000 UTC reading (local noon) is the official solar flux number for the day.

Carl Luetzelschwab, K9LA, of Indianapolis, Indiana, has some observations on recent solar activity: “The new year welcomed us with a nice increase in solar activity. In the past several days I, along with many others, worked A45XR and A65BP (and others) in the late morning hours on 12 and 10 meters via long path to the southwest from here in the Midwest. I even worked VU2XO on 10 meters SSB via long path (to the south) at 1638 on Friday, January 4 -- he was extremely weak but workable. These QSOs are good examples of low probability openings, and they were aided by the increased aforementioned solar activity. The Voice of America Coverage Analysis Program (VOACAP) predicts these openings (even at low solar activity), along with many other low probability paths. You just have to be there when they happen. Both ends of the path are looking toward the equatorial ionosphere, with the highest MUFs in the world (even at low solar activity). Our end of the path is in daylight, which of course is good for these higher band QSOs. The other end is past sunset, but not far enough past sunset to have the MUF decrease significantly -- thank goodness the ionosphere recombines much slower after sunset than it ionizes at sunrise. And more than likely this wasn’t conventional multi-hop -- I suspect chordal hops that kept the losses down.”

Thank you, Carl.

Several readers had comments about past solar cycles, including Lou De Chiaro, WB2IJT, of Lindenwold, New Jersey: “I was fairly active on HF during the late 1960s during the peak of Solar Cycle 20. The best propagation results happened on 10 meters during 1969 and 1970, and I both observed 20 dB/S9 signals and received equally glowing reports from several Australian and New Zealand stations on both CW and SSB. Since then, unfortunately I have not seen signals of comparable strength from ‘down under,’ though one always wants to remain hopeful.”

Ken Bourke, N6UN of San Diego, California, also chimed in: “I was born in 1940 and fit the age group that you talk about and the expectations we had. I enjoyed the current article about this age group as it moved through the 11 year sunspot cycles and it is very accurate and true. No cycle compares to the 1958 one. We old QCWA hams always hope -- and think -- that we will have another cycle like that 1958 one, but it never has happened. In 1958, I was 18 years old, in Illinois (I was W9ZVG back then), with 1 kW and a quad at 60 feet. But I got bored working so many DX countries. I did not know I was experiencing a once-in-a-lifetime event. But I always thought the band would come back like that 1958 event every 11 years, but it never has come back like 1958. I still keep hoping, and I do think that some cycle in the future will be even stronger, with a higher daily 23 centimeter solar flux than the 110 or 120 that we see today. I keep waiting for a lot of long term continuous solar activity.”

Fortunately, solar flux this week is actually peaked higher than 150, rising to 174 on January 10 and predicted to be at 175 on January 11-12.

Tom Gallagher, N6RA, of San Francisco, California, wrote: “I was one of the lucky ones to be on the air and hunting DX in the ’50s. I’m now 70. I was licensed in 1955 as KN4DRO in Miami at the age of 12. I quickly got into DXing (having been an SWL DXer at the age of 10 and a BC band DXer at the age of 6 when my parents gave me my own little BC band radio). In 1958, I received DXCC #3698. I had about 210 countries when I went off to college in 1960 (I was actually the #9 DXer in the state of Florida with my puny station when I went off to college). I had a very modest station -- 50 W on CW and AM (I had 140 countries on AM phone) with a 2 element quad at 30 feet. My experience during the various sunspot cycles was very much like you outlined. I had them all for a while, but missed South Sudan (I haven’t sent in the new PJ cards yet). Six meters has taken my interest in the last 13 years or so. There seem to be a lot of geezer HF DXers on 6! I had hopes of making DXCC on 6 meters, but it’s harder than I ever envisioned from the West Coast, and the sunspots don’t seem to be cooperating. I do have some juicy DX on 6 from 2001, such as Zimbabwe, St Helena, Vietnam, the Philippines, Hong Kong and more.”

See you next week. In the meantime, check out a couple of interesting articles about solar activity here and here.

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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