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The K7RA Solar Update


We've now observed sunspots continuously for the past 30 days -- certainly a turnaround from the quiet conditions of the past few years. In fact, in 10 weeks, we have seen only three days with no sunspots: December 25, January 6 and January 19. This is a little more than 4 percent no-sunspot days, a nice contrast with all of 2009, with more than 71 percent days with no sunspots. Sunspot numbers for February 11-17 were 64, 38, 37, 28, 27, 28 and 49, with a mean of 38.7. The 10.7 cm flux was 94.2, 95.5, 94.1, 89.4, 87.6, 86.8 and 86.9, with a mean of 90.6. The estimated planetary A indices were 5, 6, 3, 4, 14, 9 and 4, with a mean of 6.4. The estimated mid-latitude A indices were 4, 4, 2, 3, 8, 11 and 2 with a mean of 4.9. Since the first of the year, the average weekly sunspot numbers were 14.6, 26.4, 18.6, 28, 14.6, 43.3 and 38.7.

Sunspot group 1049 emerged on Wednesday -- and it is growing! The minimum non-zero sunspot number is 11. This is because the numbers are derived from the number of sunspot groups, plus areas inside the groups. Each group counts for 10, so the minimum sunspot number is 11 and the minimum sunspot number for at least two sunspot groups is 22. In 2009, only 87 days (23.8 percent) had sunspot numbers greater than 11; 21 of those days were in December. Only 43 days (11.8 percent) had a sunspot number greater than 15 (14 of those in December) and only 26 days in 2009 had a sunspot number of 23 or more (none had 22).

This weekend is the ARRL International CW DX Contest and there is every reason to expect continued good conditions. The predicted planetary A index for today, February 19, is 10, followed by 5 for the next week. The solar flux for February 19-25 is predicted at 85, 85, 84, 84, 82, 80 and 78. Geophysical Institute Prague predicts quiet to unsettled conditions for February 19 and quiet conditions February 20-25.

The wonderful STEREO tool disappeared about a week ago and hasn't been seen since. Server problems, I am told, but the folks at NASA who work on the STEREO project say it is out of their hands. They keep expecting it to return in the next 24-48 hours, but it hasn't yet. If you go here, you can see current images from the program; note that the end of that URL is a date that you can change to see images from different days. We just don't get to see that marvelous and very useful spinning sun animation. This page also has links to data, but I don't pretend to know what much of it means. Next Thursday -- February 25 -- images from the STEREO spacecraft will achieve 88 percent coverage of the Sun.

Many e-mails have been coming in this week about a new application for the iPhone that gives real-time views of the sun from STEREO; it will even alert users if a significant event is taking place. It is called 3D Sun and you can find out more about it here and also in an article here. Another propagation related iPhone app was released last year that you can peruse here.

We have some new links this week for those who like to monitor ionospheric sounders, or ionosondes. For an introduction, go here. Check out this Web site for a geographic view of ionosonde stations and access to their real time data.

Carl Luetzelschwab, K9LA, sent a link to an article from 2007 summarizing what must be all the known predictions for the current Solar Cycle 24. Note the last page has a colorful representation of the range of predictions.

There is a new article on helioseismology this week in Science Daily.

Angel Santana, WP3GW, of Trujillo Alto, Puerto Rico, had fun on PSK31 on February 15. At 1500 UTC, he heard on 2 meters that 12 meters was active. Then he went to 15 meters where he heard Western Europe and the Caribbean. There were many PSK31 signals on 20 meters. Then at 1700 UTC, he worked EI3GBS and 9H4N on 17 meters. Angel wrote, "At 2000 UTC, I went to 10 meters and heard USA, which had been absent for some months. I began to call on 28.465 and K4KV answered at 2012. He told me he was listening via backscatter and I told him my antenna was pointing to Africa/Europe and he was booming in. Then I went to 40 meters at 2245 UTC and worked 9A3AGS from the island of Brak. I heard the band was so crowded, we say here in Spanish, 'esta Esplaya!' coined by Fernando, KP3AH." Check out Angel's personalized page here.

Jim Puryear, N5TSP, at EM00xf in Austin, Texas, wrote "On February 13 at 0300 UTC, I noted E-skip propagation from XE1 on 10 and 6 meters coming into Central Texas. Then I heard VK2APG on 28.485 calling CQ and made a quick QSO with signals about 55 each way. I imagine this may have been an E-skip hop to XE1 followed by F2 to VK -- a pleasant surprise for a late evening on the upper end of HF. Now if we can just get this happening on 6 meters."

Jeff Hartley, N8II, of Shepherdstown, West Virginia, has been excited about increased solar activity and better conditions. He asked for a good site to get solar flux data. The most immediate is straight from the observatory in Penticton, British Columbia. You will note there are three readings per day, and the one at local noon (2000 UTC) becomes the official solar flux number for the day. Later it is rounded off and posted with the sunspot number here.

Jeff sent this report yesterday, February 18: "I feel we have turned the tide on very low solar activity and now can expect low to moderate activity consistently with daily good 17 and 15 meters openings to EU from this area. I took the day off from radio Saturday, and Sunday February 14, it didn't take long to realize something was up; at 1333 UTC I checked 15 meters to find lots of EU signals; I called E73XL and a UA4 running QRP 1 W called me as I was signing. We QSY'd up and UA4HFD went in the log first followed by the 1 W station UA4CDV who was S3. Even during the good conditions on 15 during the CQWW phone last October, there was little or no opening to UA4.

"So, after a breakfast break at 1358 UTC, I check 12 meters to find the band just opening to EU. PY0FF was logged, then I called CQ. The first QSOs were with HA and OK, followed shortly by weak LA5YJ at 1416 UTC. OQ5M was S9+, then at 1435 UTC, 4Z4DX was logged S9 followed by a very loud OZ8ABE; 9X0CW was S7 next. The band was in good shape until after 1535 UTC when I stopped. Monday was a day of strange conditions with obviously some solar flare activity. For example, at 2217 UTC -- well after the normal opening -- I worked OH3SR on 17 meters and he went from S5 to S9, then back again to S5 within about a minute, the QSO was probably via auroral-E. Fifteen meters was open well to EU all morning, but the remarkable QSOs were with UX1UF and ER4DX (S9+) around 1650 UTC about 2 hours after their sunset. Signals from western EU were booming in then. Twelve meters was open well to the Caribbean/SA most all of the day and was marginal to EU, with only a few Is and EAs answering my CQs. 3B8DB was S5 at 1543 UTC. TX4T was logged on 17 meters CW very early at 1612 UTC. But 12 meters blew wide open to EU from 1730-1800 UTC with some incredibly loud signals from western EU; the Belgians seemed to have the sweet spot on the other end with a couple of them well over S9, including ON7TZ and a couple of QRP stations, ON3VR and ON6AB S5-S7. Ten meters opened for about 45 minutes to the West Coast around 1900 UTC, then around 1945Z TX4T was worked on 10 meter SSB and FO/N6JA was logged at 2122 on 10 meter CW (both French Polynesia) followed by very loud signals from LU and PY. PU2KLM was over S9 with just a vertical and 100 W on his end.

"Also of note was stateside propagation. I chase counties. Toward sunset, N4JT/M in Louisiana was S9 or better on 20, 30 and 40 meters near the same time. Also around 2300 UTC on 40 meters, everyone calling him on the net from New York, Pennsylvania and Virginia to Missouri and Minnesota and farther was S9 or better, and N4JT was about 15 dB over S9. I've never heard 40 meters that good for several years, going back to near the peak of the last cycle. Fifteen meters has been open to JA between 2230-2315 UTC quite a few days and 17 meters open daily and longer." Thanks Jeff.

Randy Crews, W7TJ, of Spokane, Washington, sent a URL for a site I'd lost track of for some time.

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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