The K7RA Solar Update


Solar activity pulled back over the past week, following a stellar performance in the week prior. The average daily sunspot numbers were down 34.3 points to 129, but the average daily solar flux actually rose 9.7 points to 157.4. Sunspot numbers for January 10-16 were 145, 166, 156, 126, 128, 120 and 62, with a mean of 129. The 10.7 centimeter flux was 173.9, 172.3, 168.5, 156.4, 154.1, 139.7 and 137.1, with a mean of 157.4. The estimated planetary A indices were 3, 2, 3, 9, 8, 4 and 5, with a mean of 4.9. The estimated mid-latitude A indices were 2, 3, 2, 10, 6, 4 and 3, with a mean of 4.3.

The current prediction is for solar flux at 125 on January 18-20, 120 on January 21-22, 115 on January 23-24, 130 on January 25, 135 on January 26-28, 130 and 135 on January 29-30, 140 on January 31-February 1, 150 on February 2, 155 on February 3-4, 150 on February 5-11, then down to 145, 140, 135, 140 and 145 on February 12-16. The predicted planetary A index is 10, 15 and 18 on January 18-20, 8 on January 21-22, 5 on January 23-February 4, 8 on February 5, 5 on February 6-8, 8 on February 9-10, and back down to 5 on February 11 through the beginning of March.

The most active geomagnetic day was January 13, but only in relation to very, very quiet recent conditions. The mid-latitude A index was 10, while the K index only reached 4 in one 3-hour period. The college A index (from Fairbanks, Alaska) was 11 and 12 on January 13-14, with the K index reaching 4 in two 3-hour periods on February 13, and 5 in one 3-hour period on February 14. The reading before that K index of 5 was 0.

There is a possibility of aurora on Sunday, January 20. NOAA reports the geomagnetic field is expected to be at minor storm levels today (January 18), active levels on January 19 and minor storm levels again on January 20. A strong solar wind on January 17 was due to the waning effects of a CME (coronal mass ejection) on January 13. Solar wind may rise again on January 19 as the result of a coronal hole rotating into geo-effective position. A CME on January 16 could cause a rise in geomagnetic activity on January 20. Effects should decrease to background levels by mid-day (UTC) on January 20.

The Australian Space Forecast Centre issued a warning at 2335 on January 17 about increased geomagnetic activity for January 19-20 due to a CME. For January 19, they predict quiet-to-unsettled conditions, but with active to minor storm periods after 1200. For January 20, they predict unsettled-to-active conditions, with minor storm levels possible.

Jon Utley, K7CO, reports that on January 11, he was in New York using a 5 element monoband Yagi at 100 feet. He worked XV1X at 1334 (Vietnam) and XW4XR at 1600Z (Laos) on 10 meter CW long path.

Also on January 11, Jeff Hartley, N8II, in West Virginia reported the following: “I have operated every evening this week with poorer than expected results. Before Thursday, January 10, 12 and 10 meters were closed here very shortly after sunset to all areas. On the morning of Sunday, January 6, A45XR in Oman was S9 on 10 meter long path, but the band was never really open to Europe unless I rechecked it a bit late. VR2XMT in Hong Kong was about S5-7 on 12 meter SSB long path on Sunday. All of the higher bands still seem to close pretty early -- including 20 meters both west and north -- by 0200, but I expect by today things are better. On Thursday, I heard Hawaii on 10 meters until past 2250, and there were also West Coast and South American stations on 10 until around 2230. I have been looking for Asia long path QSOs on 20 and 30 meters without much luck, but I did manage to catch UK8OM in Uzbekistan on 30 meters short path around 0100.”

Rick Radke, W9WS, of Balsam Lake, Wisconsin wrote: “I just wanted to share an experience I had on Wednesday, January 9. I was checking the bands for DX. As usual, I start on 10 and work on down to 20 to see what’s open. Nothing was happening; in fact, there were very few signals at all. So I went to 40 just looking for a ragchew and out of nowhere, there was ER4DX in Moldova calling CQ with a big signal. We exchanged 59 reports and went our ways. This was 1400 local (2000 UTC) on a sunny afternoon in Northern Wisconsin, a good three hours before grayline on this end. In almost 50 years of hamming, I’ve never seen 5000 miles of 40 meter propagation mid-day. I’m running nothing special here, just 1 kW to a vertical with a bunch of radials.”

W6ELprop indicates that between ER4DX and W9WS on 40 meters on that date, signals may have taken a 10 dB jump from 2000-2030, and another 10 dB by 2230. I used 45.456° N, 92.42° W for Rick’s location, and using the grid locator from an image of an ER4DX QSL card (KN38vk), this AMSAT tool shows 48.438° N, 27.792° E at the other end. W6ELprop shows this is a 5016 mile (or an 8073 kilometer path), and about six hours after sunset at 2030 in Moldova. So conditions were probably favorable, and ER4DX was probably putting out a big signal, perhaps with a large 40 meter Yagi. Using today’s date (January 18) shows that first 10 dB bump moving out by 30 minutes, to happen around 2030-2100 instead of 2000-2030.

Reg Beck, VE7IG, of Williams Lake, British Columbia, wrote on January 12: “I had the long path openings on 10 and 12 meters for three days here before they petered out. I still saw W6 stations working long path after it closed after the three days. I worked Oman, the United Arab Emirates, Bahrain and Saudi Arabia on 10 meters; I also worked Oman, the United Arab Emities and Qatar on 12 meters. What was very surprising to me was the immediate resurgence of 160 meter propagation right after the 10 meter long path propagation stopped! There were Europeans all over the band that I easily worked -- it was just like during the sunspot minimum with relatively low noise levels. It was pretty amazing propagation up here in the northern end of the Pacific Northwest.”

Reg is way up north in British Columbia, not down near the border. Seattle is 47.7° N latitude, Vancouver BC is 49.2°, and VE7IG is just north of 52° in Williams Lake.

Oleh Kernytskyy, KD7WPJ, in Salt Lake City, Utah wrote: “Solar flux was 170 on January 12. I called CQ with 5 W and an indoor dipole on 28.060 MHz and immediately received a response from Frank, N3FLL, in West Chester, Pennsylvania. He also operated QRP with 5 W and used a dipole. I was impressed with this contact, because my eastern direction is blocked by the Wasatch Mountains.” In another e-mail, Oleh wrote: “We had solar flux 158 and a K index of 2 on January 13, producing a short opening on 28 MHz. I had a QSO with CE2AWW in Chile, using 5 W and indoor dipole. The distance between our stations is 5707 miles.”

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.