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SEATTLE, WA, Jan 19, 2007 -- Average daily sunspot numbers for the week were down 16 points from the previous week to 27.4. Geomagnetic conditions were unsettled on Monday through Wednesday, January 15-17. Don't look for any radical changes in activity over the near term, with the next period of moderate geomagnetic activity set for January 30. Expect geomagnetic conditions to become progressively quieter over the next few days. Geophysical Institute Prague predicts unsettled conditions for today, January 19, quiet to unsettled January 20 and 21, and quiet on January 22-25.
Bill Van Alstyne, W5WVO, of Rio Rancho, New Mexico, wrote to remark that this winter's 6 meter E-layer propagation season has been poor. East Coast operators have had one or two more openings than western states. Bill has counted three openings in New Mexico -- on December 8-9, December 12-13, and January 8-9. He reports his 6 meter QSOs have been running close to 70 percent behind last year's, with only 50 so far as compared to 160 at this time in 2006. Bill notes that 6 meter operators he's talked to in the northwestern, north-central, midwestern and south-central states are reporting the same conditions.
Nearly 550 miles east-northeast of Bill in Wichita, Kansas, Jon Jones, N0JK is quite excited about the 6 meter opening January 8-9. He says it sounded like a summer opening at times, and at one point he had stations from districts 2, 3, 4, 5, 7 and 8 coming through at the same time. On January 9 on 2 meters, Kansas and Oklahoma stations worked North Carolina and Florida. Jon worked XE1MM and XE3ARV on 6 meter CW on January 9, and he noted that XE3ARV is about 2300 km (a little more than 1400 miles) from him.
Ray Parker, ND6S, of Sutter Creek, California, wrote to report the fun he's had at the bottom of the solar cycle working Africa on 15 and 20 meters this month. Running 100 W he worked 3DA0TM in Swaziland on January 4 at 2109 UTC on 20 meters and XT2C in Burkina Faso on January 11 at 1824 UTC on 15 meters with great signals. Running the average sunspot numbers during those times through propagation prediction software for the paths to Burkina Faso and Swaziland from California showed those were good times of the day for that propagation.
Dave Mays, W8UI, of St Marys, West Virginia, mentioned a Handiman's Guide to Solar Activity and HF Propagation for the QRPer by Paul Harden, NA5N, that Dave read about in the ARRL Contest Rate Sheet. The GQRP Club offers the guide on its Web site. This single-sheet resource illustrates sunspot groups and has a guide to geomagnetic indices and storms.
For More Information
For more information concerning propagation and an explanation of the numbers used in this bulletin see the ARRL Technical Information Service Propagation page and the article "The Sun, the Earth, the Ionosphere: What the Numbers Mean, and Propagation Predictions," by Carl Luetzelschwab, K9LA. An archive of past bulletins is on the ARRL Web site. The propagation charts that formerly appeared in QST now are available on the QST Propagation Charts page on the ARRL Web site.
Weekly Sunspot Numbers
Sunspot numbers for January 11 through 17 were 45, 33, 36, 27, 16, 18 and 17, with a mean of 27.4. The 10.7 cm flux was 83.9, 83.8, 81.4, 82.1, 82, 78.7, and 78.1, with a mean of 81.4. Estimated planetary A indices were 6, 3, 1, 2, 22, 13 and 26, with a mean of 10.4. Estimated mid-latitude A indices were 4, 2, 0, 2, 14, 9 and 15, with a mean of 6.6.
Amateur solar observer Tad Cook, K7RA, 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. Readers may contact the author via e-mail.
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