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 Previous: Greg Widin, K0GW, Appointed ARRL Dakota Division Vice Director |  Next: It Seems to Us: Interoperability |
Last week's report stated the possibility that zero-sunspot days were about to end, but no such luck. Instead we've seen no sunspots for three weeks straight, since September 7. Geophysical Institute Prague predicts unsettled conditions for September 28, unsettled to active September 29, unsettled September 30, quiet October 1, unsettled October 2-3 and quiet to unsettled October 4.
Sunspot numbers for September 20 through 26 were 0, 0, 0, 0, 0, 0 and 0 with a mean of 0. The 10.7 cm flux was 66.8, 66.9, 66.7, 66.3, 66.1, 66.2 and 66.5 with a mean of 66.5. Estimated planetary A indices were 10, 9, 11, 15, 10, 6 and 3 with a mean of 9.1. Estimated mid-latitude A indices were 6, 7, 10, 11, 7, 5 and 2 with a mean of 6.9.
The September 20 forecast from NOAA and the US Air Force showed solar flux (the amount of energy we receive from the Sun at a wavelength of 10.7 cm or 2800 MHz) values rising to 70 on September 21. The next day's prediction reverted to 67. The September 21 prediction had solar flux rising to 70 again, but not until September 29-October 1, then falling back below 70, then back to 70 again for October 18-28.
The September 27 forecast has solar flux staying around 67-68, all the way through November 11. You can see all the latest daily forecasts for solar flux and planetary A index here. The possible end to the stretch of zero-sunspot days was based on the observation that when the solar flux is 70 or higher, there is at least one visible sunspot. This makes it seem that we are still at the bottom of the cycle, or haven't quite reached it.
Those daily forecasts are posted after 2100 UTC. There is a new sunspot, number 970, emerging, so perhaps the September 28 forecast will show solar flux back to 70 or higher. There is currently a solar wind hitting the Earth, and with the interplanetary magnetic field pointing south, this leaves the Earth vulnerable. That same forecast on September 27 predicts a planetary A index for September 28-October 3 at 15, 25, 12, 8, 8 and 15, so we may see unsettled to active geomagnetic conditions on Saturday, September 29 and again Wednesday, October 3.
Already, early Friday morning UTC (which is late Thursday on the West
Coast), we've seen the planetary K index as high as 6. Lately, with quiet conditions, the K index has been 1 or 2. Higher than 3 is considered unsettled or active geomagnetic conditions.
Jeff Lackey, K8CQ, of St Simons Island, Georgia, wrote in with an interesting observation. He created a graph (which unfortunately is not on the Web for viewing) that plots periods where the solar flux drops below 80 for extended periods. It shows the longest run at the end of cycle 22 was from January 8-July 7, 1996, a total of 182 days. The second longest run from 11 years ago was 112 days from August 2-November 21, 1996. The latest, and also the longest run at the end of the current cycle 23, began on June 9, 2007, and so far runs 112 days through September 28. The September 28 morning reading at Penticton (the noon reading is the official value) has a very low solar flux value of 64.4.
The latest forecast from the Air Force shows solar flux below 80 for the next 45 days, so if this turns out to be true, that would put this run up toward the longest one from 11 years ago. We are today already equal to the second longest run of cycle 22, and are in the longest run of the current cycle. The second longest run for the current cycle is 77 days, ending after April 25, 2007.
Note there is nothing magic about a solar flux value of 80, but Jeff is a numbers guy and found this to be an interesting threshold for his analysis of solar minima.
Despite the lack of sunspots, hams are still communicating around the world, and reports of working 3B7C with modest stations are still coming in. Mike Mardit, WA2VQW, of Yorktown Heights, New York, worked them on 30 meters from his car at 2115 UTC on September 18 while sitting at a traffic light. He was on his way to higher ground, but never made it, instead working the DXpedition while stuck in traffic. William Turner, W4WNT, of Oak Island, North Carolina, reports a 30 meter 3B7C contact at 0212 UTC on September 22 using an 80-20 meter fan dipole bent around his deck at 30 feet.
On September 18, Ken Tata, K1KT, of Warwick, Rhode Island, noticed an online propagation map tracking 2 meter APRS stations showed a path from Rhode Island to Newfoundland's Avalon Peninsula. Ken was running 50 W into a dipole, a driven element removed from an 11 element Yagi and mounted on a pole. He reports, "I worked VE1PZ, in FN85, 100 miles north of Halifax; VE1HD, FN95, 100 miles east of Halifax, and VE1AHM, FN76, near Moncton, New Brunswick." He reported that many of the better equipped stations in southern New England were working into the Maritime Provinces on 432 and 1296 MHz. Ken didn't say what mode he used, but he sent along some Web-based VHF propagation sites he likes for checking real-time conditions:
http://www.mountainlake.k12.mn.us/ham/aprs/, http://www.dxinfocentre.com/tropo.html, http://www.vhfdx.net/spots/map.php and http://dxworld.com/144prop.html.
Texas QSO Party
This weekend is the Texas QSO Party, and if I were in California, to work Texas I would try 15 meters 1900-2230 UTC, 20 meters 1500-0230 UTC, 40 meters any time, but the best bet is probably 0200-1200 UTC and 80 meters 0230-1230 UTC.
From Atlanta to Texas: 20 meters 1830-2030 UTC, 40 meters best 2230-0230 UTC, 80 meters 2200-1330 UTC.
From Seattle: 15 meters 1930-2230 UTC, 20 meters 2100-0300 UTC, 40 meters best 0130-1230 UTC and weakest 1630-2100 UTC, 80 meters 0300-1300 UTC.
From New York: 20 meters 1500-0030 UTC, 40 meters best 2330-1130 UTC and weakest 1530-2000 UTC, 80 meters 0130-1030 UTC.
From Ohio: 20 meters 1500-2300 UTC, 40 meters almost around the clock, but 0630-1030 UTC may be questionable, and best signals 2200-0400 UTC and 1130-1400 UTC. 80 meters 2230-1300 UTC, with strongest signals 0030-0200 UTC and around 1130 UTC, weakest signals 1600-1930 UTC.
All of these are best guesses worked out with W6ELprop. Look for details on using this tool in back issues of this bulletin.
For more information concerning radio propagation, see the ARRL Technical Information Service. A detailed explanation of the numbers used in this bulletin can be found here. An archive of past propagation bulletins can be found here. Monthly propagation charts between four USA regions and 12 overseas locations are available at here.
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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