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 Previous: ARRL In Action: What Have We Been Up To Lately? |  Next: ARDF Update: Champions Among Us? |
SEATTLE, WA, Dec 2, 2005--Daily sunspot and solar flux averages over the past week were down, and the geomagnetic indices were up. Average daily sunspot numbers were down nearly 15 points to 33.7, and average daily solar flux declined nearly 13 points to 84.2.
Currently sunspot and solar flux numbers are rising due to Sunspot 826, which is growing rapidly and moving toward the center of the solar disk, giving it maximum influence here on Earth. It also could be a source of flares, which would not be good for the ARRL 160 Meter CW Contest this weekend. Predicted solar flux for Friday through Monday, December 2-5, is 100, 105, 105 and 105. Predicted planetary A index for the same days is 15, 12, 8 and 5, although those numbers will be higher if Sunspot 826 becomes especially active.
The November 18 edition of the "Solar Update" included a report describing how WB5AGZ in Stillwater, Oklahoma, heard a 10-meter repeater from New York (KQ2H) during the middle of the night and into early morning. We now have another similar report, also from Oklahoma. Stan Stephens, WA6SKD, of Midwest City, wrote in with this narrative:
"Now for the good part. These late night signals are not limited to KQ2H. I have also noted signals from the southern US and Midwest with an occasional California 10 meter FM repeater. Also, like Martin, I notice no other signals on 10, 12, 15 and 18 meters. Trying to raise these repeaters can be difficult on my Azden PCS 2800 (10 W and Ringo), but when I do get a response from the machine, no one is home!
"In general I find the 10 meter FM band is open a lot more than it is given credit for. I am not sure what conditions allow this, but no complaints on this end. It is cool making a 10 meter FM contact with a distant station at 0300. I have been on 10 FM with my Azden for 23 years; my log books really show varied conditions on 10 meter FM. Although some years have been better than others, this includes sunspot cycle minimums.
This is very interesting, and shows us that 10 meters may be open more often than we think, even in the middle of the night when there shouldn't be any conventional propagation. Remember that the ARRL 10 Meter Contest is coming up December 9-11.
Now that November is behind us, let's look at the monthly averages for solar flux and sunspot numbers.
The average daily sunspot numbers for the months September 2004 through November 2005 were 50, 77.9, 70.5, 34.7, 52, 45.4, 41, 41.5, 65.4, 59.8, 68.7, 65.6, 39.2, 13 and 32.2. Average daily solar flux for the same months was 103, 106, 113.7, 95, 102.3, 97.2, 89.9, 85.9, 99.5, 93.7, 96.5, 92.4, 91.9, 76.6 and 86.3.
It looks like activity bounced back a bit in November, but look for the general trend to be down until the sunspot minimum, which should be about a year from now--possibly a bit later.
For more information concerning propagation and an explanation of the numbers used in this bulletin see the ARRL Technical Information Service Propagation page. An archive of past bulletins is on the ARRL Web site.
Sunspot numbers for November 24 through 30 were 30, 39, 30, 26, 27, 27 and 57, with a mean of 33.7. The 10.7 cm flux was 86.6, 79.9, 80.8, 80.7, 81.9, 84.7, and 94.7, with a mean of 84.2. Estimated planetary A indices were 9, 10, 5, 2, 9, 5 and 10 with a mean of 7.1. Estimated mid-latitude A indices were 6, 8, 3, 2, 6, 6 and 9, with a mean of 5.7.
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.
| Previous: ARRL In Action: What Have We Been Up To Lately? | Next: ARDF Update: Champions Among Us? |
