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 Previous: Surfin': Finding Friends in the Fed |  Next: Hams a Bright Spot During Power Blackout |
SEATTLE, WA, Aug 15, 2003--The average daily sunspot numbers for the week was about the same this week as last, and daily solar flux was only slightly higher. Solar flux is expected to peak over the next few days--such as it is in this declining phase of the solar cycle. Expect solar flux values around 135 for Saturday, August 16. Solar flux is expected to gradually decline to below 100 around August 24. Geomagnetic indicators should be unsettled to active Friday, August 15, but should quiet down over the next week. Predicted planetary A index for August 15-18 is 20, 15, 10 and 10.
Currently there is just one sunspot group facing Earth, and it seems to be growing fast as it moves into optimum position for Earth-directed radiation. This presents a wild card for conditions over the next couple of days, since it could be the source of increasing solar wind.
Some editions of last week's bulletin contained a claim that in 57,617 BC Mars was only 34.62 miles from Earth, which of course was not the case. This calls for a visit to a news item on the Bad Astronomy Web site. Phil Plait of Sonoma State University in California runs the Bad Astronomy site to help dissuade and debunk some misconceptions that creep into films, television, popular culture and even science textbooks.
In an August 13 item he talks about the excitement over Mars being close to earth, and points out that it will be only about 1 percent closer than it was in 1971.
Bruce Irving of Eagle, Idaho, was K7ISM many years ago, and he wrote this week asking about some ghosting he saw on his television set after 0200 UTC on Sunday, August 10. He wasn't able to ID the station, but noted that the image of a musical group performing wasn't on any of his other local channels in the Boise area. He asked if this could be skip from a channel 2 station outside his area. I believe his hunch is correct. He noted that channel 2 is just about the same frequency as the 6-meter ham band, and--being the lowest-frequency TV channel--it is the one most likely to experience long distance propagation. In this case, it was probably some summertime E-layer propagation.
For more information on propagation and an explanation of the numbers used in this bulletin see the Propagation page on the ARRL Web site.
Sunspot numbers for August 7 through 13 were 121, 111, 107, 112, 118, 114 and 112, with a mean of 113.6. The 10.7-cm flux was 137, 132.9, 130, 131.1, 129.2, 123.3 and 130.8, with a mean of 130.6. Estimated planetary A indices were 15, 32, 15, 12, 11, 25 and 17, with a mean of 18.1.
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 also appears in The ARRL Letter. Readers may contact the author via k7ra@arrl.net.
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