QST de W1AW
> Propagation Forecast Bulletin 38 ARLP038
> From Tad Cook, K7VVV
> Seattle, WA September 13, 2002
> To all radio amateurs
> SB PROP ARL ARLP038
> ARLP038 Propagation de K7VVV
> The sunspot count remained fairly high this week, with the numbers
> still bouncing around over 200. Average daily sunspot numbers rose
> nearly 15 points this week and solar flux was up by 22. This has
> been quite an active week geomagnetically. Sunday, Tuesday and
> Wednesday were quite active, producing impressive aurora displays in
> northern latitudes. When this happens, polar HF propagation goes
> away or gets very weak. A year ago at this time the average sunspot
> numbers were 34 points higher and solar flux was higher by near 42
> OK1HH sent an email about the Geophysical Institute Prague showing
> predicted geomagnetic activity for the upcoming week, and it shows
> quiet conditions on September 18-19, quiet to unsettled on September
> 15 and 17, and unsettled on September 13, 14 and 16. Solar flux
> ranging from 170 to 220 is predicted.
> For the next few days NOAA's forecast from the US Air Force shows a
> planetary A index of 12, 12, 8 and 8 for Friday through Monday, and
> solar flux at 215, 220, 225 and 220. This forecast shows flux values
> dipping below 200 by September 22.
> WB9SAT writes from Eagar, Arizona about his solar observations. He
> uses an 8-inch Schmidt-Cassegrain telescope, and says recent
> sunspots were spectacular. He asked about calculating sunspot
> numbers at home, and after investigation wrote, 'The formula,
> R=k(10g+f) allows me to accurately estimate the sunspot activity
> using the point system when viewing the sun.'
> He goes on to say, 'According to NASA, the best way to count the
> sunspots is to project the sun's image the size of 25 cm (9.84') on
> a piece of white paper.'
> He also looked at a number of sites, including
> nssdc.gsfc.nasa.gov/space/model/solar/sunspot.html and
> Don't forget the autumnal equinox, which this year is at 0448z on
> September 23. This is a great time for DX, especially when the
> geomagnetic field is quiet.
> Sunspot numbers for September 5 through 11 were 225, 189, 180, 221,
> 194, 226 and 213, with a mean of 206.9. 10.7 cm flux was 175.2,
> 178.1, 182.8, 191.6, 206, 220.5, and 216.1, with a mean of 195.8.
> Estimated planetary A indices were 10, 10, 45, 26, 10, 24, and 28,
> with a mean of 21.9.
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