[South Florida DX Association] ARLP042 Propagation de K7RA

[Bill Marx]

 SB PROP ARL ARLP042
> ARLP042 Propagation de K7RA
> 
> Solar activity was down for the week, in fact we saw several days of
> no sunspots at all. October 1, 2 and 3 each had a daily sunspot
> number of 0. Sunspot numbers are slowly rising as sunspot 813
> rotates to face Earth, but the average for the week dropped over 18
> points to 11.6. Sunspot numbers and solar flux may rise, but
> probably not by much.
> 
> As last week's bulletin mentioned, were waiting to see what the
> return of giant sunspot 798 would bring. But as that area shifts
> into view, only a few wisps are visible, indicating the area is
> magnetically much less complex than what came around the past two
> rotations. Over the next year as this cycle 23 bottoms out, we will
> see long stretches of days with no spots, maybe even weeks, judging
> by the behavior of past solar cycles.
> 
> But with the lower solar activity came very little geomagnetic
> activity. The numbers reported in last week's bulletin were low, but
> the weekly average for planetary and mid-latitude A index dropped
> even lower, by about one point each. If you can check
> http://www.sec.noaa.gov/ftpdir/indices/DGD.txt within the next few
> weeks, before the data disappears, you can see the days with reading
> after reading of K index equal to 0.
> 
> With the K index moving between 0 and 1 and back, this results in a
> daily A index of 2 or 4. If you view the nomograph at
> http://www.sec.noaa.gov/ftpdir/indices/DGD.txt, you get an
> illustration of how eight readings of the K index through the day
> yield the daily A index. If you take the eight K index readings and
> they average to 2, this gives you an A index for the day of 7. If
> the average is around 2.333, then the A index is 9.
> 
> These periods of low geomagnetic activity are great for 160 and 80
> meters. Atmospheric noise is also much lower than in summer, and
> periods of darkness are getting longer.
> 
> This bulletin is prepared a day earlier than usual, early Thursday
> morning West Coast time, instead of early Friday. Over the next week
> expect sunspot activity to remain low, and solar flux should hover
> around 85. Planetary A index for the next five days, October 6-10 is
> predicted at 8, 10, 5, 8 and 12. The next period of moderately
> active geomagnetic conditions is forecast for October 12, based on
> the last solar rotation.
> 
> Sgt. Korey Chandler, YI9VCQ/KA5VCQ sent an email from Iraq last week
> about propagation from that part of the world. On September 30 he
> wrote, "I just wanted to comment that I've had very good luck on
> 12-meter CW for the past week. Conditions have been solid to
> Germany, Bulgaria, Russia, and Ukraine at around 1000-1500z.
> 10-meters hasn't been as good, but 15 showed several nice openings
> to Asia and Australia. 40-meters is showing a nice start towards
> winter conditions since I'm now working stations with my low
> dipole."
> 
> The next day Korey wrote, "I normally start on whatever band
> 'should' be open and work my way up. Usually I start on whatever
> band is open and work my way higher. I, too, use W6ELprop. Of
> course, I'll throw out a few CQs on each band just to check for
> surprises. Most of the native Iraqi ops here do not know CW so Iraq
> is a hard one for me to confirm. Can you believe it? Only a few of
> the American/Coalition guys run CW. 30-meters is one of my favorite
> bands. Nothing but CW/Digital and I'm a CW lover. Over 8,000 of my
> 11,000 QSOs so far are CW. Hope to see you on the bands!"
> 
> Korey mentioned W6ELprop, which has been listed here many times
> before. Probably the best way to use it is with the predicted
> smoothed sunspot number for the month, or you can average the
> previous several days of sunspot numbers, which you can get from
> http://www.sec.noaa.gov/ftpdir/indices/DSD.txt.
> 
> If you would like to make a comment or have a tip for our readers,
> email the author at, k7ra at arrl.net.
> 
> For more information concerning radio propagation and an explanation
> of the numbers used in this bulletin see the ARRL Technical
> Information Service propagation page at,
> http://www.arrl.org/tis/info/propagation.html. An archive of past
> bulletins is found at, http://www.arrl.org/w1aw/prop/.
> 
> Sunspot numbers for September 29 through October 5 were 22, 13, 0,
> 0, 0, 15 and 31 with a mean of 11.6. 10.7 cm flux was 73.8, 72.2,
> 72.1, 74.9, 74.3, 82.7, and 81.3, with a mean of 75.9. Estimated
> planetary A indices were 6, 11, 13, 13, 7, 4 and 4 with a mean of
> 8.3. Estimated mid-latitude A indices were 5, 6, 10, 8, 5, 2 and 2,
> with a mean of 5.4.