[South Florida DX Association] ARLP011 Propagation de K7RA

[Bill Marx]

 ZCZC AP11
> QST de W1AW  
> Propagation Forecast Bulletin 11  ARLP011
> From Tad Cook, K7RA
> Seattle, WA  March 18, 2005
> To all radio amateurs 
> 
> SB PROP ARL ARLP011
> ARLP011 Propagation de K7RA
> 
> During this reporting week, sunspot counts were higher while
> geomagnetic indices were lower, a nice combination for HF operators.
> Average daily sunspot counts rose nearly 25 points to 60.7, and
> average daily solar flux increased nearly 22 points to 107.8.
> 
> This is a nice time to have a few more sunspots, because we are
> approaching that magic time of the equinox. Despite the old urban
> legend, the task of balancing an upright egg does not become easier
> at the equinox, but these days are nice for HF propagation.
> Sunlight is more evenly distributed across the northern and southern
> hemispheres, and it should be completely equal this Sunday, March 20
> at 1233z. That is the moment of the vernal equinox on the first day
> of spring for the northern hemisphere, and autumnal equinox for the
> southern hemisphere.
> 
> Sean Fleming, K8KHZ sent some observations about this sunspot cycle,
> and suggested that the solar flux won't be going any lower.
> Actually we are probably a couple of years away from the bottom.
> The latest SEC prediction for smoothed 10.7 cm radio flux shows a
> smoothed value of 70 around September 2006 through April 2007. In
> the same March 9, 2005 prediction, they show the smoothed sunspot
> cycle minimum around December 2006 and January 2007.
> 
> You can see the prediction in the back of the latest Preliminary
> Report and Forecast in a PDF document at,
> http://www.sec.noaa.gov/weekly/pdf/prf1541.pdf. This same chart
> predicts a smoothed sunspot number of 22 for April 2005, but doesn't
> show the cycle rising from the bottom to a smoothed number of 21
> until December 2007. This must mean that after declining to minimum,
> the solar cycle is not expected to rise back to the current level
> until early 2008.
> 
> Remarks in a recent bulletin about the biggest sunspot cycle of all,
> Cycle 19 back in the late 1950s, drew many email message with the
> same comments from hams who were brand new in the hobby back then,
> and active on either 10 or 6-meters. Many wrote, "I thought it was
> always going to be like this!"
> 
> The outlook for the very near term is for sunspots and solar flux to
> decline very gradually from current values until March 26-29, then
> rise back to current activity around April 6-11. Geomagnetic
> conditions should be slightly unsettled for March 18-19, but
> otherwise quiet after that.
> 
> Jon Jones, N0JK sent an email about a major trans-equatorial opening
> on March 9-10 from the United States to South America on 6-meters.
> He wrote, "Here in Kansas had ZP6CW in for almost 2 hours
> (0030-0230z). I worked Doug, ZP6CW for a new one! Doug reported over
> 50 USA QSOs on 6-meters and was spotted from W1, W3, W4, W5 to W7
> (Arizona, Utah), W8, W9 and W0. CE (XQ3SIX), CX, LU and PY also
> worked many in the states."
> 
> Jon continues, "6-meter Es single and double hop Es for over 12
> hours. An amazing opening, both for the long duration Es in March
> and the TEP links to South America this far along in cycle 23's
> decline."
> 
> Marvin Bloomquist, N5AW sent in similar comments concerning the same
> 6-meter opening. In addition to ZP6CW (Paraguay), he noted XQ3SIX
> (Talagante, Chile) working many W stations, as far north as W9 and
> out west to W6/W7.
> 
> With quiet geomagnetic conditions at mid-latitudes, there were still
> periods when geomagnetic activity was strong in the Arctic. The
> College K index reading from Fairbanks Alaska reached 6 on March 14
> and again on March 17. Look at the awesome aurora photos at
> http://spaceweather.com/aurora/gallery_01mar05.htm.
> 
> If you would like to comment or have a tip, 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.
> 
> Sunspot numbers for March 10 through 16 were 70, 59, 67, 77, 49, 58
> and 45 with a mean of 60.7. 10.7 cm flux was 101.6, 104.9, 110.1,
> 113.8, 111.5, 108.2 and 104.6, with a mean of 107.8. Estimated
> planetary A indices were 13, 6, 4, 6, 21, 4 and 6 with a mean of
> 8.6. Estimated mid-latitude A indices were 10, 3, 2, 4, 12, 3 and 4,
> with a mean of 5.4.
> NNNN
> /EX
> 
>