[South Florida DX Association] ARLP027 Propagation de K7RA

[Bill Marx]

SB PROP ARL ARLP027
> ARLP027 Propagation de K7RA
> 
> Solar activity was up this week.  Average daily sunspot numbers rose
> nearly 22 points from last week's average to 35.6.  Average solar
> flux rose as well, 11 points from 75.7 to 86.7.  The (moderately)
> active geomagnetic day this week was July 5, with a planetary A
> index of 19, and the college A index from the magnetometer near
> Fairbanks at 28.
> 
> The increased geomagnetic activity was due to a high-speed solar
> wind stream from a coronal hole on the sun beginning July 4.  Earth
> was vulnerable due to a south-pointing interplanetary magnetic field
> (IMF).  When the IMF points north, Earth is less vulnerable.  The
> IMF is again pointing south on July 7.  The next increase in
> geomagnetic activity is predicted for July 9.  The current
> prediction for the planetary A index for July 7-10 is 8, 10, 25 and
> 18.  Solar flux for those days is predicted at about 85.
> 
> When the solar wind stream hit earlier this week, a radio burst from
> giant sunspot 898 was recorded by Thomas Ashcraft of Lamy, New
> Mexico at 1743z on July 5.  He used receivers tuned to just above 17
> meters and just above 15 meters to produce a binaural audio
> recording best appreciated with stereo headphones.  Listen to it at
> http://www.heliotown.com/Radio_Sun_Introduction.html.  Thanks to Don
> Mayhall, N5DM for the tip.
> 
> We received more notes on 6 meters and Field Day.  Bill Baker, W5GT
> reports that his club entry from W5NOR in Oklahoma used a rotatable
> dipole on six and made 109 contacts over June 24-25.  Bill Van
> Alstyne, W5WVO of Rio Rancho, New Mexico writes of six meters on
> Field Day, ''Saturday evening saw some really nice double-hop into
> the east (NY, PA, MD, VA mostly), plus the usual single-hop path to
> the mid-way point (MO, IA, IL).  Signal strength on the east coast
> stations was very good, in some cases as good as the Midwest
> stations.  Worked a new grid square (FM09) in the WV panhandle, a
> club FD effort that decided to activate this somewhat rare grid as
> well as work the contest.  Sunday morning featured a long, strong,
> and fairly broad opening into the Midwest -- MO, IA, IL, IN. WI, MN,
> and others.  Only sporadic east coast contacts, mostly in FL''.  Bill
> is looking forward to the CQ World Wide VHF Contest, July 15-16.
> 
> Eric Hall, K9GY of Lansing, Illinois reminds us to operate the IARU
> contest this weekend and specifically work operators in the World
> Radiosport Team Championship 2006, which this time around is held in
> Florianopolis, Brazil.  You can follow the progress of the teams via
> an online scoreboard.  Check http://www.wrtc2006.com/release55.html.
> 
> If you want to work the teams in Brazil, propagation to South
> America from the Northern Hemisphere should be good this weekend.
> From California, best times should be 80 meters around 0330z and
> 0530-0900z, 40 meters 0330-1000z, 20 meters 0100-0700z, and 15
> meters 1700z-0530z, with the best bet around 2330-0430z.  Although
> not a sure bet, check for 10-meter openings 2000-0500z.
> 
> From Chicago, 80 meters looks best 0330-0900z, 40 meters 0130-0930z,
> and 20 meters 2230-0530z.  15 meters does not look promising, but
> your best bet is 2100-0400z.
> 
> From Dallas, 80 meters looks good 0230-0930z, 40 meters 0100-1000z,
> 20 meters 2230-0530z, 15 meters 1700-0200z, and perhaps 10 meters,
> best chances 1800-0400z, with stronger signals toward the end of
> that period.
> 
> From Philadelphia, 80 meters looks good 0200-0830z, 40 meters
> 0000-0730z, 20 meters 2200-0530z, and perhaps 15 meters from
> 2100-0300z.
> 
> You can work out paths from your own location using the method
> outlined in earlier bulletin ARLP014.
> 
> Read it at http://www.arrl.org/w1aw/prop/2006-arlp014.html.
> 
> Of course, for the IARU contest, you work stations all over the
> world, not just in Brazil.  See the IARU HF World Championship rules
> on the ARRL web site at
> http://www.arrl.org/contests/rules/2006/iaru.html.
> 
> The end of June brings to a close the second quarter of 2006.  This
> is a good time to review average quarterly and monthly sunspot and
> solar flux numbers.  It's a good way to spot trends.
> 
> From the first quarter of 2003 through the second quarter of 2006,
> the average daily sunspot number was 120.3, 107.3, 110.2, 99.2,
> 72.9, 71.3, 69.3, 61, 46.1, 55.7, 58, 36, 18.1 and 39.7.
> 
> The average daily solar flux for the same period was 134.3, 124.2,
> 120.8, 137.4, 111.1, 99.5, 111, 104.8, 96.4, 93.1, 93.6, 84.5, 78.5
> and 82.1.
> 
> Three-month averages should be a bit smoother than one-month
> averages, and from the numbers above you might think we already hit
> bottom on the solar cycle and began a rebound.  Although activity is
> low, we haven't seen the weeks of zero sunspots that we experienced
> about a decade ago during the last solar minimum.  Also, look at the
> monthly numbers below.  Although there was a slight uptick in
> sunspot numbers and solar flux for the last quarter, the monthly
> numbers for the three months that make up this last quarter show an
> orderly decline.
> 
> The average daily sunspot numbers for the months May 2005 through
> June 2006 were 65.4, 59.8, 68.7, 65.6, 39.2, 13, 32.2, 62.6, 26.7,
> 5.3, 21.3, 55.2, 39.6 and 24.4.  Average daily solar flux for the
> same months was 99.5 , 93.7, 96.5, 92.4, 91.9, 76.6, 86.3, 90.8,
> 83.4, 76.5, 75.5, 88.9, 80.9 and 76.5.
> 
> We now have a new forecast from NOAA Space Environment Center for
> the bottom of this solar cycle, and compared to the forecast of the
> past few years, it puts the bottom just slightly further out than
> the forecast of a few years ago, which is all we had until this
> week.
> 
> You can see it in the charts in the back of the July 4 Preliminary
> Report and Forecast, at
> http://www.sec.noaa.gov/weekly/pdf/prf1609.pdf.  Note on pages 9 and
> 10 that the table of predicted smoothed sunspot numbers put the
> minimum in January 2007, or it may be more realistic to characterize
> it as occurring between December 2006 and May 2007.  The projection
> running just one week earlier, at
> http://www.sec.noaa.gov/weekly/pdf/prf1608.pdf is the same one that
> has been out for several years.  Note the minimum sunspot numbers at
> December 2006 and January 2007.  Similar numbers for the smoothed
> solar flux, which in last week's table show a minimum from December
> 2006 through April 2007, while this week's forecast shows January
> through April 2007.  Not much difference, but a slight shift out
> into 2007, and the first update to this forecast in years.
> 
> 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, see the ARRL
> Technical Information Service at
> http://www.arrl.org/tis/info/propagation.html. For a detailed
> explanation of the numbers used in this bulletin, see
> http://www.arrl.org/tis/info/k9la-prop.html. An archive of past
> propagation bulletins is at http://www.arrl.org/w1aw/prop/ .
> 
> Sunspot numbers for June 29 through July 5 were 35, 38, 36, 34, 38,
> 40 and 28 with a mean of 35.6. 10.7 cm flux was 85.5, 86.1, 85.5,
> 87.1, 85.9, 92, and 84.7, with a mean of 86.7. Estimated planetary A
> indices were 12, 8, 5, 2, 4, 13 and 19 with a mean of 9. Estimated
> mid-latitude A indices were 8, 7, 3, 1, 2, 11 and 18, with a mean of
> 7.1.
> NNNN
> /EX
> 
>