[SFDXA] ARLP033 Propagation de K7RA

[Bill Marx]

> 
> SB PROP @ ARL $ARLP033
> ARLP033 Propagation de K7RA
> 
> ZCZC AP33
> QST de W1AW  
> Propagation Forecast Bulletin 33  ARLP033
> From Tad Cook, K7RA
> Seattle, WA  August 16, 2013
> To all radio amateurs 
> 
> SB PROP ARL ARLP033
> ARLP033 Propagation de K7RA
> 
> Again this week, solar activity was unchanged, with average daily
> sunspot numbers slipping from 85.4 to 85, and average daily solar
> flux increasing 4.4 points to 111.7.  Geomagnetic conditions were
> stable.
> 
> The latest solar flux prediction from USAF/NOAA has flux values of
> 125 on August 16, 130 on August 17-18, 120 on August 19-20, 110 on
> August 21-23, 105 on August 24, 110 on August 25-26, 115 on August
> 27-29, 110 on August 30, 105 on August 31 through September 6, then
> 110 and 115 on September 7-8 and 120 on September 9-11.
> 
> Predicted planetary A index is 12 and 8 on August 16-17, 5 on August
> 18-19, then 12 and 15 on August 20-21, 8 on August 22-23, 5 on
> August 24-30, then 12, 15, and 10 on August 31 through September 2,
> and 5 on September 3-7.
> 
> OK1HH issues his own weekly geomagnetic activity forecast, and he
> sees mostly quiet geomagnetic conditions August 16-17, quiet to
> active August 18, quiet on August 19, mostly quiet August 20, quiet
> August 21, active to disturbed August 22, quiet to unsettled August
> 23, quiet to active August 24, quiet to unsettled August 25-28,
> quiet August 29-30, active to disturbed September 1, quiet to
> unsettled September 2, quiet on September 3-5, mostly quiet
> September 6-8, active to disturbed September 9, quiet to active
> September 10, and active to disturbed September 11.  OK1HH says "a
> positive storm phase" is expected August 22, and a growing solar
> wind may cause remarkable changes in the magnetosphere and
> ionosphere on August 16, and 21-22, and September 1-2, 6-7, and 11.
> 
> At 0318 UTC on August 16, the Australian Space Forecast Centre
> issued a geomagnetic warning, saying a high speed wind stream is
> spewing from a coronal hole.  Unsettled to active geomagnetic levels
> are expected today, August 16, and minor storm levels are possible.
> 
> Scientific American has a 60 second podcast explaining why the
> changing magnetic polarity of the sun is nothing to worry about.
> Listen at 
> http://www.scientificamerican.com/podcast/episode.cfm?id=solar-magnetic-field-flip-poses-no-13-08-15.
> 
> We get our solar flux data directly from the observatory in
> Penticton, British Columbia where they measure and report the
> numbers.  It has been available at
> ftp://ftp.geolab.nrcan.gc.ca/data/solar_flux/daily_flux_values/fluxtable.txt
> but this week that server seemed unreachable.  I poked around for
> quite some time and finally found the same data in html rather than
> plain text format at
> http://www.spaceweather.ca/data-donnee/sol_flux/sx-5-flux-eng.php.
> 
> Al Kaiser, N1API of Meriden, Connecticut asked, "If you have two
> flares at the same time from two different sunspot areas on the sun,
> do they add up to give a bigger class of flare, or just end up as
> one longer event?"
> 
> They are counted and rated separately.  And if the flares are on
> different areas of the sun, they are probably pointing in different
> directions, so one or both might not affect earth.
> 
> Randy Crews, W7TJ of Spokane, Washington has long been fascinated by
> the idea that the current solar cycle 24 may turn out to have two
> peaks, like the last few cycles.  He writes, "There have been
> several predictions that cycle 24 might have a second peak.  Well
> maybe - maybe not.  Cycle 21 had a definite single peak:  November
> of 1979.  Cycle 22 had two peaks:  September of 1989 and January of
> 1991.  Cycle 23 also had two peaks:  April/July of 2000 and December
> of 2001.  K9LA presented some interesting analysis regarding the
> declining magnetic strength of sunspots since 1995 and especially
> cycle 24."  See 
> http://myplace.frontier.com/%7ek9la/Looking_Ahead_To_Solar_Cycle_25.pdf
> 
> Randy continues, "Anyone who brings up a NASA photo of sunspots
> during Cycle 21-23 will see many large magnetically complex sunspots
> vs. Cycle 24's 'freckles' of small magnetically simple spots.  So we
> MAY see a second peak IF the magnetic strength of the sunspots
> holds, or better yet increases.  If not, a second peak is doubtful,
> and chances are the peak of activity has passed (as defined by the
> average monthly solar flux and average monthly sunspot count).  The
> Sun is always full of surprises.  During the CQWW Contest of October
> 2003 the solar flux punched up to 290!"
> 
> Ah, Randy, wouldn't that be nice to see again!  In fact, your
> current author's stewardship of this bulletin began in 1991, not
> because of any particular expertise regarding astrophysics, but due
> to a similar sudden burst of solar activity, which happened to
> coincide with the former (and only other) author of this bulletin
> becoming too ill to write (see http://oldqslcards.com/W1HDQ.pdf).
> The event was Thursday, January 31, 1991 when the solar flux reached
> 357.  Someone needed to write about this.  I had no idea when I
> alerted folks in Newington that it would be me.
> 
> For more information concerning radio propagation, see the ARRL
> Technical Information Service at
> http://arrl.org/propagation-of-rf-signals.  For an explanation of
> the numbers used in this bulletin, see
> http://arrl.org/the-sun-the-earth-the-ionosphere.  An archive of
> past propagation bulletins is at
> http://arrl.org/w1aw-bulletins-archive-propagation.  More good
> information and tutorials on propagation are at http://k9la.us/.
> 
> Monthly propagation charts between four USA regions and twelve
> overseas locations are at http://arrl.org/propagation.
> 
> Instructions for starting or ending email distribution of ARRL
> bulletins are at http://arrl.org/bulletins.
> 
> Sunspot numbers for August 8 through 14 were 90, 51, 76, 90, 85, 98,
> and 105, with a mean of 85. 10.7 cm flux was 104.4, 103.6, 102.5,
> 110.4, 114.1, 122, and 125.2, with a mean of 111.7.  Estimated
> planetary A indices were 5, 9, 6, 6, 6, 9, and 10, with a mean of
> 7.3.  Estimated mid-latitude A indices were 4, 11, 7, 7, 6, 9, and
> 9, with a mean of 7.6.
> NNNN
> /EX