[SFDXA] ARLP049 Propagation de K7RA

[Bill M]

> SB PROP @ ARL $ARLP049
> ARLP049 Propagation de K7RA
> 
> ZCZC AP49
> QST de W1AW  
> Propagation Forecast Bulletin 49  ARLP049
> From Tad Cook, K7RA
> Seattle, WA  December 15, 2017
> To all radio amateurs 
> 
> SB PROP ARL ARLP049
> ARLP049 Propagation de K7RA
> 
> Over the past reporting week (December 7-13) we saw three days with
> zero sunspots (December 8, 9 and 13). Compared to the previous seven
> days, average daily sunspot number more than doubled to 6.9 and
> average daily solar flux increased from 69.6 to 71.
> 
> One new sunspot group (2691) emerged on December 10 with one spot,
> which increased to three over the next two days, but by December 13
> it had all disappeared. You can see it at,
> http://www.solarham.net/regions/2691.htm .
> 
> According to Spaceweather.com as of Thursday, December 14, for all
> of 2017 so far 27% of all days have had no visible sunspots.  They
> say the blank Sun count for 2016 was 9%. They show the count for
> 2009 at 71%.
> 
> Current sunspot and solar flux numbers are low enough that coverage
> for local 75 and 80 meter nets suffers, because they are too low to
> reflect back high angle radiation at 3.5-4 MHz.
> 
> Geomagnetic numbers were low, with average planetary A index
> declining from 11.6 to 7.4, and mid-latitude A index from 8.1 to
> 5.6.
> 
> The latest forecast from USAF and NOAA shows solar flux at 72 on
> December 15-17, 75 on December 18-21, 74 on December 22-23, 72 on
> December 24-26, 70 on December 27 through January 5, 72 on January
> 6-8, 74 on January 9-19, 72 on January 20-22, and 70 on January
> 23-28.
> 
> Predicted planetary A index is 5 on December 15-16, then 12, 20, 18,
> 10 and 8 on December 17-21, 5 on December 22-26, 12 and 8 on
> December 27-28, 5 on December 29-30, then 10, 26, 14 and 10 on
> December 31 through January 3, 5 on January 4-6, then 14, 16, 14 and
> 8 on January 7-10, 5 on January 11-12, then 8, 25, 10, 8 and 8 on
> January 13-17, 5 on January 18-22, then 12 and 8 on January 23-24, 5
> on January 25-26 and 10 and 26 on January 27-28.
> 
> The above predictions are updated daily, usually after 2115-2130z,
> and are located at, ftp://ftp.swpc.noaa.gov/pub/forecasts/45DF/ .
> 
> F.K. Janda, OK1HH sent his geomagnetic activity forecast for the
> period December 15 to January 10, 2017:
> 
> "Geomagnetic field will be:
> Quiet on December 23-24, 26, January 5-6,
> Mostly quiet on December 16, 25, January 4,
> Quiet to unsettled on December 15, 17, 30, January 7-8
> Quiet to active on December 20-22, 27-29, 31, January 3, 9
> Active to disturbed on December 18-19, January 1-2, 10
> 
> "Amplifications of the solar wind from coronal holes are expected on
> December (17,) 18-22, (24-25, 30-31,) January 1-3, (4,) 5-7, (8)
> 
> "Parenthesis means lower probability of activity enhancement."
> 
> A pretty good post about aurora appeared in an adult Scouting blog
> at, https://blog.scoutingmagazine.org/2017/12/12/northern-lights/ .
> It showed nice images of aurora too, although it is important to
> keep in mind that the most beautiful and dramatic images are
> captured using long exposure times.
> 
> This post makes a common error when it says, "The Sun cycles in
> about 11 years of increased sunspots," when actually the period of
> increased sunspots is somewhere in the middle of this period. Eleven
> years is the approximate total length of a typical solar cycle,
> which may vary from 9 to 14 years, from one solar minimum to the
> next.
> 
> English usage nitpick: Instead of "and can hurdle solar particles
> toward Earth," I think the word the author had in mind was "hurtle."
> They sound mostly the same, so are often confused, according to
> http://grammarist.com/spelling/hurdle-hurtle/
> 
> The post contains a very useful link to a frequently updated
> forecast of aurora at,
> http://www.swpc.noaa.gov/products/aurora-30-minute-forecast .
> 
> Reports from last weekend's ARRL 10-Meter Contest indicate terrible
> conditions. I operated briefly on Saturday, hearing nothing but
> local area CW signals, no phone.
> 
> Checking the ARRL contest soapbox at,
> http://www.arrl.org/contests/soapbox indicates nobody used a dupe
> sheet or duplicate checking program because activity was so low,
> they didn't need one.
> 
> KE2SX in North Carolina (FM05sw) commented that he worked only 6
> "very local stations" over the whole weekend, all in his state so
> there was only a single multiplier, his own state.
> 
> K2AF reported from New Jersey (FN20nu) that this is his favorite
> contest, but "This year, I am hoping that I got both station's calls
> right so that I don't end up with a negative score."
> 
> The latest space weather news from Dr. Tamitha Skov:
> 
> https://www.youtube.com/watch?v=KY0l83t1VL0
> 
> JT8 (the latest mode from K1JT) seems to have taken the amateur
> radio service by storm in recent months, with an amazing rate of
> acceptance due to its weak signal capabilities and easy
> implementation.
> 
> But check out this blog post from NW7US regarding the Olivia mode,
> which facilitates actual conversations via weak signals:
> 
> http://bit.ly/2kuX7aS
> 
> NW7US is a propagation expert who among other things writes and
> edits the monthly CQ Magazine Propagation column.
> 
> 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 web page at,
> http://arrl.org/propagation-of-rf-signals. For an explanation of
> 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 December 7-13, 2017 were 11, 0, 0, 11, 13, 13,
> and 0, with a mean of 6.9. 10.7 cm flux was 67.9, 69.9, 71.1, 72,
> 72.3, 71.4, and 72.1, with a mean of 71. Estimated planetary A
> indices were 10, 5, 4, 3, 10, 13, and 7, with a mean of 7.4.
> Estimated mid-latitude A indices were 9, 4, 3, 2, 8, 9, and 4, with
> a mean of 5.6.
> NNNN
> /EX