[SFDXA] ARLP036 Propagation de K7RA

[Bill]

> SB PROP @ ARL $ARLP036
> ARLP036 Propagation de K7RA
> 
> ZCZC AP36
> QST de W1AW  
> Propagation Forecast Bulletin 36  ARLP036
> From Tad Cook, K7RA
> Seattle, WA  September 4, 2015
> To all radio amateurs 
> 
> SB PROP ARL ARLP036
> ARLP036 Propagation de K7RA
> 
> The Australian Space Forecast Centre issued a geomagnetic warning at
> 0009 UTC on September 4:
> 
> "The IMF Bz has been strongly southward over the last 3 hours (2100
> UTC on September 3 to present). However, the current solar wind
> speeds are at moderate levels, which are unfavourable to cause any
> major geomagnetic disturbance. If the solar wind speeds elevate in
> the coming 24 hours, active to minor storm conditions are possible.
> If this happens, there is chance that aurora would be visible during
> the local night hours of the 4 Sep from Tasmania and other southern
> most regions of Australia.
> 
> "Increased geomagnetic activity expected due to coronal hole high
> speed wind stream for September 4, 2015."
> 
> The IMF Bz refers to the interplanetary magnetic field:
> 
> http://spaceweather.com/glossary/imf.html
> 
> Over this reporting week, August 27 through September 2, the average
> daily sunspot number was 48.3, which is 21.4 points lower than the
> previous seven days. Similarly, average daily solar flux declined
> 22.7 points to 97.
> 
> New sunspot groups appeared on August 27, 29, 30, 31, September 1
> and 3. But activity is still very weak and the sunspots are not
> magnetically complex or strong.
> 
> Now that we are in early September, we can look at recent monthly
> averages for sunspot numbers. For May through August monthly
> averages of daily sunspot numbers were 83, 77.4, 68.5 and 61.7. As
> you can see, there has been a steady decline in activity.
> 
> For our three-month moving average of daily sunspot numbers, the
> past three months, June 1 through August 31 averaged 69.1. This is
> centered on July, 2015. For the past 12 months, the three month
> moving averages of daily sunspot numbers were 108.4, 107, 104.7,
> 107.8, 98.2, 78.1, 68.2, 72.4, 77.7, 76.3 and 69.1. According to our
> same figures, the current sunspot cycle peaked between January and
> April 2014, when the three month moving averages centered on those
> months were 138.5, 146.4, 148.2 and 129.6.
> 
> The latest predicted solar flux values for the near term from
> NOAA/USAF forecasters are 85 on September 4, 90 on September 5-8, 85
> on September 9-10, then 95 and 105 on September 11-12, 115 on
> September 13-22, then 110, 105 and 100 on September 23-25, 90 on
> September 26-28, and then bottoming out at 85 on September 29
> through October 7. Although this is a long way out, predicted flux
> values then rise to 115 on October 10-18.
> 
> Planetary A index predictions show values of 8, 10 and 9 on
> September 4-6, then 10, 12 and 9 on September 7-9, then 5 on
> September 10-11, then 12, 15 and 10 on September 12-14, then 8, 10
> and 5 on September 15-17, then 8, 20 and 10 on September 18-20, 5 on
> September 21-23, and 15, 10, 5, 8, 20 and 22 on September 24-29. A
> quiet period with planetary A index at 5 is predicted for October
> 4-8.
> 
> Petr Kolman, OK1MGW of the Czech Propagation Interest Group predicts
> geomagnetic conditions will be quiet to unsettled on September 4-5,
> mostly quiet September 6-8, quiet on September 9-10, quiet to active
> September 11-13 (with the possibility of disturbed conditions on
> September 11), quiet to unsettled September 14, quiet to active
> September 15-16 (possibly disturbed September 15), quiet to
> unsettled September 17-18, active to disturbed September 19, mostly
> quiet September 20-21, quiet to active September 22, active to
> disturbed September 23- 24, quiet to unsettled September 25, quiet
> September 26-28, mostly quiet September 29 and quiet to unsettled
> September 30.
> 
> Petr expects increased solar wind on September 10-13, 15-16, 19, and
> 22-24.
> 
> http://www.spaceweather.com reports that 156 years ago this week, on
> September 2, 1859 the huge Carrington Event occurred, the monster
> geomagnetic storm in which a billion ton CME smashed into Earth,
> setting fire to telegraph stations around the world. Check
> Spaceweather.com, using the archive feature in the upper right
> corner of the site to select September 2, 2015.
> 
> David Moore sent a link to a dramatic video from the Solar Dynamics
> Observatory of sunspot group 2403 breaking up in the past week:
> 
> https://shar.es/1vl5Yp
> 
> David sent another link about solar activity and aurora over the
> past week:
> 
> https://shar.es/1vluPQ
> 
> Slate has an animation created by stringing together a long series
> of hand drawn sunspot maps:
> 
> http://bit.ly/1hGQP4r
> 
> 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 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/.
> 
> My own archives of the NOAA/USAF daily 45 day forecast for solar
> flux and planetary A index are in downloadable spreadsheet format at
> http://bit.ly/1VOqf9B and http://bit.ly/1DcpaC5 .
> 
> Click on "Download this file" to download the archive and ignore the
> security warning about file format. Pop-up blockers may suppress
> download. I've had better luck with Firefox than Internet Explorer.
> 
> 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 27 through September 2 were 46, 52, 50,
> 50, 50, 49, and 41, with a mean of 48.3. 10.7 cm flux was 110.2,
> 109.1, 100.1, 91.6, 91, 89, and 88.2, with a mean of 97.  Estimated
> planetary A indices were 53, 43, 16, 5, 6, 6, and 7, with a mean of
> 19.4. Estimated mid-latitude A indices were 26, 28, 13, 5, 5, 7, and
> 10, with a mean of 13.4.
> NNNN
> /EX