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The K7RA Solar Update

11/16/2018

A single sunspot appeared on November 13-14, yielding a daily sunspot number of 11 over both days. The sunspot number increased to 13 on the following day, November 15. The average daily sunspot number for the reporting week (November 8-14) was 3.1, after no sunspots during the previous seven days.

Average daily solar flux rose from 67.7 to 68.5.  Average daily planetary A index declined from 12 to 8.1, while average mid-latitude A index shifted from 8.1 to 6.3.

There were no sunspots for 26 days, from October 18 to November 12.

Does this place us near the bottom of the sunspot cycle? Perhaps, or somewhere toward it. Look at sunspot numbers in 2008-2009, during the last solar minimum, and note the long periods with no sunspots:

 ftp://ftp.swpc.noaa.gov/pub/indices/old_indices/2008_DSD.txt

 ftp://ftp.swpc.noaa.gov/pub/indices/old_indices/2009_DSD.txt

Predicted solar flux over the next 45 days is 68 on November 16 through December 2, 69 on December 3-4, then 70, 69 and 69 on December 5-7, then 70 on December 8-15, 69 on December 16, then 68 on December 17-29 and 69 on December 30.

Predicted planetary A index is 5 on November 16-17, 8 on November 18, 5 on November 19-24, 8 on November 25, 5 on November 26-30, then 15 and 30 on December 1-2, 10 on December 3-4, 8 on December 5-6, 12 on December 7-9, then 10 and 8 on December 10-11, 5 on December 12-27, then 15, 30 and 10 on December 28-30.

Spaceweather.com reported November 15-16 a geomagnetic unrest prediction for November 18 or 19, although that is not reflected in the forecast in the above paragraph. But the OK1HH forecast below seems to agree with Spaceweather.com in this regard.

 

Geomagnetic activity forecast for the period November 16 through December 12, 2018 from F.K. Janda, OK1HH.

Geomagnetic field will be:

Quiet on November 16, 19, 26, 29-30, December 11-12

Quiet to unsettled on November 17, 20-21, 24, December 10

Quiet to active on November 22-23, 25, December 4-9

Unsettled to active on November 18, 27-28, December 1, 3

Active to disturbed on December 2

Solar wind will intensify on November (17-23, 30) and on December 1-3, (4-6,) 7-9, (10)

Parenthesis means lower probability of activity enhancement.

 

Steve Sacco, NN4X, in Florida reported a Wednesday morning (November 14) 10-meter opening to Europe using FT8.

 

Max White, M0VNG, sent this article about the STEREO mission and observing comet tails: https://phys.org/news/2018-11-insights-comet-tails-solar.html

 

K6TW sent info about a massive solar storm in August 1972 which triggered explosive mines laid in the sea off Vietnam: https://amp.livescience.com/64062-mines-solar-storm-1972-vietnam.html

W7WKR sent additional info on the same story: https://bit.ly/2Fr3gCs

 

The ARRL SSB Sweepstakes contest is this weekend. See http://www.arrl.org/sweepstakes for details.

 

For more information concerning radio propagation, see the ARRL Technical Information Service 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 November 8 through 14, 2018 were 0, 0, 0, 0, 0, 11, and 11, with a mean of 3.1. 10.7 cm flux was 69.5, 68.9, 69, 69.3, 68.2, 67, and 67.9, with a mean of 68.5. Estimated planetary A indices were 11, 10, 13, 7, 9, 4, and 3, with a mean of 8.1. Estimated mid-latitude A indices were 12, 6, 10, 5, 6, 3, and 2, with a mean of 6.3.

 

 



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