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The K7RA Solar Update

10/21/2016

Over the past reporting week (October 13-19) compared to the previous seven-day average daily sunspot number declined from 55 to 31, while average daily solar flux dropped from 101.9 to 83.4.

Planetary A index increased from 6.6 to 19.1, and average mid-latitude A index jumped from 5 to 14.

This is the opposite of what happened two weeks ago compared to last week, when A indices decreased but solar flux and sunspot numbers rose.

 

The latest prediction for solar flux (from the October 20 prediction) shows these values: 75 on October 21-23, 72 on October 24, 75 on October 25-26, 80 on October 27, 75 on October 28-29, 80 on October 30, 85 on October 31 through November 5, 90 on November 6-8, 85 on October 9-11, 80 on November 12-14, 75 on November 15-19, 70 on November 20-22, 75 on November 23-25, 80 on November 26 and 85 on November 27-30.

Predicted planetary A index is 5 on October 21, then 22, 24 and 40 on October 22-24, then 44, 40 and 22 on October 24-27, 15 on October 28-30, 25 on October 31, 12 on November 1, 5 on November 2-5, 8 on November 6, 5 on November 7-10, then 10, 24, 26, 12 and 8 on November 11-15, 5 on November 16-17, then 12 and 22 on November 18-19, 35 on November 20-22, 20 on November 23, 15 on November 24-26, 25 on November 27, 12 on November 28 and 5 from November 29 to December 2.

Petr Kolman, OK1MGW, of the Czech Propagation Interest Group sent the following geomagnetic activity forecast for the period October 21-November 16, 2016

 “Geomagnetic field will be:

Quiet on November 7-8

Mostly quiet on November 3-4, 9-11, 15-16

Quiet to unsettled on October 21, November 1-2, 5-6, 14

Quiet to active on October 22-23, 29-31, November 12-13

Active to disturbed on October 24-28

 Amplifications of the solar wind from coronal holes are expected on October 22-31, November 5-6, 11-13”

 

Here is an article about a nearby star which seems to exhibit sunspot activity: http://bit.ly/2enuNmR

 

Another solar article, but this one regarding our own Sun: http://bit.ly/2eYtKNJ

 

Reader Roger Larson, KF6IVA, of Harrison, Maine says he uses an inexpensive alternative to solar telescopes called the Sunocular. A week ago he sent this message: "You can buy a special pair of binoculars (Sunoculars, 8x32 binoculars with a special coating) that allow you to observe the Sun. I can see a big sunspot headed off to the western limb, other that the Sun is featureless."

Here is the model Roger uses: https://luntsolarsystems.com/product/sunoculars-8x32/

A week later he wrote: “The Sun was featureless yesterday. With these ‘Sunoculars’ you can make out large sunspots and therefore get an idea of how active the Sun is. I have seen specialized solar telescopes which would show more due to their higher magnification but they cost a thousand dollars plus.”

Here is a less expensive model from the same source, but I don’t know how much better the more expensive one is: https://luntsolarsystems.com/product/sunoculars-mini/

Here is the last correspondence from Roger, received just as I was completing this bulletin: "They work pretty well realizing that they are only good for observing the Sun. I imagine that you've looked at the Moon with binoculars, the Sun is roughly the same angular dimensions (30 arc minutes).  The Moon has a lot of features visible in 8 power binoculars, the Sun is featureless unless there's a large sunspot(s). Along the edge of the Moon you'll see some "rainbow" effects due to imperfections in the lens unless you look with expensive binoculars. Well there are a few of these rainbow effects visible in the Sunoculars no worse than any other binoculars I've used. The objective lens is coated with a material that allows ten-millionth (1 x10^-5) of the light to pass through. The Sun appears about as bright as a full Moon in them."

  

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 October 13 through 19 were 41, 38, 35, 25, 23, 24, and 31, with a mean of 31. 10.7 cm flux was 95.3, 92.8, 84.9, 80.9, 76.2, 77.4, and 76.5, with a mean of 83.4. Estimated planetary A indices were 43, 24, 11, 18, 20, 11, and 7, with a mean of 19.1. Estimated mid-latitude A indices were 30, 20, 8, 13, 12, 10, and 5, with a mean of 14.

 

 



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