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The K7RA Solar Update

02/28/2020

Still no sunspots through all of February, except for the first day of the month. I keep watching for possible sunspot activity over the solar horizon on  https://stereo.gsfc.nasa.gov/ . Recently I noticed a promising looking white area, and in the past few days at Spaceeweather.com they pointed out two new regions just over the horizon.

As of Thursday night, both areas still appear to be transitioning over the horizon at -90 degrees shown on the STEREO monitor at the above URL. But so far nothing in the daily 45 day forecast of solar flux shows any associated increase related to this.

Average daily solar flux changed slightly from 70.9 to 70.5 over the recent week, and geomagnetic indicators remained quiet.

Predicted solar flux over the next 45 days is 70 on February 28 through March 3, and 71 on March 4 through April 12.

Predicted planetary A index is 5 on February 28 through March 3, then 12, 12 and 8 on March 4-6, 5 on March 7-14, then 10, 8, 10, 8, 5, 10 and 8 on March 15-21, then 5, 8, 12 and 10 on March 22-25, 5 on March 26-30, then 20, 15 and 8 on March 31 through April 2, then 5 on April 3-12.

Geomagnetic activity forecast for the period February 28 to March 25, 2020 from F.K. Janda, OK1HH.

Geomagnetic field will be
quiet on: March 11-14
quiet to unsettled on: March 1-3, 15, 18, 21, 23-25
quiet to active on: February (28-29), March 7-10, 19-20, 22
unsettled to active on: March 4-6, 16-17
active to disturbed: NONE!

Solar wind will intensify on: February (28 -29), March 5-7, (17-22).

Parenthesis means lower probability of activity enhancement.

Interesting article about the Kodaikanal observatory in India with some nice butterfly diagrams and charts of daily sunspot area: https://bit.ly/39dyFD6

Next weekend the Apache Point Observatory in Sunspot, New Mexico hosts an open house: https://bit.ly/2I53GwO

Solar activity and whale navigation: https://bit.ly/2Pw3KtK

And the New York Times weighs in: https://www.nytimes.com/2020/02/25/science/whales-sunspots.html

Mike Schaffer, KA3JAW, in Easton, Pennsylvania monitors 11 meters for evidence of sporadic-e skip. On Monday, February 24 he reports: “Sporadic-e lasted for nearly three hours from 9:58 AM (1458 UTC) to 12:49 PM (1749 UTC).

“At first, stations were coming from the west with signals from Illinois, Indiana, and Ohio. The furthest was a station in Chicago at 650 miles.

“Half-way into the activity, at around 11:33 am (1633 UTC), sporadic-e changed directions toward the south with signals arriving from Mississippi, Florida, Georgia, Tennessee, and Kentucky. The furthest signal during that round came from Jackson, Mississippi at 1013 miles.”

If you would like to make a comment or have a tip for our readers, email the author at k7ra@arrl.net.

For more information concerning radio propagation, see http://www.arrl.org/propagation and 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 February 20 through 26, 2020 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 70.8, 71.2, 70.2, 70.1, 70.2, 70.6, and 70.1, with a mean of 70.5. Estimated planetary A indices were 8, 14, 9, 5, 4, 3, and 4, with a mean of 6.7. Middle latitude A index was 5, 10, 7, 4, 3, 3, and 3, with a mean of 5.

 



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