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K7RA's Solar Report

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Last update: Friday, 26-Feb-2021 04:05:57 GMT

SB PROP @ ARL $ARLP009
ARLP009 Propagation DE K7RA
QST DE W1AW
Propagation Bulletin 9 ARLP009 From Tad Cook, K7RA
Seattle, Washington February 26, 2021
To all radio amateurs

Sunspots have returned, and solar activity increased on every day in this reporting week. Thursday evening, Spaceweather.com reported that in a single day, sunspot group AR2804 has doubled in size.

The total sunspot area was 200 millionths of a solar hemisphere, a level not seen since the end of last year. It actually took two days to double, Tuesday through Thursday covering 100, 150 and then 200.

Average daily sunspot number increased from zero to 19.6, while average daily solar flux rose from 72 to 75.7. Geomagnetic activity was also higher, with average daily planetary A index increasing from 7.7 to 16, and average daily mid-latitude A index rose from 5.6 to 12.4.

Predicted solar flux for the next 30 days is 80 on February 26-28, 78 on March 1, 74 on March 2-5, 73 on March 5-6, then 74, 70, 74 and 76 on March 7-10, then 72, 71, 72 and 70 on March 11-14, then 71, 72, 71, 73, 76 and 75 on March 15-20, 72 on March 21-22, 76 on March 23-24, then 74 and 73 on March 25-26, then 74 and 73 again on March 27-28. . Predicted planetary A index is 5 on February 26 through March 1, then 18 and 12 on March 2-3, then 10, 8 and 15 on March 4-6, 5 on March 7-11, then 15, 10 and 5 on March 12-14, then 15, 5, 8 and 18 on March 15-18, 20 on March 19-20, then 10 and 8 on March 21-22, and 5 on March 23-27.

Check this out, something called Automated Solar Activity Prediction:

http://spaceweather.inf.brad.ac.uk/asap/

While this looks interesting, so far I have been unable to download any data more recent than 2009 or 2011.

Geomagnetic activity forecast for the period February 26 til March 23, 2021 from F.K. Janda, OK1HH and the Czech Propagation Interest Group, compiling these geomagnetic activity weekly forecasts since January 1978.

"Geomagnetic field will bequiet on: March 9-10, 14 quiet to unsettled on: February 26-27, March 4-5, 13, 16-17, 20 quiet to active on: (February 28,) March 2-3, 7-8, 11, 15, 18-19, 21-23 unsettled to active: March (1,) 6, 12 active to disturbed: nothing expected

Solar wind will intensify on: February 28, March 1-3, (4-9, 12,) 13, (14, 16-22,)

Parenthesis means lower probability of activity enhancement. Predictability of changes remains low, as there are very ambiguous indications.'D

Tamitha Skov, WX6SWW posted this new video a few days ago:

https://youtu.be/bNxuOtBMN2s

Forbes magazine describes recent space weather as "spicy'D:

https://bit.ly/2NJKYBj

Prediction from a few days back, with interesting graphics:

https://bit.ly/37OtJFI

British tabloid describes a solar "canyon of fire'D, but you need to page through a lot of other stuff to read the whole article.

https://bit.ly/3qWQcYY

Ken Brown, N4SO (EM50tk) wrote on February 19:

"One measure of propagation is to call CQ at a very low power on CW and look for returns on Reverse Beacon Network. This was done with the K2 power control knob ALL the way down, and on an Elecraft W1 power meter reading 100 mw on the lowest scale. Several CQ's were called.

KD7YZ responded with a single spot. Location: GREENUP, KY (EM88ll). QRPp 100 mw Mode: CW Band: 30m Response from KD7YZ Date and Time of test: 18 wpm 1747z 14 Feb"

This weekend is the CQ 160 meter SSB Contest:

https://www.cq160.com

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/.

Instructions for starting or ending email distribution of ARRL bulletins are at http://arrl.org/bulletins .

Sunspot numbers for February 18 through 24, 2021 were 12, 12, 12, 11, 26, 31, and 33, with a mean of 19.6. 10.7 cm flux was 71.1, 72.9, 76.4, 75.3, 75.9, 78.1, and 80.5, with a mean of 75.7. Estimated planetary A indices were 5, 17, 20, 20, 17, 12, and 21, with a mean of 16. Middle latitude A index was 2, 13, 15, 18, 13, 10, and 16, with a mean of 12.4. NNNN


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