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The K7RA Solar Update

02/17/2017

In the last reporting week (February 9-15) average daily sunspot numbers declined from 21.3 to 17.6, and average daily solar flux rose from 73.5 to 75.1. Average planetary A index dropped from 12.9 to 4.7, and mid-latitude A index from 9.9 to 2.9.


Predicted solar flux is 74 on February 17-19, then 77, 80, 83, 85 and 80 on February 20-24, 78 on February 25-26, 76 on February 27-28, 75 on March 1-2, 73 on March 3-4, 72 on March 5-7, 73 and 74 on March 8-9, 75 on March 10-11, 78 on March 12-15, 80 on March 16-18, then 82, 85 and 82 on March 19-21, 80 on March 22-23, 78 on March 24-25, 76 on March 26-27, 75 on March 28-29 and 73 on March 30-31.


Predicted planetary A index is 12, 10 and 8 on February 17-19, 5 on February 20-21, 8 and 14 on February 22-23, 10 on February 24-25, then 5, 25, 30, 25 and 20 on February 26 through March 2, 15 on March 3-5, 8 on March 6, 5 on March 7-12, then 8, 12 and 10 on March 13-15, 8 on March 16-17, 5 on March 18-20, then 10 and 15 on March 21-22, then 10 on March 23-24 and 5, 25, 30, 25 and 20 on March 25-29, and 15 on March 30 through April 1.

“Geomagnetic activity forecast for the period February 17-March 15, 2017 from F.K. Janda, OK1HH:

Geomagnetic field will be:
Quiet on February 21, 24, 26, March 8, 11-12
Mostly quiet on February 19-20, March 9-10
Quiet to unsettled February 17, March 4, 7, 13-15
Quiet to active on February 18, 25, March 3, 6
Active to disturbed on February (22-23,) 27-28, March 1-2, 5

Increases in solar wind from coronal holes are expected on February 16-17, (18-22, 26-27,) March 2-5

Remark:
- Parenthesis means lower probability of activity enhancement.”


The weekly ARRL Letter (published every Thursday online) carried a fascinating and timely article this week about the reactivation of the HAARP facility in Alaska via Professor Chris Fallen, KL3WX: http://bit.ly/2kwpB6J


The ARRL Letter also runs a weekly preview of this ARRL Propagation Bulletin. Here is the latest version of the HAARP blog: https://sites.google.com/alaska.edu/gakonahaarpoon/operations-news


The ARRL International DX CW Contest begins this evening, UTC. (http://www.arrl.org/arrl-dx)


Starting tonight is also the Novice Rig Roundup, which is an on-air activity concentrating on operating old Novice ham transmitters from the 1950s and 1960s, which were all crystal controlled and generated 75 W or less, CW only (except for AM on 2 meters). Let’s see. Where is my old DX-20?

Stations using modern rigs are welcome also. Check it out at http://novicerigroundup.com/ .

Thanks to David Moore for this, concerning a slower spinning Sun: http://to.pbs.org/2lJmPrX


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 February 9 through 15, 2017 were 15, 18, 18, 18, 16, 15, and 23, with a mean of 17.6. 10.7 cm flux was 75.4, 74, 75.7, 76.2, 74.8, 74.5, and 74.8, with a mean of 75.1. Estimated planetary A indices were 7, 8, 5, 3, 5, 2, and 3, with a mean of 4.7. Estimated mid-latitude A indices were 5, 5, 3, 2, 2, 1, and 2, with a mean of 2.9.

 

 



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