ARRL

ARRL Propagation Bulletin ARLP013 (2014)

SB PROP @ ARL $ARLP013
ARLP013 Propagation de K7RA

ZCZC AP13
QST de W1AW  
Propagation Forecast Bulletin 13  ARLP013
From Tad Cook, K7RA
Seattle, WA  March 28, 2014
To all radio amateurs 

SB PROP ARL ARLP013
ARLP013 Propagation de K7RA

Solar activity increased over the past week, with average daily
sunspot numbers rising from 129 to 135.6, while average solar flux
increased by nearly 13 points to 154.3. This compares the recent
March 20-26 period with the previous seven days, March 13-19.

The latest predicted solar flux from the current 45 day forecast has
10.7 cm flux values at 145 on March 28-29, 140 on March 30 through
April 2, 135 on April 3-4, 150 and 155 on April 5-6, 160 on April
7-8, then 155, 150, 145 and 140 on April 9-12, 145 on April 13-14,
150 on April 15-17 and 145 on April 18. Solar flux peaks at 160 on
April 22 and again on May 4-5.

Predicted planetary A index is 5 on March 28 through April 8, 10 on
April 9, 5 on April 10-16, then 8, 7,7, 10 and 8 on April 17-21,
then 5 until April 25, when for three days the planetary index is 8,
on April 26-28.

OK1HH believes that the geomagnetic field will be quiet to active on
March 28, mostly quiet March 29-30, quiet to unsettled March 31,
quiet to active April 1, quiet April 2-7, quiet to active April 8,
mostly quiet April 9, quiet to unsettled April 10-11, quiet April
12, quiet to unsettled April 13, mostly quiet April 14-15, quiet on
April 16, quiet to active April 17, mostly quiet April 18-19, quiet
to active April 20-21, and quiet April 22.

OK1HH says we may see enhanced solar wind on April 8, 11, 13-14 and
20-21.

OK1HH also sent along some photos from the first day of Spring, and
they can be seen at,
https://www.dropbox.com/sh/36kbsoqzou1tdbd/ATLb7dVOu3 . You can see
the Ondrejov Observatory and an interesting sculpture (images 2-5)
which catches the sunlight at local noon on both the Autumnal and
Vernal equinox and also the Winter and Summer solstice. I believe
images 7 and 8 were photographed from the observatory deck shown in
image 9. OK1HH says the observatory is a 10 minute walk from his
home. It has a Facebook page at
https://www.facebook.com/AstronomickyUstav .

Concerning the sculpture, OK1HH wrote, "Sculpture has one vertical
and three horizontal cut notches. In places where they intersect,
sunbeam penetrates the holes in the intersection when the
astronomical equinox and the summer and winter solstice around local
noon. Sunbeam penetrated on 20-21 March 2014 around 12:07 CET."

Jon Jones, N0JK is in Oahu this week, and says he worked VK, ZL, FK
and 5W on 6 meter trans-equatorial propagation.

Bill Billingsly, N5IR of Sanger, Texas sent a report about his
experiences on 17 meters on March 23. He writes, "I rarely work SSB,
but saw HB9CVQ spotted on 18.143 MHz. I have worked Andy many times
on CW, so I called him. We had a continuous SSB QSO from 2151Z to
2334Z.  Andy was running a KW into a 3-el SteppIR at 60 ft and his
signal was mostly 59+15 with two short dips to 56. I was running 200
watts into a 2-el Yagi at 70 ft. I received about the same reports.

"I had to quit for dinner and didn't return until 0029Z. HB9CVQ was
still there at 57. I moved down to 17 meters CW and worked 8Q7TS
over the pole. He was 579 here in NTX. I went back to HB9CVQ at
0050Z and he was 59+15 again. I had just a little gray light left
outside. I called him again and he gave me a 58. Andy mentioned that
the band had taken one big dip after our earlier QSO, but soon
recovered. He had been going strong since I left for dinner.

"Happy days are here again!"

Don't forget the CQ World Wide WPX SSB Contest this weekend. The CW
portion is on May 24-25. See http://www.cqwpx.com/ for details. HF
propagation should be good.

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 the ARRL
Technical Information Service web page 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 March 20 through 26 were 137, 125, 159, 159,
132, 114, and 123, with a mean of 135.6. 10.7 cm flux was 151.3,
152.6, 154.9, 157, 158.6, 152.8, and 153.2, with a mean of 154.3.
Estimated planetary A indices were 6, 10, 6, 6, 5, 8, and 9, with a
mean of 7.1. Estimated mid-latitude A indices were 4, 10, 7, 7, 4,
7, and 7, with a mean of 6.6.
NNNN
/EX