Mai 2012 - Retour ACCUEIL

Les bulletins DX et contests
34
Devant l’intérêt pour cette rubrique, nous l’étendons à la publication du bulletin DX de l’ARRL ainsi qu’aux contests.
ARLP020 Propagation Bulletin
ZCZC AP20
QST de W1AW
Propagation Forecast Bulletin 20 ARLP020
From Tad Cook, K7RA
Seattle, WA May 18, 2012
To all radio amateurs
Look at the archive on http://www.spaceweather.com.
On the upper right side of the page, it is accessed by
selecting a date on the three drop-down fields. Now step
day-by-day through the past week to see the progression
of a considerable number of sunspots. The spots are in
the Daily Sun image on the left side of the page. There
was one new sunspot group on May 10, two on May 11,
four more on May 13, and another on May 15.
Average daily sunspot numbers for the past week rose
nearly 25 points, or about 27%, to 117.3. The big day was
Monday, May 14 when the daily sunspot number jumped
to 156. This was the day after four new sunspot groups,
numbered 1481 through 1484 arrived.
Average daily solar flux rose 12 points to 131, an increase
of 10 percent.
For the near term, predicted solar flux is 135 on May 18-
20, 130 on May 21-22, 125 on May 23, 120 on May 24,
115 on May 25-31, 120 on June 1, 125 on June 2-3, 130 on
June 4, 135 on June 5-9, and 130 on June 10-12.
Projected planetary A index is 15 on May 18, 8 on May 19,
5 on May 20-22, 8 on May 23, 5 on May 24 through June
4, then 8, 12, 18, and 10 on June 5-8, 5 on June 9-11, and 8
on June 12-13.
Check out
http://www.youtube.com/watchv=yJu3a2C5zwo for a
wonderful video of sunspot group 1476 as it transits the
Sun over the week of May 5-11. The images also have a
lovely orchestral accompaniment.
If you plan to be in Washington, DC on June 5, 2012, you
may want to attend the Space Weather Enterprise Forum
2012, held at the National Press Club.
See details at
http://www.nswp.gov/swef/swef_2012.html
The "Monster Sunspot" (group 1476) is all over the news,
and on the web as well at http://www.space.com/15736-
monster-sunspot-solar-flare-satellites.html. Be sure to
follow the story all the way down the page below the
video.
A large scale photo of the spot - taken a week ago on May
QSP N°22 Mai 2012
11 - is at http://news.discovery.com/space/big-pic-sunspace-weather-sunspot-eruption-120511.html
Don't miss a National Geographic article and photo
gallery on solar activity at
http://ngm.nationalgeographic.com/2012/06/solarstorms/ferris-text
Sunspot size comparisons are all the rage this week,
including this article from Universe Today:
http://www.universetoday.com/95232/how-big-aresunspots
Jim Hadlock, K7WA of Seattle, Washington is now in a
limited antenna space, and just uses a couple of 17 meter
mobile whips pointing out horizontally from a center
feedpoint. Jim writes: "It's not that great an antenna - I
often hear west coast stations working DX that I cannot
hear myself. I check the band a couple of times a day for
activity since I'm trying to work 100 DXCC entities this
year (2012). Tuesday I worked number 50 (Scotland) and
yesterday around local noon (1718Z) I worked Brunei. In
addition to listening on the band for activity, the NCDXF
Beacons at 18.110 MHz and W1AW at 18.0975 MHz
provide a check on real-time propagation."
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.
Find more good information and tutorials on propagation
at http://myplace.frontier.com/~k9la/.
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 May 10 through 16 were 93, 102,
85, 138, 156, 125, and 122, with a mean of 117.3. 10.7 cm
flux was 130.7, 136.4, 129.5, 130.5, 130, 129 and 130.9,
with a mean of 131. Estimated planetary A indices were
12, 12, 10, 12, 6, 5, and 9, with a mean of 9.4. Estimated
mid-latitude A indices were 11, 10, 8, 10, 7, 5, and 8, with
a mean of 8.4.
NNNN