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ARRL Propagation Bulletin ARLP004 (2012)

ARLP004 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 4  ARLP004
From Tad Cook, K7RA
Seattle, WA  January 27, 2012
To all radio amateurs 

ARLP004 Propagation de K7RA

This was another week in which average daily sunspot numbers
declined, but average daily solar flux increased.

Predicted solar flux is 120 on January 27-30, 125 on January 31
through February 2, 120 on February 3, 140 on February 4-8, 145 and
150 on February 9-10, 155 on February 11-13, 150 on February 14-19,
and 145 on February 20-23.  That's right, the long anticipated short
term solar flux peak of 165 from February 17-21 is gone. The last
forecast which still held this number was on January 23 (see and on
January 24
( it

Predicted planetary A index is 8 on January 27-28, 5 on January 29
to February 7, 8 on February 8-9, and 5 again on February 10-23.

At 0617 UTC on January 22 an impact from a coronal mass ejection
caused the high-latitude college A index to reach 38, and sparked
aurora.  The index hit 38 again on January 25.  On January 23 around
0400 UTC a powerful M9 solar flare erupted, and this was right on
the threshold of becoming an X-class flare. The CME hit Earth around
1500 UTC on January 24, causing bright aurora.

Watch a lovely video of the event: Also check this British
report: and
this one from Montreal:

As this bulletin is being written early Friday morning, sunspot
group 1408 is facing Earth directly, but it is weak. Group 1402 is
passing below the western horizon, and 1410 is coming around from
the east.

At it looks like a very active region
is all the way on the other side of the Sun, at the 180 degree

Fritz Huttelmayer, WB2QWH of Cheektowaga (Buffalo) New York wrote:
"I just wanted to give you my observations of six meters during the
contest this past weekend. I have been on six a couple of times over
the past two years, running an Icom IC-703 Plus into a 40 meter
attic dipole. I am not a serious VHF operator, as I operate mostly

"I listened in on some of the activity during the January VHF
contest. I heard a W4 in Florida exchange grid squares with a W7 in
the state of Washington. Also heard were stations from Indiana,
Nevada, Texas, etc. The band sounded more like 20 meters on a good
day. No wonder they call it 'The Magic Band.'"

Mike Schaffer, KA3JAW of Tampa, Florida sent an article about solar
flares. Read it at

Mike also commented about a recent television signal he received
from XHTV (running 64 KW) in Mexico City: "On Tuesday, January 24 a
Mexican broadcaster on television channel 4 suddenly flashed upon
the screen for about five minutes (0002-0007 UTC) due to a
Sporadic-E flash event that produced a moderately strong signal
coming in with a color carrier and audio.

"The event occurred nine hours after the Coronal Mass Ejection had
hit the Earth's magnetic field at approximately 1500 UTC.

"Mexico City is 1,205 air mile distance at 245 degrees from my
location. The best part of an Es storm is that you do not have to
park your antenna at the precise azimuth toward the transmitter
tower site.

"In my case the antenna was aimed due south at 180 degrees, which
would be 65 degrees off the main beam."

Thanks, Mike!

Ron McCollum, W7GTF of Winthrop, Washington wrote to ask if I ever
heard any theories about the stock market correlating with the
sunspot cycle.

I have heard of the stock market theory, and various other
correlations with solar activity. Every time I hear of it, I think
back to my eighth grad math class, when the text had a chapter on
correlation, causation and post hoc fallacies. To illustrate, the
book displayed a graph comparing smoothed sunspot numbers with
cardboard box production in the United States.  They seemed to track
quite closely.

K7SJB years ago swore that periods of social unrest tracked with
sunspot numbers. "Tad. Remember how much fun we had in 1968-1970?,"
Stan would insist. "And the mania in securities trading till the
1929 crash?"

I get a lot of mail asking about this sort of thing. I like to
recall a presentation by Dr. James Alcock - professor of psychology
at York University, Canada - at Skeptic's Toolbox in Eugene Oregon
about the mind as a belief engine. One of the concepts presented was
that the human brain is hard wired for correlation and belief, and
how this figures into the evolution of the brain.

This weekend is the CW portion of the CQ World Wide 160-Meter
Contest. Expect good conditions, with quiet stable geomagnetic
indicators and a temporarily declining sunspot number. You can find
details at

If you would like to make a comment or have a tip for our readers,
email the author at,

For more information concerning radio propagation, see the ARRL
Technical Information Service web page at For an explanation of the
numbers used in this bulletin, see An archive of past
propagation bulletins is at Find more good
information and tutorials on propagation at

Monthly propagation charts between four USA regions and twelve
overseas locations are at

Instructions for starting or ending email distribution of ARRL
bulletins are at

Sunspot numbers for January 19 through 25 were 117, 88, 102, 103,
108, 105, and 68, with a mean of 98.7. 10.7 cm flux was 157, 141.2,
141.6, 141, 144.3, 135.7, and 126.4, with a mean of 141. Estimated
planetary A indices were 3, 4, 6, 21, 9, 17, and 14, with a mean of
10.6. Estimated mid-latitude A indices were 1, 3, 6, 22, 7, 13, and
17, with a mean of 9.9.


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