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ARRL Propagation Bulletin ARLP001 (2009)

ARLP001 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 1  ARLP001
From Tad Cook, K7RA
Seattle, WA  January 2, 2009
To all radio amateurs 

ARLP001 Propagation de K7RA

2008 was a year of very low solar activity.  Over forty percent of
this year's propagation bulletins reported zero sunspots for their
respective weeks.  The average daily sunspot number for the year was
4.7, and in 2007 it was 12.8.

The yearly averages of daily sunspot numbers for 1999-2008 were
136.3, 173, 170.3, 176.6, 109.2, 68.6, 48.9, 26.1, 12.8 and 4.7.

Two years ago we wrote, ''This is the first bulletin of 2007, the
year we'll likely see the end of sunspot cycle 23, the beginning of
cycle 24, and the minima between cycles''.

One year ago in the first bulletin of 2008 we noted the same quote
from the previous year, and wrote ''Now a year later we might say the
same about 2008''.

This is probably still true for past year, because since early 2008
we saw cycle 24 spots, and what looks like a slow increase in
activity toward the end of the year, although a week of sunspots at
the end of December would have helped to sustain the upturn.

We've been looking at a three month moving average of sunspot
numbers, and the average for October-December, centered on November,
was 4.4, about the same as the number 4.5 centered on October.

Here are the 3-month sunspot number averages since early 2007:

Jan 07 22.7 
Feb 07 18.5 
Mar 07 11.2 
Apr 07 12.2 
May 07 15.8 
Jun 07 18.7 
Jul 07 15.4 
Aug 07 10.2 
Sep 07  5.4 
Oct 07  3.0 
Nov 07  6.9 
Dec 07  8.1 
Jan 08  8.5 
Feb 08  8.4 
Mar 08  8.4 
Apr 08  8.9 
May 08  5.0
Jun 08  3.7 
Jul 08  2.0 
Aug 08  1.1 
Sep 08  2.5 
Oct 08  4.5 
Nov 08  4.4

For those readers who track the solar cycle using Scott Craig's
Solar Data Plotting Utility, there is a new data file on his website
containing 20 years of data, from January 1, 1989 through December
31, 2008.

The program can automatically suck up the data from the text of our
bulletins.  You can download the software for Windows and the update
from the WA4TTK web site at
The updated data file is available directly from

Mike Hoteling, KD7IBE of Colville, Washington wrote ''Just want to
report some good propagation from northeastern Washington on 160
meters late at nite.  These quiet sunspot conditions offer some
unique opportunities.  QSO into Wyoming and Texas complete with QSL
cards with the century club on 1892 kHz with 100 watts into a 75
meter dipole at 35 feet.  Don't be afraid to give it a try.''

Elwood Downey, WB0OEW of Socorro, New Mexico along with many other
readers called attention to recent news from NASA that the
ionosphere is now at lower elevation than in the past.  I suppose
this means that worldwide shortwave signals might not propagate as
far.  Read the article that Elwood sent at

A number of readers, including Norm Priebe, W7ISD of Alexandria,
Minnesota sent in links to articles about a big hole in our earth's
magnetic field.  Read about it at  
The magnetosphere helps protect us from solar wind, so if these findings 
are correct, it wouldn't take strong space weather to trigger aurora.

The local newspaper in Homer, Alaska ran an article this week about
aurora borealis, which often can be seen from Homer.  Read it at

Dave Deatrick, WA8OLD was mentioned in ARLP051 back in December,
2006, when he told about the fun he was having on 40 meters with a
shortened dipole in a vee configuration at 30 feet.  He wrote again
on December 20, 2008 to report more fun from the far north of
Michigan with the same antenna, and about 4.8 db more power (300
watts vs. 100 watts).  He lives about a mile from the Canadian
border at Sault Ste Marie, and writes ''40 CW has been good lately,
especially from about 1000 to 1200 GMT to Caribbean and South
America.  Just worked H6VA at 1155 this morning, December 20.  Also
was able to work a AH6 same time period during CQ WW CW test''.

Finally, nothing to do with propagation, but check out this link to
a historical page dedicated to the Novice license:

For more information concerning radio propagation, see the ARRL
Technical Information Service at  For a detailed
explanation of the numbers used in this bulletin, see  An archive of past
propagation bulletins is at

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

Instructions for starting or ending email distribution of this
bulletin are at

Sunspot numbers for December 25 through 31 were 0, 0, 0, 0, 0, 0,
and 0 with a mean of 0.  10.7 cm flux was 69.3, 69.2, 69.4, 69.8,
69.8, 68.5, and 69.3 with a mean of 69.3.  Estimated planetary A
indices were 3, 1, 1, 2, 0, 1 and 10 with a mean of 2.6.  Estimated
mid-latitude A indices were 2, 2, 1, 1, 1, 1 and 8 with a mean of


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