ARRL

ARRL Propagation Bulletin ARLP011 (2003)

This is a multi-part message in MIME format.

------_=_NextPart_001_01C2ED8B.9683153F
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

SB PROP @ ARL $ARLP011
ARLP011 Propagation de K7RA

ZCZC AP11
QST de W1AW =20
Propagation Forecast Bulletin 11  ARLP011
From Tad Cook, K7RA
Seattle, WA  March 14, 2003
To all radio amateurs=20

SB PROP ARL ARLP011
ARLP011 Propagation de K7RA

Average daily solar flux and sunspot numbers were up again this
week. Average daily sunspot numbers, which were up nearly 50 points
last week compared to the previous week, this week rose nearly 70
points compared to last week. Average daily solar flux was up 30
points last week and over 7 points this week. Solar flux is expected
to decline to just above 100 from March 20-24, around the time of
the solar equinox.

There is a large coronal hole responsible for a solar wind stream
heading our way. It could result in some active geomagnetic
conditions this weekend, but so far only unsettled conditions are
predicted through Sunday, with a planetary A index around 15.

Note that the vernal equinox is coming up this week, a wonderful
time for HF propagation. On the first day of spring the night and
day will be exactly 12 hours each, all over the world, from the
equator to the poles. Over the winter in the northern hemisphere,
signals traveling to the southern hemisphere have to deal with
summertime propagation modes.

At either equinox (autumnal or vernal) the whole earth is blessed
with an even distribution of solar radiation.

For more information about propagation and an explanation of the
numbers used in this bulletin, see the Propagation page on the ARRL
Web site at, http://www.arrl.org/tis/info/propagation.html and
especially the article "The Sun, the Earth, the Ionosphere," by Carl
Luetzelschwab, K9LA.

Sunspot numbers for March 6 through 12 were 132, 191, 203, 224, 214,
142, and 109, with a mean of 173.6. 10.7 cm flux was 150.3, 149.9,
148.3, 152.7, 143.7, 141.5, and 138, with a mean of 146.3. Estimated
planetary A indices were 25, 14, 9, 11, 16, 13, and 9, with a mean
of 13.9.
NNNN
/EX


------_=_NextPart_001_01C2ED8B.9683153F
Content-Type: text/html;
	charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; =
charset=3Diso-8859-1">
<META NAME=3D"Generator" CONTENT=3D"MS Exchange Server version =
6.0.6249.1">
<TITLE>ARLP011 Propagation de K7RA</TITLE>
</HEAD>
<BODY>
<!-- Converted from text/plain format -->

<P><FONT SIZE=3D2>SB PROP @ ARL $ARLP011</FONT>

<BR><FONT SIZE=3D2>ARLP011 Propagation de K7RA</FONT>
</P>

<P><FONT SIZE=3D2>ZCZC AP11</FONT>

<BR><FONT SIZE=3D2>QST de W1AW&nbsp; </FONT>

<BR><FONT SIZE=3D2>Propagation Forecast Bulletin 11&nbsp; ARLP011</FONT>

<BR><FONT SIZE=3D2>From Tad Cook, K7RA</FONT>

<BR><FONT SIZE=3D2>Seattle, WA&nbsp; March 14, 2003</FONT>

<BR><FONT SIZE=3D2>To all radio amateurs </FONT>
</P>

<P><FONT SIZE=3D2>SB PROP ARL ARLP011</FONT>

<BR><FONT SIZE=3D2>ARLP011 Propagation de K7RA</FONT>
</P>

<P><FONT SIZE=3D2>Average daily solar flux and sunspot numbers were up =
again this</FONT>

<BR><FONT SIZE=3D2>week. Average daily sunspot numbers, which were up =
nearly 50 points</FONT>

<BR><FONT SIZE=3D2>last week compared to the previous week, this week =
rose nearly 70</FONT>

<BR><FONT SIZE=3D2>points compared to last week. Average daily solar =
flux was up 30</FONT>

<BR><FONT SIZE=3D2>points last week and over 7 points this week. Solar =
flux is expected</FONT>

<BR><FONT SIZE=3D2>to decline to just above 100 from March 20-24, around =
the time of</FONT>

<BR><FONT SIZE=3D2>the solar equinox.</FONT>
</P>

<P><FONT SIZE=3D2>There is a large coronal hole responsible for a solar =
wind stream</FONT>

<BR><FONT SIZE=3D2>heading our way. It could result in some active =
geomagnetic</FONT>

<BR><FONT SIZE=3D2>conditions this weekend, but so far only unsettled =
conditions are</FONT>

<BR><FONT SIZE=3D2>predicted through Sunday, with a planetary A index =
around 15.</FONT>
</P>

<P><FONT SIZE=3D2>Note that the vernal equinox is coming up this week, a =
wonderful</FONT>

<BR><FONT SIZE=3D2>time for HF propagation. On the first day of spring =
the night and</FONT>

<BR><FONT SIZE=3D2>day will be exactly 12 hours each, all over the =
world, from the</FONT>

<BR><FONT SIZE=3D2>equator to the poles. Over the winter in the northern =
hemisphere,</FONT>

<BR><FONT SIZE=3D2>signals traveling to the southern hemisphere have to =
deal with</FONT>

<BR><FONT SIZE=3D2>summertime propagation modes.</FONT>
</P>

<P><FONT SIZE=3D2>At either equinox (autumnal or vernal) the whole earth =
is blessed</FONT>

<BR><FONT SIZE=3D2>with an even distribution of solar radiation.</FONT>
</P>

<P><FONT SIZE=3D2>For more information about propagation and an =
explanation of the</FONT>

<BR><FONT SIZE=3D2>numbers used in this bulletin, see the Propagation =
page on the ARRL</FONT>

<BR><FONT SIZE=3D2>Web site at, <A =
HREF=3D"http://www.arrl.org/tis/info/propagation.html">http://www.arrl.or=
g/tis/info/propagation.html</A> and</FONT>

<BR><FONT SIZE=3D2>especially the article &quot;The Sun, the Earth, the =
Ionosphere,&quot; by Carl</FONT>

<BR><FONT SIZE=3D2>Luetzelschwab, K9LA.</FONT>
</P>

<P><FONT SIZE=3D2>Sunspot numbers for March 6 through 12 were 132, 191, =
203, 224, 214,</FONT>

<BR><FONT SIZE=3D2>142, and 109, with a mean of 173.6. 10.7 cm flux was =
150.3, 149.9,</FONT>

<BR><FONT SIZE=3D2>148.3, 152.7, 143.7, 141.5, and 138, with a mean of =
146.3. Estimated</FONT>

<BR><FONT SIZE=3D2>planetary A indices were 25, 14, 9, 11, 16, 13, and =
9, with a mean</FONT>

<BR><FONT SIZE=3D2>of 13.9.</FONT>

<BR><FONT SIZE=3D2>NNNN</FONT>

<BR><FONT SIZE=3D2>/EX</FONT>
</P>

</BODY>
</HTML>
------_=_NextPart_001_01C2ED8B.9683153F--