The K7RA Solar Update

SEATTLE, WA, Dec 9, 2005--This weekend is the ARRL 10-Meter
Contest. The event this year, the one in 2006 and perhaps in 2007
will probably all have very few sunspots, but as we've discussed in
recent bulletins, sometimes 10 meters opens when we least expect
it, even in the middle of the night or very early morning hours.

Mark Madcharo, AB2IW, in Schenectady, New York, will be running
QRP in the contest this weekend and wants to remind us to check
paths from the northern to southern hemisphere. At times these
may provide the only long-distance openings. Don't be afraid to call
CQ on what sounds like a dead band. You can also check the
beacons between 28.2 and 28.3 MHz or the very useful NCDXF
beacons (also, click on "Beacon Transmission Schedule and
Status"). Ten-Ten International has a list of 10 meter beacons on
its Web page. One of the remarkable features of the NCDXF
beacons is that the timing is precisely controlled, so it is easy to tell
where a weak signal is coming from provided you know what time it
is--even if you can't copy the call sign. Also, they step through
several discrete power levels: 100 W, 10 W, 1 W and 100 mW.
Another nice thing is that their network also covers the globe for 12
meters, which can sometimes give a hint of good things to come if
10 meters is not quite open yet.

Sunspot numbers and solar flux declined as Sunspot 826 moved to
the edge of the visible solar disk. Sunspot numbers peaked after
the beginning of the month. Average sunspot numbers for the past
week (the first week of December) were almost 39 points above the
previous week, at 72.6. Geomagnetic conditions were very quiet for
the past few days. For this weekend, the predicted planetary A
index from December 9-12 is 7, 12, 10 and 5. Predicted solar flux
for today (December 9) is 85, and 80 is predicted for the following
five days.

There is a low probability of disruptive solar flares this weekend, although
conditions are
expected to be slightly unsettled compared with those of the past few days. As
this "Solar
Update" is being written, the College K index, measured in Fairbanks, Alaska,
has been zero for
sixty hours straight.

You can access an array of magnetometers in Alaska to compare current to recent
conditions.
The measurements are in NanoTeslas, which are used to calculate the more
familiar K index,
but you can get a good visual indication of relative quiet or activity. Note
that at this site you can
vary the time observed from the last 24 hours up to one month, vary the scale,
and include
readings for up to eight stations.

Geophysical Institute Prague predicts unsettled conditions for December 9 and
10, quiet to
unsettled December 11, and quiet conditions December 12-15.

David Moore sent us a SpaceRef.com article about space storms and observing
upper
atmosphere disturbances.

A personal note: Back in December 1999, propagation bulletin 52 noted that the
end of 1999
would end the ninth calendar year of writing this bulletin, and that December
marked the 17th
season the author had performed as the grandfather (a non-dancing role) in
Pacific Northwest
Ballet's production of "The Nutcracker." This year marks my 23rd season in "The
Nutcracker,"
and this month marks the completion of my 15th calendar year compiling this
propagation
forecast. When I began work on "The Nutcracker," I thought I'd be fortunate to
have the role for
a few years. With this bulletin, I thought my tenure would be just a few weeks.
Thanks to you,
the readers, and to the ballet, both have been a blast!

For more information concerning propagation and an explanation of the numbers
used in this
bulletin see the ARRL Technical Information Service Propagation page. An archive
of past
bulletins is on the ARRL Web site.

Sunspot numbers for December 1 through 7 were 79, 98, 75, 91, 85, 58 and 22,
with a mean of
72.6. The 10.7 cm flux was 98.2, 106.3, 101.3, 95.2, 91.7, 89.1, and 89, with a
mean of 95.8.
Estimated planetary A indices were 13, 12, 11, 5, 2, 3 and 0, with a mean of
6.6. Estimated
mid-latitude A indices were 12, 10, 9, 3, 2, 2 and 1, with a mean of 5.6.
(K7RA, ARRL)

dxAce
Michigan
USA