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ARRL Propagation Bulletin ARLP043 (2002)

ARLP043 Propagation de K7VVV

QST de W1AW  
Propagation Forecast Bulletin 43  ARLP043
From Tad Cook, K7VVV
Seattle, WA  October 18, 2002
To all radio amateurs 

ARLP043 Propagation de K7VVV

Sunspots and solar flux were higher over the past week. Average
daily sunspot values increased by more than 46 points over the
previous week, and average solar flux was up by nearly 20.
Geomagnetic conditions were unsettled to active. The most active
days were Thursday and Monday (October 10th and 14th) when planetary
A indices were 23 and 26. The really quiet day was Friday, with a
planetary A index of 8 and mid-latitude A index of only 5.

Solar flux should drop over the next couple of weeks to around 140
by October 27-29, then turn up again at the end of the month. Over
the next few days, Friday though Tuesday, approximate solar flux
values are predicted around 180 to 185. The earth is currently
within a high-speed solar wind, and we could see a jump in
geomagnetic activity if the interplanetary magnetic field tilts
south. Planetary A indices are predicted around 12-15 over the next
few days, an unsettled outlook.

Last week we mentioned the book, "Storms from the Sun." Michael
Carlowicz, a science writer at the Woods Hole Oceanographic
Institution is one of the authors and wrote to say he is available
to speak at larger amateur radio club gatherings and hamfests. He is
in Massachusetts, and can most easily reach southern New Hampshire
and Vermont, most areas of Massachusetts, Connecticut, Rhode Island
and New Jersey, New York City and the Hudson Valley, District of
Columbia, Eastern Pennsylvania and Northern Virginia.

He will also be in the San Francisco Bay area December 7-12, and his
co-author, who lives in Texas, may be available to speak in Texas
and New Mexico. You can contact Michael via email at,  Also check out the excellent website
devoted to the book at, . Don't miss
the Space Weather links page.

Michael sent along this abstract from a talk he gives:

"We live within the atmosphere of a variable star, and that
atmosphere is home to some of the most bizarre and unpredictable
cosmic weather. Space weather is a range of disturbances that are
born on the Sun (flares, sunspots, coronal mass ejections), rush
across interplanetary space, and disturb Earth's environment and the
various technologies we have come to depend upon."

He goes on to say,

"If you like your electronic toys and tools--or if you work for or
invest in the companies that make them--you ought to learn something
more about your nearest star...the only one that will affect you in
your lifetime."

Sunspot numbers for October 10 through 16 were 244, 178, 171, 167,
175, 165, and 182, with a mean of 183.1. 10.7 cm flux was 171.9,
179.4, 180.4, 179.2, 181.2, 176.8, and 182.5, with a mean of 178.8.
Estimated planetary A indices were 23, 8, 11, 10, 26, 15, and 14,
with a mean of 15.3.


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