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ARRL Propagation Bulletin ARLP043 (1998)

ARLP043 Propagation de K7VVV

QST de W1AW  
Propagation Forecast Bulletin 43  ARLP043
From Tad Cook, K7VVV
Seattle, WA  October 23, 1998
To all radio amateurs 

ARLP043 Propagation de K7VVV

Solar activity was up again last week, but not by much.  Average
sunspot numbers increased from 95 to 113.6 and average solar flux
was up from 119.7 to 125.9.  The big event of the week was a major
geomagnetic storm on Monday, when the planetary A index shot up to
52.  The planetary K index was as high as 6 and the high latitude K
index reached 7.  This was all due to a coronal mass ejection on
October 15.

Conditions should be fair for the CQ Worldwide DX Phone contest this
weekend.  There is a chance that coronal holes could disrupt
geomagnetic conditions, but on Thursday night the predicted solar
flux is around 115 for Friday through Sunday, and a planetary A
index for the same three days of 15, 12 and 10.  Beyond the weekend,
the solar flux is expected to stay around 115, then rise around
November 3, to peak near 125 on November 4 and 5.  Look for
unsettled conditions around November 3 to 6.

KB4NEW sent word about an interesting chart on the NASA Space
Science News website.  Go to, then
click on ''Oct 19: Sunspot Activity Increases.''  An article follows
which talks about Cycle 23 predictions at the Marshall Space Flight
Center, and clicking on the graph will reveal a large high
resolution chart showing actual sunspot numbers against a very
smooth predicted graph.

W2PAT sent some interesting statistics on PSK errors when detecting
data on the CHU signal on 7.355 MHz.   His records show an average
number of 43 errors on each day from October 12 to 18, but on
October 19 the errors went up to 422, the day with the big
geomagnetic storm conditions.

Sunspot Numbers for October 15 through 21 were 113, 120, 107, 136,
116, 104 and 99 with a mean of 113.6.  10.7 cm flux was 131.1, 131,
135.4, 125.9, 118.5, 121.2 and 118.3, with a mean of 125.9, and
estimated planetary A indices were 6, 4, 9, 10, 52, 17 and 23, with
a mean of 17.3.


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