B PROP ARL ARLP009
ARLP009 Propagation de K7VVV
Average sunspot numbers were
lower last week, but average solar flux
was about the same, when
compared to the previous week. Sunspot
numbers were down to 88 on
Wednesday, the lowest since January 17.
Average daily solar flux for
the months of December, January and
February were 173.6, 166.6
and 147.2, indicating a decline in
activity. Average sunspots
over the same period were 146, 143 and
131. A glance at the charts
at
http://www.wm7d.net/hamradio/solar/past_cycle.shtml
shows the
decline, with recent numbers
looking like 1999, before last year's
peak.
The next short term peak in
activity is expected around March 8,
with a solar flux of 155. Predicted
flux values for the next few
days, Friday through Monday,
are 135, 140, 145 and 150. Moderate
geomagnetic conditions are
expected for the ARRL International DX
Phone Contest this weekend,
with a planetary A index of 12 on
Saturday and 10 on Sunday. However,
this is an estimate based on the
80% chance that a full halo
coronal mass ejection from the sun on
Thursday will not have a
large effect on the earth. If it is felt,
it should be on Saturday,
and there is a small possibility of
aurora.
We are moving toward spring
conditions, which means better DX
openings between the
northern and southern hemispheres. Watch for
the upper HF spectrum to
open toward the east and south early in the
day, then peak north and
south in mid day, and then toward the west
and south toward the
evening.
Sunspot numbers for February
22 through 28 were 135, 135, 99, 111,
91, 90 and 88 with a mean of
107. 10.7 cm flux was 145.8, 145.2,
137.3, 134.9, 135.4, 130.6
and 131.8, with a mean of 137.3, and
estimated planetary A
indices were 6, 11, 5, 3, 10, 13 and 7 with a
mean of 7.9.
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