ARRL

ARRL Propagation Bulletin ARLP023 (1997)

SB PROP @ ARL $ARLP023
ARLP023 Propagation de K7VVV

ZCZC AP23
QST de W1AW
Propagation Forecast Bulletin 23  ARLP023
From Tad Cook, K7VVV
Seattle, WA  June 6, 1997
To all radio amateurs

SB PROP ARL ARLP023
ARLP023 Propagation de K7VVV

Average Solar flux was down about 3 points last week compared to the
previous week.  The sunspot count was down also.  Geomagnetic
conditions were stable, with the only unsettled period on June 3
when the Planetary A index was 10 and the K index rose to 4.

Over the next few weeks the solar flux should rise to around 80 by
mid month, then drift back to the mid seventies.  Geomagnetic
activity should stay stable.

Dr. George C. Rybicki, KE8YX, of the NASA Lewis Research Center
wrote to say that a recent article in a journal of the American
Geophysical Union reports that the next solar cycle is predicted to
have a mean smoothed sunspot maximum of 160, about the same as the
last cycle.  He also reports a popular theory which states that even
numbered cycles are followed by a bigger odd numbered cycle, and
this is observed without exception for the past 150 years.  The next
cycle is number 23, and he says it may be a record, like cycle 19 in
the late 1950s.

Sunspot Numbers for May 29 through June 4 were 27, 35, 29, 33, 35,
20 and 16 with a mean of 27.9.  10.7 cm flux was 75.6, 75.1, 72.5,
77.3, 76.9, 75.2 and 73.9, with a mean of 75.2, and estimated
planetary A indices were 3, 7, 9, 6, 7, 10, and 5, with a mean of
6.7.
NNNN
/EX