ARRL

ARRL Propagation Bulletin ARLP010 (1997)

SB PROP @ ARL $ARLP010
ARLP010 Propagation de KT7H

ZCZC AP10
QST de W1AW
Propagation Forecast Bulletin 10  ARLP010
From Tad Cook, KT7H
Seattle, WA  March 7, 1997
To all radio amateurs

SB PROP ARL ARLP010
ARLP010 Propagation de KT7H

There was no change in solar flux or sunspot activity last week, as
we continue to experience the bottom of the solar cycle.  There were
some geomagnetic disturbances though, with the worst conditions on
the last day of February when the Planetary A Index reached 32 and
the highest Planetary K index was 6.

Over the next few weeks the geomagnetic field should stay
predominantly quiet, except that a recurrent coronal hole with high
speed solar wind could rotate into view around March 26 and 27.
Solar flux should stay in the low to mid seventies, with the Sun
mostly spotless.

Last week this bulletin reported that the solar flux on February 26
was 74.  A closer approximation is 73.8 for that date.  This does
not change the average flux for the week.

Sunspot Numbers for February 27 through March 5 were 0 each day with
a mean of 0.  10.7 cm flux was 73.8, 72.8, 73.5, 72.3, 74, 74 and
74.6, with a mean of 73.6.  Estimated planetary A indices for the
same period were 20, 32, 10, 12, 5, 4, and 7, with a mean of 12.9.
NNNN
/EX