In comparing conditions before and after a solar cycle
peak, I think it's worth looking at how the sunspot
numbers build and decline around the peak. If I look
at charts of the last three cycles, it appears to my
eyes that the buildup from the trough to the peak is
more rapid than the decay in the opposite direction.
Therefore, if there is an inverse correlation between
sunspot numbers and lowband propagation (i.e. fewer
sunspots are better), one would expect conditions
generally to be poorer in the 2-3 years coming off a
peak than the 2-3 years approaching the peak. My own
observations from New England (where we tend to be more
adversely affected by high-latitude absorption than
people further south) tends to confirm this
correlation.
It is particular noteworthy that the period from 1984
to 1988 produced the best overall 160m propagation that
I have witnessed in the last 2 decades. 1986 marked
the bottom of that cycle. 1987 was a particularly good
year, as I remember many days where the JA's were in,
morning after morning--an event which has not been
repeated since.
The 160m long path at local sunset to Asia and VK6,
although relatively rare at best, exists only around
the bottom of the cycle is totally absent otherwise.
Curiously, however, the local sunrise long path to
central and southeast Asia (also relatively rare)
appears only in high sunspot years and is practically
nonexistent at the bottoms. There must be different
mechanisms at work on these two long paths.
I know the the level of activity plays a role in how we
assess propagation, but I have regularly monitored a
number of lowband "beacons" through at least 2 complete
sunspot cycles. The beacons are definitely stronger,
on average, during low sunspot years. This does not
mean we should give up around sunspot peaks--it's just
that the going gets a little tougher (again speaking
for W1-land propagation).
73, John W1FV
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