Topband: Interesting Propagation Anomaly 5/26/02 - 0030z

[Dan Robbins]

Yes, both NL7Z and I have seen similar occurences.  In our case, we have worked
VE1's coming out of the south.  Here are the similarities:  This only happens
during the summer months.  It only happens when the eastern station is around
sunrise.  One of the stations is around 60 degrees, the other around 45 degrees
latitude.  The distance between ES-VY2 and VE1-KL7 is similar.  And, finally,
there may be other stations farther south coming in direct path (W3 in one
case).  My theory is that the auroral zone or the sunlit side of the terminator
is blocking the direct path and signals are backscattered over the ocean, but I
know of no way to test this.  Whatever path it is, it does not occur frequently,
but it has happened maybe a dozen different times (that I have noticed) in the
last 20 years.   I suspect it happens more regularly than we realize because
topband activity is pretty low in the summer.

Dan KL7Y