Topband: Geomagnetic absorption of horizontally polarized antenna signals?

[Brad Rehm]

"I wonder if anyone can offer opinions on the advantages that
vertically
polarized antennas have over horizontals on 160M related to
geomagnetic
Earth absortion?"

Tom,

There's an excellent discussion of this question in the chapter on
propagation (the first chapter) in the latest edition of ON4UN's book
on low band DXing.  It comes down to a matter of where you're located.
Verticals, he says, are the best transmitting antennas for North
American hams.  If I recall correctly, the same is not true for
Europeans.  John gives a pretty credible rationale for all this.

Brad, KV5V