There is no ground wave
propagation of horizontally polarized waves. Thus, a horizontally
polarized receiving antenna ignores much of the available noise.

There can be exceptions to this though. There is a horizontal "space
wave" and it can cause all kinds of noise problems. In fact, I have
had just as much noise problems with horizontal dipoles, as I have
with verticals. Much of the local noise here is power line noise.
The lines are horizontal in general, and do emit a horizontaly
polarized
space wave which can travel a fair piece. I've found at this qth,
polarization and noise don't always follow the expected norms.
I've had horizontal antennas that picked up horrible amounts of noise.
But....On the bright side...it does verify that they are working... :/

Here in the cement jungle, I think noise can be about any polarization
depending on the source. Some is vertical, but just as much is also
horizontal. Of course, being vertical can follow a true ground wave
type of propogation, I would expect vertical noise to travel farther
than horizontal if you exceeded the direct line of sight. MK