[RightWhale]

how the Water vapor which varies in concentration from place to place and over time in our atmosphere can be creating a relatively uniform magnetic field over the whole planet.

It's not, though. It moves around, it fluctuates in strength, it has totally reversed polarity in the past. That's why I am considering a source for the field that also moves around and varies in constitution from age to age.

[inquest]

So what would cause it to reverse polarity under the water-vapor hypothesis?

By the way, the sun doesn't contain any dipoles, does it?