"However, given that the earth’s magnetic poles are close to its rotational poles, the rotation of the earth does not cause waters to significantly cut through lines of magnetic flux except near the rotational poles. I’d suspect undersea geography as a reason for whirlpools before I’d suspect electromagnetic interaction with ocean waters."
I think assuming ALL of these phenomena to "differences in salinity" or "undersea geography" is problematic. As the article says....ionic conductivity and magnetic fields may also play a part.
One of the interesting tidbits that I picked up while researching "global warming" is that the sun's magnetic field has DOUBLED in strength over the time we have been able to measure it.
Physics says that any conductor moving in a magnetic field generates a current. This MUST mean that the suns field dumps energy into both the molten interior of the earth, AND into the oceans in a mechanism totally "nonphotonic".
How big the effects are.....?????? Despite many years of looking for scientific examination of the effects (or even the existence of same), I have found essentially zip.