After being socked in at Tahiti, I am coming up with a new mechanism for heating the equatorial belt.
First of all, the currents are not driven by the wind. The heat energy ratio is 4000 to one, and the tail can't wag the dog. Simple measurements would prove this. The belt is always cloudy and I kept thinking of mechanisms that could get by this. Now, I don't have to hurt my brain on that.
If the side belts are clear, then there is tremendous solar flux. In Tahiti, as soon as the sun broke through, you had to hide. Unbelievably powerful. This hot water convects to the belt (slight bulge). You can see the high cloud over the cold water in the East Pacific.
ps. and yet, I'm thinking this is not sufficient. We need a non-linear mechanism.