On Earth the circulation of the atmosphere is driven by evaporation of water from the surface of the oceans, but unless you look at the land, you can't always see the "bands". On Jupiter the circulation of the atmosphere is VISIBLE and so are the bands, even if the actual mechanism (fusion?, fission?, chemical?, geological?) driving it is still being argued about. I wasn't positing a mechanism for the variations in water content. I was stating that taking one set of measurements and assuming that they applied to an entire planet the size of Jupiter is full on 100% stoopid!