I know that the earth has atmospheric banding like the gas giants.

What I want to know is why six in specific? What physical processes or equations determine the number of atmospheric bands on a planet with an atmosphere?

Also I'm not sure if the intertropical convergence zone counts as a 'band'. If it does the same question holds for why we have seven bands.


This is a follow up to


And has been reposted due to comment request from here