I mean, it does though. The atmosphere is a 3D volume. Parameters that you might be interested in solving for, like advection and convection, are 3D processes.

I mean, it does though. The atmosphere is a 3D volume. Parameters that you might be interested in solving for, like advection and convection, are 3D processes. Consequently, you will need a 3D grid to solve the PDEs describing these parameters. EDIT: Ah, I see what you're saying. Yeah, I believe we fundamentally agree and our posts describe the same reasoning in two different ways.