Vorticity storage in Staggered discretization 3D
 

Where is vorticity stored when I discretize the simulation domain using a staggered grid?
Most sources mention cell centres in 2D but strangely I cannot find the same for 3D.
Instuitively, it should not be in the cell centres (where the scalars go and vorticity if like a scalar in 2D).

To be honest, I never worked using the 3D vorticity formulation. As first idea I would think to write the generic component zi to understand the staggered velocity components required to the definition on a cube.