This is a two-dimensional pseudospectral code written by Pablo Mininni and modified by Santiago J. Benavides to include the out-of-plane velocity, which is coupled to the vertical vorticity with a rotation in the y-direction.

The system of equations being solved is the following:

where omega is the vorticity in the out-of-plane direction, psi is the corresponding streamfunction, and vz is the out-of-plane velocity.