Evolution of phase-space spiral in z − ν_z plane for a solar neighborhood-like region in the disk, at R = 8 kpc. At all times (except the first frame) the bar is rotated by 30° relative to the direction on the galactic center. Top row: stellar density distribution log(ρ(z, ν_z)/max(ρ(z, ν_z))), middle row: mean radial velocity, and bottom row: mean residual azimuthal velocity ν_φ(z, ν_z)−⟨ν_φ(z, ν_z)⟩.