Representation of the training data sets. The spatial distributions of the vertical velocities (top panels) and Y component of the horizontal velocities (middle panels) of the non-local (left), local (center), and MURaM (right) simulation data. The bottom panels show the probability density functions (left), power spectra of the horizontal velocities (center), and power spectra of the vertical velocities (right) of the three simulations. The vertical and horizontal velocities in the simulations are normalized with zero and unit dispersion. This satisfies Eq. (3).