Spray dynamics were examined by means of laser-initiated fluorescence (LIF). These experiments reveal extensive and intermittent dynamic effects. The extent of spray intermittency is a strong function of the water flow rate. The area fraction occupied by the spray correlates (R-2 = 0.81) with the ratio of water momentum input to air momentum input. The area fraction is also strongly affected by secondary air feeds or withdrawals. The measured spray field was compared with the predictions of the PSI-Cell model, a numerical, steady-state model that combines interactive heat, mass, and momentum transfer effects and a k - epsilon representation of turbulence. The model predicts the basic shape of the spray and approximate internal conditions. Turbulent droplet dispersion and vortical structures resulting from the shear at the edge of the jet are likely causes of spray intermittency.