On the transfer of momentum, heat and mass at the air-sea and air-sea spray interfaces

This dissertation investigates the macroscopic effects of small-scale processes at the air-sea interface in general, with specific attention to the role that sea spray drops play in the exchanges of momentum, heat and mass between the air and the sea. Through scaling analysis and numerical modeling, this work provides a new understanding of the relative contributions to momentum, heat and mass fluxes at the broadly defined air-sea interface. Succinctly, sea spray drops play a less significant role than previous studies have suggested. This reduced role of sea spray ultimately leads to a lower predicted enthalpy flux at high wind speeds, raising new questions about how hurricanes overcome the drag (or friction) of the surface to become the familiar, swirling disasters. The total air-sea fluxes predicted by the model agree with empirical data at low to moderate wind speeds quite well. The generation function for spume drops predicts more, larger drops, which carry the spray-mediated fluxes at low to moderate wind speeds. At high wind speed conditions, for which data are sparse, this model departs substantially from the extrapolations of previous studies. The generation function shifts to smaller drops with increased wind forcing, and the total mass flux of spume drops saturates. Whereas the larger drops contribute to the spray-mediated fluxes at low wind speeds, the saturation of the mass flux and shift to smaller drops at high winds prevent the spray-mediated fluxes from ever dominating the total air-sea fluxes. Both this model and previous ones provide plausible explanations of the available data, but they each form a very different understanding of hurricane conditions.