Parametric Study Of The Effects Of Sea Spray On Air-Sea Interaction

With the further study of typhoon research, the generation of sea spray and its influence to air-sea interaction at the high wind speed are getting more and more attention by scholars. The existence of sea spray forms a droplet evaporation layer on the sea surface which will change the state of air-sea interface, and impact the moment flux and heat flux exchange between atmosphere and ocean. Further exploration of the sea spray influence will play a prerequisite role in the forecast of typhoon and the design of offshore platform construction.Based on the previous research and observation, the generation mechanism of sea spray is discussed in this paper, and makes a numerical simulation of the sea spray generation with the method of large eddy simulation is included. In the analysis of the data, we find that:the sea spray diffusion around the significant wave height after they are generated, and the distribution of sea spay in the vertical direction is approximately normal distribution; with the increase of wind speed, the number of droplets generated will be gradually increased, but the trend of variation in the vertical direction has not changed.In order to make a better analysis in the factors which influence droplet generation, we summarized the results of previous studies, and made a further improvement on the sea spray generation function based on the data measured by Fairall. With the consideration of wave state, and the sea spray generated by wave break and bubbles burst are all be considered, the new sea spray generation function coverage a larger radius range, the tendency of variation and magnitude are more consistent with the observational data.This paper discussed the influence of droplets on the typhoon. The existence of droplets changed the contact state of the air sea interface. Especially at high wind speed, the droplet number and thickness of mixed layer both reached a certain magnitude, which will change the friction state of the ocean and the atmosphere, so that at high wind speed, drag coefficient will not increase abidingly, but demonstrate a trendy of decline. The presence of droplets enlarge the heat exchange area between air and sea. Which will change the flux of sensible heat and latent heat or the proportion of them at a certain extent and make the character enthalpy transfer coefficient increase persistently. The relative balance of momentum and scalar transfers increase fast with the acceleration of wind speed, which is a necessary condition for the formation of typhoon.