Sea spray induced air-sea heat and salt fluxes based on the wave-steepness-dependent sea spray model

Sea spray, which comprises amounts of small ocean droplets, plays a significant role in the air-sea coupling, atmospheric and oceanic dynamics, and climate. However, it remains arduous to arrive at estimates for the efficiency and accuracy of the sea spray induced air-sea heat and salt fluxes. This is because the microphysical process of sea spray evolution in the air is of extreme complexity. In this study, we iteratively calculated the sea spray induced air-sea heat and salt fluxes at various weather condition. To do so, we implemented one novel wave-steepness-dependent sea spray model into a bulk air-sea fluxes algorithm and utilized other sea spray models as comparisons. Based on the improved wave-dependent bulk turbulent algorithm, we observed that despite the negative contribution of sea spray to the sensible heat fluxes, the sea spray positively contributes to the air-sea latent heat fluxes, leading to an overall increase in the total air-sea heat fluxes. The additional heat fluxes caused by sea spray may be the missing critical process that can clarify the discrepancies observed between measured and modelled Tropical Cyclone's development and intensification. In addition to heat fluxes, we observed that sea spray has significant impacts on the air-sea salt fluxes. As the sea salt particles are one of the main sources of the atmosphere aerosol, our results imply that sea spray could impact global and regional climate. Thus, given the significance of sea spray on the air-sea boundary layer, sea spray effects need to be considered in studies of air-sea interaction, dynamics of atmosphere and ocean.

Automated summary

Sea spray, composed of small ocean droplets, plays a significant role in air-sea coupling, atmospheric and oceanic dynamics, and climate. However, estimating the efficiency and accuracy of sea spray induced air-sea heat and salt fluxes is challenging due to the complexity of the microphysical process. This study implemented a novel wave-steepness-dependent sea spray model and observed that sea spray contributes positively to air-sea latent heat fluxes, leading to an overall increase in total air-sea heat fluxes and significant impacts on air-sea salt fluxes, with potential implications for global and regional climate.