Attempts to quantify the effects of sea spray evaporation have many uncertainties to contend with. Some, such as the evolution of the temperature and mass of a single droplet for as long as it remains suspended in the atmosphere, are now quite well known. Others, such as the length of time the droplet actually remains suspended, are more difficult. The processes by which droplets are produced are known, but there remain orders of magnitude of variation between estimates of the rate at which these processes operate at various wind speeds. The issue of feedbacks between droplet evaporation and the atmosphere has some important unanswered questions.
A model of evaporating saline droplets within the atmospheric boundary layer was developed, which includes all relevant processes and feedbacks. This has been used to explore a number of the above issues and processes which limit the evaporation of spray are identified and quantified. Existing measurements of sea-air fluxes at high wind speeds are discussed in this context.
New information from the model, physical arguments and recent measurements is used to refine and update our existing bulk parameterisation of the droplet-mediated sea-air flux. Calculations are presented to show the impact of this on tropical cyclone intensification