The evaporation of water from sea-spray is thought to modify the exchange of heat and moisture between the ocean and atmosphere. At low wind speeds the effect is negligible, but at high wind speeds (>15 m/s), significant volumes of spray are generated, and the impact on heat and moisture fluxes is believed to be significant. Most of the work on this effect has relied upon theoretical arguments or modelling studies, and evidence from discrepancies between existing bulk flux algorithms and observations under high winds. This study is a collaboration with colleagues at the Rosenstiel School of Marine & Atmospheric Science at the University of Miami, and part of a much larger programme aimed at improving the forecasting of Pacific Typhoons: ITOP (Impact of Typhoons on the Ocean in the Pacific). We will make direct measurements of air-sea fluxes, and the sea-spray aerosol spectra within Typhoons in the East/South China Seas, in order to make direct estimates of the impact of spray production on the air-sea fluxes.