An estimate of dF0/dr, the sea spray aerosol production per increment droplet radius per unit time per unit area of the ocean, has recently been obtained from a term-by-term evaluation of the following expression: dF0/dr=dE/drT1W(U). The differential whitecap aerosol productivity, dE/dr, the number of aerosol droplets per increment droplet radius produced during the decay of a unity area of whitecap, has been redetermined, for the size range 0.8 μm<r<μm, from the results of recent experiments in the University College, Galway, whitecap simulation tank in which Particle Measuring Systems aerosol spectrometers were used. The characteristic decay time for whitecaps, &tgr;, and the initial whitecap area were in the present study determined from the frame-by-frame analysis of cine-film recordings of whitecaps generated by the simulation tank. The fraction of the sea surface covered by whitecaps W at wind speed U was taken from Monahan and O'Muircheartaigh (1980). The resutling expression, representing the local sea surface aerosol source function in the units of m-2 s-1 μm-1 appropriate for inclusion in any model for the prediction of the vertical profile of aerosols within the marine boundary layer, is given by dF0/dr=5.77¿10-6U3,41(ΔdN/dr), where the last term represents the change in aerosol concentrations per increment droplet radius, expressed in m-3 μm-1, that occurs in the air within the hood over the tank when an individual whitecap decays.