Dust particles frequently become mixtures of mineral dust and sea salt during their transport in the marine boundary layer, consequently growing in size and thus making the settling process there fundamentally different from that in the continental atmosphere. We investigated the effect of sea salt on the gravitational settling of dust particles. Results show that the adhering of sea salt to dust particles could dramatically enhance their settling velocity, in particular if the particles becomes larger than 3 or 4 μm. Estimates with data of six dust events observed in southwestern Japan revealed that, due to sea salt, dry deposition fluxes of mineral dust increased approximately 14 ～ 17% in well-mixed events and 4 ～ 6% in less-mixed events, indicating the substantial effect of sea salt on dust settling and the importance of considering this effect in the schemes of particle gravitational settling when mapping dust fluxes to the ocean.
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