Sea Spray: Potential Contributions to Global Gas Exchange

Sea spray droplets are an important potential mechanism for transport of gases between the ocean and atmosphere particularly in high wind conditions where their production is enhanced. A model has been developed from the Andreas et al. (1995, 2013) droplet evolution parameterizations to examine the in- or out-gassing of various relatively non-reactive gases (Ar, Ne, He, O₂, N₂) from the droplets. Changes in the size, temperature, and salinity of a droplet according to its evolution and atmospheric residence time drive the movement of gases across this barrier. Conditions within the droplet generally become more hostile to dissolved gases as the droplet evaporates; reducing in volume and increasing in salinity while it remains suspended in the atmosphere. The model can be used to estimate global gas fluxes by applying representative summer and winter values for sea surface temperature, salinity, and air temperature to compare contributions of spray and spume droplets to gas exchange throughout various ocean sub-regions. Wind speeds and wind events across the globe can inform the production of sea spray and potential global impact of gas exchange via sea spray droplets. Under certain conditions, for some gases, the evasion or invasion of gases from sea spray droplets is comparable in magnitude to the interfacial fluxes.