Title: Modeling sea‐salt aerosols in the atmosphere: 2. Atmospheric concentrations and fluxes
Abstract: Atmospheric sea‐salt aerosol concentrations are studied using both long‐term observations and model simulations of Na + at seven stations around the globe. Good agreement is achieved between observations and model predictions in the northern hemisphere. A stronger seasonal variation occurs in the high‐latitude North Atlantic than in regions close to the equator and in high‐latitude southern hemisphere. Generally, concentrations are higher for both boreal and austral winters. With the model, the production flux and removal flux at the atmosphere‐ocean interface was calculated and used to estimate the global sea‐salt budget. The flux also shows seasonal variation similar to that of sea‐salt concentration. Depending on the geographic location, the model predicts that dry deposition accounts for 60–70% of the total sea‐salt removed from the atmosphere while in‐cloud and below‐cloud precipitation scavenging accounts for about 1% and 28–39% of the remainder, respectively. The total amount of sea‐salt aerosols emitted from the world oceans to the atmosphere is estimated to be in the vicinity of 1.17×10 16 g yr −1 . Approximately 99% of the sea‐salt aerosol mass generated by wind falls back to the sea with about 1–2% remaining in the atmosphere to be exported from the original grid square (300×300 km). Only a small portion of that exported (∼4%) is associated with submicron particles that are likely to undergo long‐range transport.