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Sea salt aerosol (SSA) particles are natural aerosols which exert a large impact on various geo-chemical and geophysical processes and on Earth's climate. Emissions of SSA are mainly influenced by the wind near ocean surface. By so far, most models do not consider SSA with dry radius r(d)>10m. For example, the cutoff size of coarse SSA's r(d) in the Community Earth System Model is about 10m. However, laboratory experiments have provided the evidence that numerous large droplets are not accounted for in theoretical estimations of sea spray generation, especially in high-wind conditions, which consequently affect the large SSA emissions. This study assesses the impact of large SSA on aerosol optical depth (AOD) and aerosol burden in the atmosphere by using Community Earth System Model but with a new parameterization of large SSA emissions in high-wind conditions. Our simulations show that considering the large SSA in the model, the simulated AOD over midlatitude and high-latitude oceans are more consistent with the observation from both Moderate Resolution Imaging Spectroradiometer and Aerosol Robotic Network. And we also found that despite dry deposition, large SSA with r(d)>10m can contribute more than 15% to the total AOD over midlatitude and high-latitude oceans, particularly over oceans between 40 and 65 degrees S, and about 28.5% to the total global SSA mass burden.

Plain Language Summary One large size sea salt aerosol mode is introduced in model emission to supplement the high-wind conditions. Aerosol optical depth and burden of sea salt aerosol with the large size mode are studied in Community Earth System Model. Simulated aerosol optical depth with the large size mode improve the agreements with observations, especially in high-wind regions.