Estimation of atmospheric sea salt dry deposition: Wind speed and particle size dependence

Abstract

Cascade impactor and bulk filter samples of atmospheric sea salt were collected at wind speeds from 3.4 to 10 m/s at coastal tower sites in the Florida Keys and Enewetak Atoll as part of the SEAREX (Sea Air Exchange) Program. Simultaneous dry deposition measurements were made to polyethylene plates. The samples were analyzed for Na as an indicator of sea salt. If the observed atmospheric sea salt particle mass distributions are corrected for the reduced collection efficiency of large particles, the observed dry deposition rates agree well with rates estimated from atmospheric sea salt particle concentrations and theoretical particle deposition velocities derived from gravitational settling velocities or from the equations of Slinn and Slinn (1980, 1981) for deposition to smooth, solid surfaces as well as natural water surfaces. The results emphasize the fact that even though large particles may represent only a small fraction of the total mass of sea salt over the ocean, they can dominate the dry deposition rates of the sea salt aerosol.

Modeling of sea salt in a regional climate model: Fluxes and radiative forcing

“…As a result, over the ATL domain, dry deposition is maximum in DJF (Figure 9c), with values of about 80 mg m −2 d −1 , and decreases by over a factor of 4 in JJA. Erickson and Duce [1988] found maximum dry deposition rates over the northern Atlantic of about 200–450 mg m −2 d −1 , while McDonald et al [1982] found dry deposition rates in the range of 40–120 mg m −2 d −1 for wind speeds ranging from 6.5 to 10 m s −1 . This indicates that our results are within the limits of values reported in the literature.…”

Chloride penetration into concrete structures in the marine atmosphere zone – Relationship between deposition of chlorides on the wet candle and chlorides accumulated into concrete

“…When wind speed increases, there is an increase in both the number of marine particles generated and the percentage of larger drops in the aerosol spectrum [17,18]. As a consequence, salt concentrations exponentially increase with wind speed [17,19,20].…”

Relationship between wind speed and aerosol optical depth over remote ocean

“…Definite correlation has been found between surface wind speed and sea salt aerosol concentration (McDonald et al, 1982;O'Dowd and Smith, 1993;Nilsson et al, 2001). The influence of wind speed on marine AOD, τ , in the atmosphere is a much more difficult problem (Platt and Patterson, 1986;Villevalde et al, 1994;Smirnov et al, 1995;Moorthy et al, 1997).…”