A parameterization of sea-salt aerosol source function for sub- and super-micron particles

Abstract

A parameterization of a sea-salt source function for both sub- and super-micron particles was developed based on the semi-empirical formulation of Monahan et al. [1986]. This new parameterization extends the range of Monahan's equation to below 0.2 μm in diameter where it has been found to overestimate submicron sea-salt aerosols, especially the sea-salt number concentrations. The new parameterization was used in a one-dimensional (1-D) column model to predict the number size distributions and compared with reasonable agreement to the observed distributions at various wind speeds reported by O'Dowd et at. [1997]. A global 3-D sea-salt simulation with this parameterization was also made and a much better dependence of sea-salt on surface wind speed was predicted than other schemes compared to observations. For an indirect impact assessment of sea-salt aerosols on climate where submicron particles may have a dominant contribution to aerosol-cloud interactions, this scheme provides the most realistic number flux of sea-salt particles between ocean and atmosphere. Copyright 2003 by the American Geophysical Union.