A wave roughness Reynolds number parameterization of the sea spray source flux

Abstract

Parameterizations of the sea spray aerosol source flux are derived as functions of wave roughness Reynolds numbers, RHa and RHw, for particles with radii between 0.176 and 6.61 μm at 80% relative humidity. These source functions account for up to twice the variance in the observations than does wind speed alone. This is the first such direct demonstration of the impact of wave state on the variability of sea spray aerosol production. Global European Centre for Medium-Range Weather Forecasts operational mode fields are used to drive the parameterizations. The source flux from the RH parameterizations varies from approximately 0.1 to 3 (RHa) and 5 (RHw) times that from a wind speed parameterization, derived from the same measurements, where the wave state is substantially underdeveloped or overdeveloped, respectively, compared to the equilibrium wave state at the local wind speed. Key Points Sea spray aerosol source function is derived in terms of a wave Reynolds number The Reynolds number explains more flux variability than wind speed alone Wave state modifies the wind-driven flux by a factor between 0.1 and 3. © 2013. American Geophysical Union. All Rights Reserved.