Absorption of 632.8 nm Radiation by Maritime Aerosols near Europe

Abstract

The bulk single-scattering albedo of atmospheric particles was determined by simultaneously measuring the optical transmittance and the scattering of light in a multipass cell filled with concentrated ambient aerosol. During a naval research cruise in North Atlantic and the Mediterranean, results were obtained which suggested that the absorption of red light by the maritime aerosol was dominated by particles whose origin was the European continent. Absorption extremes approached 50% of light extinction near industrialized harbor areas. Particle size distributions and albedos measured during the cruise were inverted with Mie theory to give the imaginary part of the particles' refractive index. The mean of the imaginary index for the cruise was 0.0224, which is typical of rural continental areas.