Phase Function of Relatively Large Size of Non-spherical Aerosols Originated from the Ocean Estimated from Ray Tracing and Experiments

Abstract

Phase function of relatively large non-spherical aerosol particles containing bubbles is discussed. Aerosol particles distributed around just above the ocean are likely to contain bubbles and are likely to have a relatively large particles size and a non-spherical shape. The phase function of such aerosol particles is no longer followed as the well known phase function derived from Mie scattering theory. A comparison between phase functions of the aerosol particles with and without bubbles is made by using Ray tracing. Laboratory based experiments were conducted with salted water with the different water temperature and wind speed. Phase function was measured with the spectrometer. Although aerosol sampling is difficult to conduct, it is confirmed that forward scattering component is increased in accordance with the increasing of the water temperature. This implies that the size of the aerosol particles just above the water surface is increased with the increasing of the water temperature. Moreover, it is found that the shape of the aerosol particles is no longer sphere in the experimental conditions. Also the aerosol particles contain air bubbles due to the fact that the measured phase functions are matched to those from the ray tracing study.