OPTICAL-PROPERTIES OF ATMOSPHERIC AEROSOLS FROM MOMENTS OF THE PARTICLE-SIZE DISTRIBUTION

The method of moments is a powerful tool for directly calculating the lower-order moments of an aerosol size distribution without full knowl edge of the distribution itself. These moments can be tracked in space and time to represent the effects of nucleation, evaporation and grow th, coagulation, and complex flowfield dynamics. This letter applies q uadrature methods for efficient estimation of aerosol optical properti es directly from a known moment sequence. The approach is demonstrated using particle size distributions obtained from fits to field measure ments. Comparison of light-scattering phase functions and other integr al optical properties calculated from the moments with those obtained from the full distributions shows that the lower-order moments lead to an efficient and accurate parametrization for these properties.