沙尘和黑碳气溶胶的非球形单颗粒形貌模拟及其光学特性研究

在目前的气溶胶辐射强迫计算中，通常采用球形假设并利用Mie理论计算气溶胶颗粒的光学特性，但众多研究发现该假定条件成为计算气溶胶光学特性的主要错误来源。大气气溶胶颗粒通常是非球形的，特别是沙尘颗粒和黑碳聚合体。随着近几年非球形颗粒测量技术的发展和散射计算方法（如T-matrix方法和离散偶极子DDA方法）的不断改进，计算不对称非球形气溶胶颗粒的光学特性成为可能。本申请项目拟通过对沙尘和黑碳气溶胶的单颗粒分析测量数据，结合申请人创新开发的8-5-2沙尘形貌模型和DLSOA黑碳形貌模型，以及气溶胶单组分复合折射系数集DACRI, 计算非球形沙尘和黑碳气溶胶的光学散射系数数据库,初步探讨颗粒形貌差异、聚合状态和颗粒混合模式对气溶胶光学特性的影响,为区域气候模型和非球形气溶胶遥感反演提供重要基础数据。

Nowadays, in the calculation of aerosol radiative forcing, the hypothesis of individual particle as sphere and Mie theory are used to calculate the optical properties of aerosol particles, but many studies have found that the spherical assumption becomes the main source of errors in calculation of aerosol optical properties. Atmospheric aerosol particles always show non-spherical morphologies, specially the dust particles and black carbon aggregates. As in recent years, measurement technology of non-spherical particles and scattering calculation methods (such as the T-matrix method and the discrete dipole DDA) has been continually improved; this provides the possibility to calculate the optical properties of asymmetric non-spherical aerosol particles. This applied project will adopt the actual measuring data from individual particle analysis of dust particles and black carbon aggregates, combined with the 8-5-2 dust morphological model which innovative developed by the applicant and the DLSOA morphological model of black carbon which developed in collaboration with others, as well as the database of aerosol components complex refractive indices(DACRI), to establish a database of non-spherical dust and soot aerosol optical scattering coefficient. Then, we will discuss the effects from morphological differences, aggregated states and particle mixed methods to aerosol optical properties. This research will provide very important basic data for regional climate models and new inversed algorithm of aerosol remote sensing.