中国地区气溶胶类型特性分析

Characteristics of aerosol types over China

利用全球气溶胶观测网(AERONET)2001年—2012年中国地区12个站点的地基遥感气溶胶物理光学特性产品研究了中国地区气溶胶类型特性及其时空变化规律。研究发现中国地区不同类别的气溶胶光学特性(单次散射反照率、不对称因子、光学厚度等)差异较大,由沙尘型、混合型、强散射型细粒子、弱吸收型细粒子、中度吸收型细粒子和强吸收型细粒子等6类组成。中国地区气溶胶类型具有极强的空间变化特性和明显的季节、年际变化特征,沙尘气溶胶主要出现在春季,强散射型细粒子气溶胶主要出现在夏季,而强吸收型细粒子气溶胶主要出现在秋冬季节;近10年间沙尘型、混合型和强散射型细粒子气溶胶呈现上升趋势,而强吸收型细粒子气溶胶则处于下降趋势。在此基础上对比了中国和美国、法国典型站点气溶胶类型,研究发现3个站点的气溶胶差异较大,中国强吸收细粒子类所占的比重高于后两者,同时强散射细粒子类所占的比重低于后两者。

The characteristics of aerosol types and their temporal-spatial properties are investigated using ground-based observation data at twelve AERONET sites in China. The aerosols are categorized into six types, namely dust, mixture, strong-scattering fine Sized Particles （SS）, slightly absorbing fine Sized Particles （SA）, moderate absorbing fine Sized Particles （MA）, and high absorbing fine Sized Particles （HA）. The optical characteristics （Single Scattering Aldedo （SSA）, Asymmetry Parameter （ASY）, and Aerosol Optical Thickness （AOT） ） of different aerosol types vary greatly. The aerosol types of China show high spatial variation and strong seasonal periodicity. The dust aerosols occur mainly in spring; SS aerosol types are most observed in summer; and HA aerosol types are mostly found in winter. Between 2003 and 2012, the dust, mixture, and SS aerosol types had an increasing trend, while the HA aerosol types showed an opposite tendency. Furthermore, the differences in aerosol types between China, United States, and France were studied. The HA aerosol types were in higher proportion and SS aerosol types were in lower proportion in China than in the United States and France.