Aerosol scattering properties in northern China

The aerosol scattering properties were investigated at two continental sites in northern China in 2004. Aerosol light scattering coefficient (σsp) at 525 nm, PM10, and aerosol mass scattering efficiencies (α) at Dunhuang had a mean value of 165.1±148.8 M m−1, 157.6±270.0 μg m−3, and 2.30±3.41 m2 g−1, respectively, while these values at Dongsheng were, respectively, 180.2±151.9 M m−1, 119.0±112.9 μg m−3, and 1.87±1.41 m2 g−1. There existed a seasonal variability of aerosol scattering properties. In spring, at Dunhuang PM10, σsp, and α were 184.1±211.548 μg m−3, 126.3±89.6 M m−1, and 1.05±0.97 m2 g−1, respectively, and these values at Dongsheng were 146.4±142.1 μg m−3, 183.4±81.7 M m−1, and 1.98±1.52 m2 g−1, respectively. However, in winter at Dunhuang PM10, σsp, and α were 158.1±261.4 μg m−3, 303.3±165.2 M m−1, and 3.17±1.93 m2 g−1, respectively, and these values at Dongsheng were 155.7±170.1 μg m−3, 304.4±158.1 M m−1, and 2.90±1.72 m2 g−1, respectively. σsp and α in winter were higher than that in spring at both the sites, which coincides with the characteristics of dust aerosol and pollution aerosol. Overall, the dominant aerosol types in spring and winter at both sites in northern China are dust aerosol and pollution aerosol, respectively.