Influence of meteorological conditions and particulate matter on visual range impairment in Jinan, China.

To understand the influence of aerosol particles and meteorological conditions on visual range in Jinan, the capital of Shandong Province, China, PM(2.5) and PM(10) samples were collected from November 2004 to September 2005. The mass concentrations of PM(2.5) and PM(10), concentrations of water-soluble ions in PM(2.5) and concentrations of black carbon (BC) in the atmosphere were analyzed. The decrease of visual range in Jinan results from the combined influence of PM(2.5), PM(10) and meteorological conditions. For the period studied, the average light extinction coefficient, b(ext), which was estimated from an equation developed by the IMPROVE network was 292 Mm(-1). Ammonium sulfate was the major contributor to visual range impairment, accounting for 41%, while ammonium nitrate, particulate organic matter (POM) and BC made comparable contributions accounting for 20%, 22% and 18%, respectively. This highlights the significance of secondary particles ((NH(4))(2)SO(4), NH(4)NO(3), POM) in visual range impairment in Jinan. The data from this study are also compared with the long-term variations of visual range in Jinan from 1961 to 2005.