Observational Study of Black Carbon in Clean Air Area of Western China

Black carbon which has a strong absorption in the visible and infrared range is an important component of aerosols, therefore it contributes significantly to the regional and global effects on aerosols. The observational results of black carbon from July 1994 to December 1995 at Mt. Waliguan Observatory are given. The characteristics of black carbon concentration variation are discussed combined with the meteorological observational data, and then the results were compared with the observational data of black carbon in eastern China. The mean monthly black carbon concentration at Mt. Waliguan varies in the range of 130—300 ng/m3, much lower than that of the eastern China. The variation of black carbon concentration shows an obvious episode pollution transportation under the influence of industrial and dense populated areas, and it varies obviously with the ground wind direction. The background concentrations of black carbon at Mt. Waliguan derived from the mode values of the most frequency statistics, are in the range of 50—120 ng/m3. Both the average concentrations and background concentration are lower in winter and higher in spring.