Light Absorption Properties of Aerosol Particles in Arid Area of Hexi Corridor

The aerosol absorption coefficient(σap) was measured with an aethalometer at Zhangye observatory from March to June in 2008,in combining with the mass concentration of PM10 and the routine weather observation data,and a comprehensive analysis was conducted.We analyzed the general and diurnal variation features of σap.Also we discussed absorptive aerosol transported by local wind and the variation feature of σap during a dust event.It is found that aerosol absorption coefficient at 532 nm had a mean value of 11.9 Mm-1,with standard deviation of 10.1 Mm-1.The diurnal variation of σap was significant,with two peaks at morning(08:00) and at night(21:00),and σap was higher in the night than in the daytime.The diurnal variation of wind direction was one of the main impact factors causing diurnal variation of σap.The dust aerosol also absorbed light,and its mass absorption efficiency was estimated to be 0.016 m2·g-1.