气溶胶光吸收特性是影响气溶胶大气辐射强迫的重要因素,光声光谱技术被认为是测量气溶胶光吸收特性的理想方法之一。利用扫描电迁移率粒径谱仪和自行设计的气溶胶吸收光声光谱仪对合肥郊区大气气溶胶的粒径分布和吸收系数进行了连续测量,获得了某一时段大气气溶胶粒径谱和吸收系数的变化趋势,分析发现大气气溶胶的吸收系数与其数浓度和粒径分布存在较好的正相关性,且碳质气溶胶的排放是影响该地区大气气溶胶光吸收特性的主要原因。
Atmospheric aerosol absorption capacity is a critical parameter determining its direct and indirect effects on climate. Accurate measurement is highly requested for study of the radiative budget of the Earth, photoacoustic spectroscopy is commonly recognized as one of the best candidates to measure the optical absorption coefficient (OAC) of aerosols. A Scanning mobility particle sizer (SMPS) and a homemade photoacoustic aerosol absorptionmeter were used to monitor the size distribution and OAC of the ambient aerosols at suburb of Hefei city, the real-time trends of OAC and size distribution in a serial time were acquired. Properties of the size distribution at different time which was classified into two distribution mode were analyzed in detail. The measured data shows that OAC has a well positive correlation with size distribution and number concentration of the atmospheric aerosol respectively and the emission of carbonaceous aerosol is the chief factor of the effect on OAC.