灰霾天气期间南京气溶胶的化学组成及光学特性研究

摘要

利用2013年6月—12月灰霾天气期间南京城郊气溶胶采样结果，研究气溶胶中水溶性离子的特征和相关性；结合同期城区的大气成分逐时观测资料，分析黑碳的日变化及其与气态污染物的关系；运用光学参量计算模型（OPAC）和辐射传输模型（TUV）研究气溶胶的光学特性及辐射强迫。结果表明：发生灰霾天气时南京城郊主要大气污染物是细颗粒，其中 SO2－4与 NO －3是最主要的水溶性无机盐离子，NO －3／SO2－4质量比较高，呈现硫酸盐和硝酸盐混合型污染特征。黑碳浓度具有明显的日变化特征，呈双峰型结构。灰霾期间硫酸盐气溶胶在大气层顶和地面造成的平均辐射强迫分别为－10．6 W／m2和－10．8 W／m2，黑碳气溶胶在正午大气层顶和地面造成的平均辐射强迫分别为9．12 W／m2和－29．77 W／m2。%This study analyzed the characteristics of water soluble particles sampled during haze events in the suburb of Nanjing from June 201 3 to December 201 3,studied the daily variation of black carbon (BC)and the correlation between BC and gaseous pollutants by using the hourly data collected during the same period and estimated the optical properties and radiative forcing with OPAC (Optical Properties of Aerosols and Clouds)and TUV (Tropospheric Ultraviolet and Visible radiation model).The investigations showed that PM2.5 was the main contributor to haze of suburb in Nanjing.SO2 -4 and NO -3 was the most important inorganic water-soluble ions, and the value of NO -3 /SO2 -4 was high,which indicated a mixed type of pollution.The daily variation of the con-centrations of BC sketched a curve with two peaks.During the haze pollution,sulfate aerosol had an average ra-diative forcing of -1 0.8 W/m2 at the surface and -1 0.6 W/m2 at the top of the atmosphere.BC had an aver-age radiative forcing of -29.77 W/m2 at the surface and 9.1 2 W/m2 at the top of the atmosphere at noon.