Abstract：To study the relationship between atmospheric visibility and chemical composition of PM2.5 in Nanjing, samples of PM2.5 were collected and chemical composition were analyzed from 4August to 17August and from 31 October to 11November 2011 in urban Nanjing, while observations of atmospheric visibility, PM2.5, relative humidity, etc. were conducted simultaneously. Investigations showed that atmospheric visibility in Nanjing was higher in summer (~10.9km) than that in autumn (~7.5km) during the sampling period. The correlation coefficient between atmospheric visibility and PM2.5 was -0.75which indicated the low visibility when the concentration of PM2.5 was high. Water-soluble ionic and carbonaceous components accounted for 38% and 26% of PM2.5concentration. The correlation between atmospheric visibility and NO3-、SO42-、NH4+、EC was significant. Particles, occupying 98.2%, was most important for ambient light extinction coefficient. The largest contributor to ambient light extinction in August was (NH4)2SO4(47.0%), OC and NH4NO3accounting for 19.2% and14.3%. (NH4)2SO4, NH4NO3 and OC contributed 28.7%、29.3% and 26.8% to light extinction coefficient in November. The atmospheric visibility were fit with chemical composition of PM2.5in different relative humidity ranges. Using the concentration of PM2.5 chemical composition simulated by WRF/Chem, the atmospheric visibility in August and November of 2011 was calculated with the fitting relationship formulae and the American IMPROVE formula, respectively. In general, the calculated visibility from the fitting relationship formulae was better than the IMPROVE formula comapred to observations.
沈铁迪, 王体健, 陈璞珑, 蒋自强. 南京城区夏秋季能见度与PM2.5化学成分的关系[J]. 中国环境科学, 2015, 35(3): 652-658.
SHEN Tie-Di, WANG Ti-Jian, CHEN Pu-Long, JIANG Zi-Qiang. Relationship between atmospheric visibility and chemical composition of PM2.5 in the summer and autumn of Nanjing. CHINA ENVIRONMENTAL SCIENCECE, 2015, 35(3): 652-658.
