Abstract：Temporal trend of visibility and factors affecting it in the background area of Yangtze River Delta (YRD) were studied based on in-situ observation at Lin'an regional atmospheric background station from 2008 to 2015. A new extraction method was developed in order to obtain the regional background visibility in YRD and assess the impact of human activities on it. The results revealed that the diurnal variation of visibility presented a single peak at Lin'an station, with the lowest value observed at dawn and the highest in the afternoon, respectively; besides, the diurnal variation of visibility showed a negative correlation with that of relative humidity. The seasonal variation of visibility appeared to be mainly influenced by atmospheric pollution, which presented higher value in spring and summer, and lower value in autumn and winter. In addition, from 2008 to 2015, the annual growth rate of visibility had a significant increase in spring and summer while maintained at a stable level in autumn and winter. The statistical analysis showed that high relative humidity and severe air pollution were two important factors for low visibility at Lin'an station. The new extraction method was established based on the observations of both air pollutants and meteorological conditions. The daily average regional background visibility in YRD was 9.7 ±2.2km, which appeared to be affected significantly by anthropogenic emissions, and decreased by 4.4km compared to the regional natural visibility.
浦静姣, 徐宏辉, 马千里. 长江三角洲背景地区大气污染对能见度的影响[J]. 中国环境科学, 2017, 37(12): 4435-4441.
PU Jing-jiao, XU Hong-hui, MA Qian-li. Impacts of atmospheric pollution on visibility in the background area of Yangtze River Delta, China. CHINA ENVIRONMENTAL SCIENCECE, 2017, 37(12): 4435-4441.
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