An Junlin, Cao Qimin, Zou Jianan, Wang Honglei, Duan Qing, Shi Yuanzhe, Chen Chen, Wang Junxiu
Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), Joint International Research Laboratory of Climate and Environment Change (ILCEC), Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing, 210044, China.
Key Laboratory of Arid Climatic Changes and Disaster Reduction of Gansu Province, School of Atmospheric Sciences, Lanzhou University, Lanzhou, 730000, China.
Arch Environ Contam Toxicol. 2018 Jan;74(1):1-15. doi: 10.1007/s00244-017-0447-0. Epub 2017 Sep 9.
To investigate the seasonal variation and characterization of water-soluble ions (WSIs) present in airborne particle deposition (APD) during Haze Days (visibility ≤7.5 km) and Normal Days (visibility >7.5 km) in suburban Nanjing area, 151 filter samples were collected from 18 May 2013 to 26 May 2014. Ten different WSIs from the samples were determined by Ion Chromatography. The results indicated that secondary WSIs (NH, NO, and SO) were the main ions in the WSIs, averaging 17.2, 18.5, and 17.1 μg/m, respectively, and accounting respectively 20.9, 22.5, and 20.8% of the total WSIs. On Haze Days, the concentration of WSIs increased dramatically in fine size (particle size <2.1 μm), especially for NH, NO, and SO (increased by 52.6, 71.3, and 73.1%, respectively), whereas the concentrations of WSIs increased slowly in coarse size (2.1 μm < particle size < 10 μm), in which NH, NO, and SO increased by 14.7, 27.2, and 54.5%, respectively. According to the backward trajectories and the principal component analysis analysis, Nanjing APD were mainly derived from the soil dust in northern China (35%) in the spring, from ocean air masses (61 and 55%) in the summer and the autumn, and from local air masses (73%) in the winter. On summer Haze Days, secondary components in PM consisted mainly of (NH)SO and NHNO, whereas secondary components in PM consisted mainly of (NH)SO, NHCl, and NHNO. The increasing concentrations of secondary components increase the light extinction coefficients of aerosol on winter and autumn Haze Days. The concentrations of WSIs in fine size rose sharply on Haze Days, leading the visibility to exponential decline. Differently, the concentrations of WSIs in coarse size were not the main cause in the change of the visibility.
为研究南京郊区雾霾天（能见度≤7.5千米）和正常天（能见度>7.5千米）期间大气颗粒物沉降（APD）中水溶性离子（WSIs）的季节变化及特征，于2013年5月18日至2014年5月26日采集了151个滤膜样品。通过离子色谱法测定了样品中的十种不同水溶性离子。结果表明，二次水溶性离子（NH₄⁺、NO₃⁻和SO₄²⁻）是水溶性离子中的主要离子，平均浓度分别为17.2、18.5和17.1μg/m³，分别占总水溶性离子的20.9%、22.5%和20.8%。在雾霾天，细粒径（粒径<2.1μm）的水溶性离子浓度急剧增加，尤其是NH₄⁺、NO₃⁻和SO₄²⁻（分别增加了52.6%、71.3%和73.1%），而粗粒径（2.1μm<粒径<10μm）的水溶性离子浓度增加缓慢，其中NH₄⁺、NO₃⁻和SO₄²⁻分别增加了14.7%、27.2%和54.5%。根据后向轨迹和主成分分析，南京的大气颗粒物沉降在春季主要来源于中国北方的土壤尘（35%），夏季和秋季主要来源于海洋气团（61%和55%），冬季主要来源于本地气团（73%）。在夏季雾霾天，PM中的二次成分主要为(NH₄)₂SO₄和NH₄NO₃，而在冬季雾霾天，PM中的二次成分主要为(NH₄)₂SO₄、NH₄Cl和NH₄NO₃。二次成分浓度的增加导致秋冬雾霾天气溶胶消光系数增大。雾霾天细粒径水溶性离子浓度急剧上升，导致能见度呈指数下降。不同的是，粗粒径水溶性离子浓度不是能见度变化的主要原因。
