Environment Research Institute, Shandong University, Jinan 250100, China.
Environment Research Institute, Shandong University, Jinan 250100, China; School of Environmental Science and Engineering, Shandong University, Jinan 250100, China; Jiangsu Collaborative Innovation Center for Climate Change, China.
Sci Total Environ. 2017 Jan 1;575:458-466. doi: 10.1016/j.scitotenv.2016.09.173. Epub 2016 Oct 18.
Daytime and night-time PM and PM samples were simultaneously collected at the summit of Mount Tai during summer and autumn 2014. The mass concentrations and chemical compositions were analysed to determine the temporal variations of PM and PM and their contributions to visibility impairment. In summer, the average mass concentrations of PM and PM were 38.16μg/m and 53.33μg/m, respectively. In autumn, the values were 42.75μg/m and 59.16μg/m. Water-soluble inorganic ions were the most abundant species in both PM and PM, followed by organic mass (OM). Among the major water-soluble ions, SO and NH had higher concentrations in summer than in autumn, whereas the concentration of NO showed the opposite seasonal trend. Lower concentrations of organic carbon (OC), elemental carbon (EC) and water-soluble organic carbon (WSOC) were obtained in summer than in autumn. The water-soluble components (SO, NO, NH and WSOC) showed a clear diurnal variation due to the specific meteorological conditions of Mount Tai. The water content in PM and PM was enhanced by the water-soluble components, especially NHNO. The decreased visibility resulted from the combined influence of particulate matter and relative humidity (RH). The threshold PM concentration corresponding to a visibility of <10km was 56.60μg/m, which decreased with an increase in RH. A revised IMPROVE equation was applied to estimate the light-extinction coefficient b, which was found to be lower for these chemicals in autumn (364Mm) than in summer (482Mm). (NH)SO made the largest contribution to b in both summer and autumn, with an average rate of 56.97%. OM (17.32%) and NHNO (15.13%) were also important contributors, with similar contribution rates. The contribution of NHNO to b was higher during summer, and OM contributions were higher during autumn.
2014 年夏、秋两季，在泰山山顶同时采集了白天和夜间的 PM 和 PM 样本。分析了质量浓度和化学成分，以确定 PM 和 PM 的时间变化及其对能见度损害的贡献。夏季，PM 和 PM 的平均质量浓度分别为 38.16μg/m 和 53.33μg/m。秋季，这两个数值分别为 42.75μg/m 和 59.16μg/m。水溶性无机离子是 PM 和 PM 中最丰富的物质，其次是有机物质（OM）。在主要的水溶性离子中，夏季 SO 和 NH 的浓度高于秋季，而 NO 的浓度则呈现相反的季节趋势。夏季 OC、EC 和 WSOC 的浓度较低。由于泰山特定的气象条件，水溶性成分（SO、NO、NH 和 WSOC）表现出明显的日变化。PM 和 PM 中的水分含量因水溶性成分（尤其是 NHNO）而增加。能见度下降是由于颗粒物和相对湿度（RH）的共同影响。能见度<10km 对应的 PM 浓度阈值为 56.60μg/m，随着 RH 的增加而降低。应用改进的 IMPROVE 方程估算光衰减系数 b，发现秋季（364Mm）这些化学物质的 b 值低于夏季（482Mm）。（NH）SO 对 b 的贡献最大，在夏、秋两季的平均贡献率均为 56.97%。OM（17.32%）和 NHNO（15.13%）也是重要的贡献者，贡献率相似。NHNO 对 b 的贡献在夏季较高，而 OM 的贡献在秋季较高。
