School of Environmental Science and Optoeclectronic Technology, University of Science and Technology of China, Hefei 230026, China; Key laboratory of Environmental Optical and Technology, Anhui Institute of Optics and Fine Mechanies, Chinese Academy of Science, Hefei 230031, China.
School of Environmental Science and Optoeclectronic Technology, University of Science and Technology of China, Hefei 230026, China; Key laboratory of Environmental Optical and Technology, Anhui Institute of Optics and Fine Mechanies, Chinese Academy of Science, Hefei 230031, China; CAS Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
J Environ Sci (China). 2018 Sep;71:207-221. doi: 10.1016/j.jes.2018.03.006. Epub 2018 Mar 15.
Yangtze River Delta (YRD) area is one of the important economic zones in China. However, this area faces increasing environmental problems. In this study, we use ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) network in Eastern China to retrieve variations of NO, SO, and formaldehyde (HCHO) in the YRD area. Three cities of YRD (Hefei, Nanjing, and Shanghai) were selected for long-term observations. This paper presents technical performance and characteristics of instruments, their distribution in YRD, and results of vertical column densities (VCDs) and profiles of NO, SO, and HCHO. Average diurnal variations of tropospheric NO and SO in different seasons over the three stations yielded minimum values at noon or in the early afternoon, whereas tropospheric HCHO reached the maximum during midday hours. Slight reduction of the pollutants in weekends occurred in all the three sites. In general trace gas concentrations gradually reduced from Shanghai to Hefei. Tropospheric VCDs of NO, SO, and HCHO were compared with those from Ozone Monitoring Instrument (OMI) satellite observations, resulting in R of 0.606, 0.5432, and 0.5566, respectively. According to analysis of regional transports of pollutants, pollution process happened in YRD under the north wind with the pollution dissipating in the southeast wind. The feature is significant in exploring transport of tropospheric trace gas pollution in YRD, and provides basis for satellite and model validation.
长江三角洲（YRD）地区是中国重要的经济区之一。然而，该地区面临着日益严重的环境问题。本研究利用中国东部的地基多轴差分光学吸收光谱（MAX-DOAS）网络，反演了 YRD 地区的 NO、SO 和甲醛（HCHO）的变化。选择了 YRD 的三个城市（合肥、南京和上海）进行长期观测。本文介绍了仪器的技术性能和特点、它们在 YRD 的分布以及 NO、SO 和 HCHO 的垂直柱密度（VCD）和廓线结果。三个站点不同季节的对流层 NO 和 SO 的日变化特征表明，它们的最低值出现在中午或午后，而对流层 HCHO 在中午达到最大值。所有三个站点在周末的污染物都略有减少。总的来说，痕量气体浓度从上海到合肥逐渐降低。与 Ozone Monitoring Instrument（OMI）卫星观测的对流层 VCD 相比，NO、SO 和 HCHO 的 R 值分别为 0.606、0.5432 和 0.5566。根据污染物的区域传输分析，在北风条件下，YRD 地区发生了污染过程，污染在东南风条件下消散。这一特征对于探索 YRD 地区对流层痕量气体污染的传输具有重要意义，为卫星和模型验证提供了依据。
