School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China.
School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Key Lab of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China.
Sci Total Environ. 2018 Jul 1;628-629:631-641. doi: 10.1016/j.scitotenv.2018.02.099. Epub 2018 Feb 20.
In recent years, China has experienced heavy air pollution, especially haze caused by particulate matter (PM). The compositions, horizontal distributions, transport, and chemical formation mechanisms of PM and its precursors have been widely investigated in China based on near-ground measurements. However, the understanding of the distributions and physical and chemical processes of PM in the vertical direction remains limited. In this study, an elastic lidar was employed to investigate the vertical profiles of aerosols along the Yangtze River during the Yangtze River Campaign of winter 2015. Some typical aerosols were identified and some events were analyzed in three cases. Dust aerosols can be transported from the Gobi Desert to the Yangtze River basin across a long distance at both low and high altitudes in early December. The transport route was perpendicular to the ship track, suggesting that the dust aerosols may have affected a large area. Moreover, during transport, some dust was also affected by the areas below its transport route since some anthropogenic pollutants were mixed with the dust and changed some of its optical properties. Biomass-burning aerosols covering a distant range along the Yangtze River were identified. This result directly shows the impact areas of biomass-burning aerosols in some agricultural fields. Some directly emitted aerosol plumes were observed, and direct effects of such plumes were limited both temporally and spatially. In addition, an aerosol plume with very low linear depolarization ratios, probably formed through secondary processes, was also observed. These results can help us better understand aerosols in large spatial scales in China and can be useful to regional haze studies.
近年来，中国经历了严重的空气污染，尤其是由颗粒物（PM）引起的雾霾。基于地面测量，中国已经广泛研究了 PM 及其前体的组成、水平分布、传输和化学形成机制。然而，对 PM 在垂直方向上的分布和物理化学过程的理解仍然有限。在这项研究中，使用弹性激光雷达在 2015 年冬季长江考察期间，对长江沿线气溶胶的垂直剖面进行了探测。在三种情况下，识别了一些典型的气溶胶并分析了一些事件。在 12 月初，沙尘气溶胶可以从戈壁沙漠长距离输送到长江流域，在高低海拔都有输送。输送路径垂直于船舶轨迹，表明沙尘气溶胶可能影响了很大的区域。此外，在输送过程中，一些沙尘也受到其输送路径下方区域的影响，因为一些人为污染物与沙尘混合并改变了其部分光学性质。在长江沿线识别出了远距离生物质燃烧气溶胶。这一结果直接显示了生物质燃烧气溶胶在一些农田中的影响区域。观测到一些直接排放的气溶胶羽流，这种羽流的直接影响在时间和空间上都是有限的。此外，还观测到一个具有非常低线性偏振比的气溶胶羽流，可能是通过二次过程形成的。这些结果可以帮助我们更好地理解中国大空间尺度上的气溶胶，并且对区域雾霾研究也很有用。
