Abstract The aerosols accumulating in the surface layer are an important factor in the study of urban environment pollution. In this study, the characteristics and sources of the aerosols within the nocturnal residual layer were investigated based on lidar measurements from May 2015 to July 2016. The results revealed that the annual average aerosol optical depths (AODs) in the residual layer (RL) and the stable boundary layer (SBL) were 0.2 ± 0.16 and 0.17 ± 0.11, respectively. The aerosol loading in the RL was higher than that in the SBL, accounting for 43% of the total surface aerosols. The AOD in the RL during the summer was the highest (0.32 ± 0.14), followed by autumn (0.24 ± 0.16) and spring (0.2 ± 0.16), and was the lowest in winter (0.11 ± 0.07). Moreover, the effects of different layer heights and meteorological parameters at different heights were investigated. The AOD in the RL was positively correlated with the residual layer height (RLH) and residual layer depth (RLD), with a correlation coefficient (R2) of approximately 0.58 and 0.58, respectively. The correlation coefficient between AOD in the RL and relative humidity at the heights of 0.4, 0.7, 1, and 1.3 km was 0.52, 0.52, 0.49, and 0.53, respectively. These results indicated that RLD and humidity would promote aerosol loading in the RL. The air mass potential source contribution function maps s revealed that the aerosols in the RL during spring and autumn originate from local and nearby areas, while the air masses during summer come from the local anthropogenic emission regions. In winter, the air masses that reach Wuhan often originate from the northwestern dust source region via long-distance advection. These findings are significant in the quest to improve our understanding of the effects of aerosols on environmental pollution.

中文翻译：

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武汉夜间残留层气溶胶特征及来源

摘要 表层气溶胶的积累是城市环境污染研究中的一个重要因素。本研究基于 2015 年 5 月至 2016 年 7 月的激光雷达测量研究了夜间残留层内气溶胶的特征和来源。结果表明，残留层 (RL) 中的年平均气溶胶光学深度 (AODs) 和稳定边界层 (SBL) 分别为 0.2 ± 0.16 和 0.17 ± 0.11。RL 中的气溶胶载量高于 SBL，占总表面气溶胶的 43%。RL 夏季 AOD 最高（0.32±0.14），其次是秋季（0.24±0.16）和春季（0.2±0.16），冬季最低（0.11±0.07）。而且，研究了不同层高和不同高度气象参数的影响。RL 中的 AOD 与残留层高度 (RLH) 和残留层深度 (RLD) 呈正相关，相关系数 (R2) 分别约为 0.58 和 0.58。RL 中的 AOD 与 0.4、0.7、1 和 1.3 km 高度的相对湿度之间的相关系数分别为 0.52、0.52、0.49 和 0.53。这些结果表明 RLD 和湿度会促进 RL 中的气溶胶负载。气团潜在源贡献函数图 s 显示，春季和秋季 RL 中的气溶胶来自当地和附近地区，而夏季的气团来自当地的人为排放区。在冬季，到达武汉的气团，往往来自西北沙尘源区，长距离平流。这些发现对于提高我们对气溶胶对环境污染影响的理解具有重要意义。