Street-scale air quality modelling for Beijing during a winter 2016 measurement campaign
Street-scale air quality modelling for Beijing during a winter 2016 measurement campaign
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DOI：
10.5194/acp-2019-783
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发表时间：
2019-09
影响因子：
6.3
通讯作者：
M. Biggart;J. Stocker;R. Doherty;O. Wild;M. Hollaway;Davis Carruthers;Jie Li;Qiang Zhang;
中科院分区：
文献类型：
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作者：
M. Biggart;J. Stocker;R. Doherty;O. Wild;M. Hollaway;Davis Carruthers;Jie Li;Qiang Zhang;
抽象的。我们研究了2016年11月至12月中国特大城市大气污染与人体健康（APHH-中国）冬季测量活动期间北京NOx，NO2，O3和PM2.5浓度的街道尺度变化。使用城市空气污染扩散和化学模型ADMS-Urban和道路源排放的显式网络进行模拟。使用了两个版本的网格化中国多分辨率排放清单（MEIC v1.3）：标准MEIC v1.3排放和优化版本，均为3 km分辨率。我们构建了一个新的交通排放清单分配到一个详细的空间路线图的交通部门。当使用优化的排放清单时，北京空气质量监测网络和大气物理研究所（IAP）现场的平均模拟和测量的污染物浓度之间的协议得到改善。快速NOx-O3化学和明确的交通排放的列入使主要道路附近的尖锐的浓度梯度，以解决与模型。然而，NO2浓度被高估接近道路，可能是由于假设整个研究领域的统一交通活动。测量和模拟的昼夜NO2循环之间的差异表明，一个额外的晚上氮氧化物排放源，可能与重型柴油卡车，是不完全占在排放清单。通过延迟模式中稳定边界层条件的形成来模拟北京的城市热岛效应，从而降低了模拟傍晚NO2的高估。整个监测网络的模拟活动期间平均PM2.5浓度范围（1.15 µg m−3）远低于测量范围（1.40 µg m−3）。这可能是PM2.5排放量和空间变异性不足、忽略明确的点源以及假设背景PM2.5水平均匀的结果。敏感性研究强调，使用明确的道路源排放，修改的昼夜排放曲线，并列入城市热岛效应允许模拟和测量的NO2浓度之间更接近的协议。这项工作为未来复杂城市地区人类暴露于环境空气污染的研究奠定了基础，APH-China活动测量提供了评估关键过程对街道空气质量影响的宝贵手段。
Abstract. We examine the street-scale variation of NOx, NO2, O3 and PM2.5 concentrations in Beijing during the Atmospheric Pollution and Human Health in a Chinese Megacity (APHH-China) winter measurement campaign in November–December 2016. Simulations are performed using the urban air pollution dispersion and chemistry model ADMS-Urban and an explicit network of road source emissions. Two versions of the gridded Multi-resolution Emission Inventory for China (MEIC v1.3) are used: the standard MEIC v1.3 emissions and an optimised version, both at 3 km resolution. We construct a new traffic emissions inventory by apportioning the transport sector onto a detailed spatial road map. Agreement between mean simulated and measured pollutant concentrations from Beijing's air quality monitoring network and the Institute of Atmospheric Physics (IAP) field site is improved when using the optimised emissions inventory. The inclusion of fast NOx–O3 chemistry and explicit traffic emissions enables the sharp concentration gradients adjacent to major roads to be resolved with the model. However, NO2 concentrations are overestimated close to roads, likely due to the assumption of uniform traffic activity across the study domain. Differences between measured and simulated diurnal NO2 cycles suggest that an additional evening NOx emission source, likely related to heavy-duty diesel trucks, is not fully accounted for in the emissions inventory. Overestimates in simulated early evening NO2 are reduced by delaying the formation of stable boundary layer conditions in the model to replicate Beijing's urban heat island. The simulated campaign period mean PM2.5 concentration range across the monitoring network (∼15 µg m−3) is much lower than the measured range (∼40 µg m−3). This is likely a consequence of insufficient PM2.5 emissions and spatial variability, neglect of explicit point sources, and assumption of a homogeneous background PM2.5 level. Sensitivity studies highlight that the use of explicit road source emissions, modified diurnal emission profiles, and inclusion of urban heat island effects permit closer agreement between simulated and measured NO2 concentrations. This work lays the foundations for future studies of human exposure to ambient air pollution across complex urban areas, with the APHH-China campaign measurements providing a valuable means of evaluating the impact of key processes on street-scale air quality.