Abstract. We present high spatial resolution (up to 2.2 × 2.2 km² simulations focussed over south-west Germany using the online coupled regional atmospheric chemistry model system MECO(n). Numerical simulation of nitrogen dioxide (NO₂) surface volume mixing ratios (VMR) are compared to in situ measurements from a network with 193 locations including background, traffic-adjacent and industrial stations to investigate the model's performance in simulating the spatial and temporal variability of short-lived chemical species. We show that the use of a high-resolution and up-to-date emission inventory is crucial for reproducing the spatial variability, and resulted in good agreement with the measured VMRs at the background and industrial locations with an overall bias of less than 10 %. We introduce a computationally efficient approach that simulates diurnal and daily variability in monthly resolved anthropogenic emissions to resolve the temporal variability of NO₂. MAX-DOAS measurements performed at Mainz (49.99° N, 8.23° E) were used to evaluate the simulated tropospheric vertical column densities (VCD) of NO₂. We propose a consistent and robust approach to evaluate the vertical distribution of NO₂ in the boundary layer by comparing the individual differential slant column densities (dSCDs) at various elevation angles. This approach considers details of the spatial heterogeneity and sensitivity volume of the MAX-DOAS measurements while comparing the measured and simulated dSCDs. The effects of clouds on the agreement between MAX-DOAS measurements and simulations have also been investigated. For low elevation angles ≤ 8°), small biases in the range of −14 to +7 % and Pearson correlation coefficients in the range of 0.5 to 0.8 were achieved for different azimuth directions in the cloud-free cases indicating good model performance in the layers close to the surface. Accounting for diurnal and daily variability in the monthly resolved anthropogenic emissions was found to be crucial for the accurate representation of time series of measured NO₂ VMR and dSCDs and is particularly critical when the atmospheric lifetime of NO₂ is relatively long.

中文翻译：

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使用原位和MAX-DOAS NO ₂测量评估耦合的高分辨率大气化学模型系统MECO（n）

摘要。我们使用在线耦合的区域大气化学模型系统MECO（n），提出了高空间分辨率（最多针对德国西南地区的2.2×2.2 km ²模拟）。二氧化氮（NO ₂）的数值模拟将表面体积混合比（VMR）与来自193个位置的网络（包括背景站，交通邻近站和工业站）的现场测量结果进行比较，以研究该模型在模拟短寿命化学物种的时空变化方面的性能。我们表明，高分辨率和最新的排放清单的使用对于再现空间变异性至关重要，并且与背景和工业位置的测量VMR良好吻合，总体偏差小于10％ 。我们引入了一种计算有效的方法，该方法模拟了每月解析的人为排放量的每日和每日变化，以解决NO ₂的时间变化。。在美因兹（49.99°N，8.23°E）进行的MAX-DOAS测量用于评估NO ₂的模拟对流层垂直柱密度（VCD）。我们提出了一种一致而稳健的方法，通过比较各个差分斜柱密度（dSCD）来评估边界层中NO ₂的垂直分布s）在各种仰角。这种方法在比较测量的和模拟的dSCD时考虑了MAX-DOAS测量的空间异质性和灵敏度的细节。还研究了云对MAX-DOAS测量与模拟之间一致性的影响。对于≤8°的小仰角，在无云情况下，对于不同的方位角方向，可实现-14至+ 7％的小偏差，而皮尔逊相关系数在0.5至0.8的范围内。层靠近表面。发现每月解析的人为排放量的日变化和日变化对于准确表示所测NO ₂ VMR和dSCD的时间序列至关重要s，并且在NO ₂的大气寿命相对较长时特别重要。