Measurements of urban emissions of NOx and VOCs

城市氮氧化物和挥发性有机化合物排放的测量

• 批准号: 2544470
• 金额: --
• 依托单位: University of York
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2544470
• 关键词: Measurements; urban; emissions; NOx; VOCs

This project will, for the first time, link total measured emissions with direct vehicle exhaust emission measurements made within the flux footprint, thus allowing a detailed assessment of the performance of emission inventories and improved inventories to be developed. Emissions are measured via eddy covariance which utilises high time resolution measurements of NO, NO2, speciated VOCs and micrometeorological data from a tall tower site. Eddy covariance has been widely used to assess greenhouse gas budgets in rural/agricultural areas for many years but is more recently being used for air quality pollutants and in urban environments. NOx emissions measurements in London will be made over the period of the PhD at the BT tower in London. In addition, during two intensive filed campaigns in winter and summer 2021, the student will deploy a Selected Ion Flow Tube Mass Spectrometer (SIFT-MS, Voice 200 ultra, Syft Technologies) combined with Automated Gas Calibration Unit (AGCU) to determine the emissions of Benzene, Toluene, Isoprene, ethanol, methanol, C2-alklyl benzenes and C3-alkyl-benzenes using virtually disjunct eddy covariance (v-DEC). Emission will be calculated via classical and continuous wavelet transform eddy covariance techniques, the latter giving improved temporal information about the emissions.Footprint modelling links these local fluxes to the surface allowing them to be compared with emission inventories. The work builds on measurements made from the BT tower in 2017 which showed emission estimates from the NAEI being 20-30% lower than directly measured NOx flux, with the greatest discrepancy being on weekend daytime. The measurements are funded as part of the UKRI / NERC funded Integrated Research Observation System for Clean Air (OSCA) project.

这一项目将首次将测量的总排放量与在通量足迹范围内进行的直接车辆废气排放测量联系起来，从而能够详细评估排放清单的绩效，并改进清单。排放量的测量通过涡度协方差，利用高时间分辨率测量的NO，NO2，挥发性有机化合物和微气象数据从一个高塔网站。涡动协方差已被广泛用于评估农村/农业地区的温室气体预算多年，但最近被用于空气质量污染物和城市环境。在伦敦的氮氧化物排放量测量将在博士期间在英国电信塔在伦敦。此外，在2021年冬季和夏季的两次密集的现场活动中，学生将部署一台选定的离子流管质谱仪（SIFT-MS，Voice 200 Ultra，Syft Technologies）与自动气体校准装置（AGCU）相结合，以确定苯，甲苯，异戊二烯，乙醇，甲醇，C2-烷基苯和C3-烷基苯的排放量使用虚拟分离涡动协方差（v-DEC）。排放量将通过经典和连续小波变换涡度协方差技术计算，后者提供了关于排放量的更好的时间信息，足迹模型将这些当地通量与地表联系起来，使其能够与排放清单进行比较。这项工作建立在2017年英国电信塔的测量基础上，该测量显示NAEI的排放估计比直接测量的NOx通量低20-30%，其中最大的差异是在周末白天。这些测量是由UKRI / NERC资助的清洁空气综合研究观测系统（OSCA）项目的一部分。