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.

该项目将首次将总测量排放量与通量足迹内进行的直接车辆尾气排放测量联系起来，从而可以对排放清单的绩效进行详细评估并改进清单。排放量通过涡流协方差测量，该涡流协方差利用高时间分辨率测量 NO、NO2、特定挥发性有机化合物以及来自高塔站点的微气象数据。涡流协方差多年来一直被广泛用于评估农村/农业地区的温室气体预算，但最近被用于评估空气质量污染物和城市环境。伦敦的氮氧化物排放测量将在博士期间在伦敦英国电信塔进行。此外，在 2021 年冬季和夏季的两次密集实地活动中，学生将部署选择性离子流管质谱仪（SIFT-MS、Voice 200 ultra、Syft Technologies）与自动气体校准装置 (AGCU) 相结合，以确定排放量使用几乎不相干涡度协方差计算苯、甲苯、异戊二烯、乙醇、甲醇、C2-烷基苯和 C3-烷基苯（v-DEC）。排放量将通过经典的连续小波变换涡流协方差技术进行计算，后者提供了有关排放量的改进的时间信息。足迹建模将这些局部通量与表面联系起来，允许它们与排放清单进行比较。这项工作建立在 2017 年 BT 塔测量的基础上，该测量显示 NAEI 的排放估算值比直接测量的氮氧化物通量低 20-30%，其中周末白天的差异最大。这些测量是 UKRI / NERC 资助的清洁空气综合研究观测系统 (OSCA) 项目的一部分。