ICOZA: Integrated Chemistry of Ozone in the Atmosphere

ICOZA：大气中臭氧的综合化学

• 批准号: NE/K012029/1
• 负责人: Dwayne Heard
• 金额: $ 17.48万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FK012029%2F1
• 关键词: ICOZA; Integrated; Chemistry; Ozone; Atmosphere

Tropospheric ozone is an important air pollutant, harmful to human health, agricultural crops and vegetation. It is the main precursor to the atmospheric oxidants which initiate the degradation of most reactive gases emitted to the atmosphere, and is an important greenhouse gas in its own right. As a consequence of this central role in atmospheric chemistry and air pollution, the capacity to understand, predict and manage tropospheric ozone levels is a key goal for atmospheric science research. This goal is hard to achieve, as ozone is a secondary pollutant, formed in the atmosphere from the complex oxidation of VOCs in the presence of NOx and sunlight, and the timescale of ozone production is such that a combination of in situ chemical processes, deposition and transport govern ozone levels. Uncertainties in all of these factors affect the accuracy of numerical models used to predict current and future ozone levels, and so hinder development of optimal air quality policies to mitigate ozone exposure. Here, we will address this problem by measuring the local chemical ozone production rate, and (for the first time) perform measurements of the response of the local atmospheric ozone production rate to NOx and VOC levels - directly determining the ozone production regime.We will achieve this aim by building upon an existing instrument for the measurement of atmospheric ozone production rates (funded through a NERC Technology Proof-of-Concept grant, and deployed in the recent ClearfLo "Clean Air for London" NERC Urban Atmospheric Science programme). In addition to directly measuring ozone production, by perturbing the ambient chemical conditions (for example, through addition of NOx or VOCs to the sampled airflow), and measuring the effect of this change upon the measured ozone production rate, the ozone control regime (extent of NOx vs VOC limitation) may be directly determined. Within this project, we will develop our existing ozone production instrument to include this capability, and validate the measurements, through comparison with ozone production from VOC oxidation in a large simulation chamber, and by measurement of the key oxidant OH radicals, and their precursors, within the system.We will then apply the instrument to compare the measured ozone production rates with those calculated using other observational and model approaches, and to characterise the ozone control regime, in two contrasting environments: In the outflow of a European megacity (at Weybourne Atmospheric Observatory, WAO, in the UK), and in a rural continental location (at Hohenpeissenberg, HPB, in southern Germany). At WAO, we will compare the measured ozone production rate with that calculated through co-located measurements of HO2 and RO2 radicals (using a newly developed approach to distinguish between these closely related species), and with that simulated using a constrained photochemical box model. We will compare the NOx-dependence of the ozone production rate with that predicted using indicator approaches, based upon observations of other chemical species. At HPB, we will focus upon the VOC-dependence of the ozone production rate, and assess the error in model predictions of ozone production, which arise from the presence of unmeasured VOCs.The project will develop and demonstrate a new measurement approach, and apply this to improve our understanding of a fundamental aspect of atmospheric chemical processing. Future applications have considerable potential both to support atmospheric science research, but also as an important air quality tool, alongside existing measurement and modelling approaches, to inform the most effective emission controls to reduce ozone production in a given location. In the context of global crop yield reductions arising from ozone exposure of 7 - 12 % (wheat), 6 - 16 % (soybean) and 3 - 4 % (rice), this is an important societal as well as scientific goal.

对流层臭氧是一种重要的空气污染物，对人类健康，农作物和植被有害。它是大气氧化剂的主要前体，它引发了发射到大气的最具反应性气体的降解，并且本身就是重要的温室气体。由于这种核心在大气化学和空气污染中的核心作用，理解，预测和管理对流层臭氧水平的能力是大气科学研究的关键目标。这个目标很难实现，因为臭氧是一种次要污染物，在NOX和Sunlight的存在下，由VOC的复杂氧化形成在大气中，并且臭氧产生的时间表使原位化学过程，地位的结合，地位的结合运输控制臭氧水平。所有这些因素的不确定性都会影响用于预测当前和未来臭氧水平的数值模型的准确性，从而阻碍了最佳空气质量政策的发展，以减轻臭氧暴露。在这里，我们将通过测量本地化学臭氧的生产率来解决这个问题，并（首次）对当地大气臭氧生产率对NOX和VOC水平的响应进行测量 - 直接确定臭氧生产方案。通过建立一种测量大气臭氧生产率的工具来实现这一目标（通过NERC技术概念证明赠款资助，并部署在最近的Clearflo“伦敦清洁空气” NERC城市大气科学计划中）。除了直接测量臭氧产生，通过扰动环境化学条件（例如，通过在采样气流中添加NOX或VOC），并测量这种变化对测得的臭氧生产率的影响，臭氧控制状态（程度范围）可以直接确定NOX与VOC限制）。在该项目中，我们将开发现有的臭氧生产仪器，以包括此能力，并通过与大型模拟室中VOC氧化的臭氧产生以及通过测量关键氧化剂OH激进分子及其前体的前体，以及其前体的前体，以验证测量值。然后，我们将应用该工具将测量的臭氧生产率与使用其他观测和模型方法计算的臭氧生产率进行比较，并在两个对比环境中表征臭氧控制状态：大气天文台，WAO，在英国）和农村大陆位置（在德国南部的HPB的Hohenpeissenberg）。在WAO中，我们将比较测得的臭氧产量与通过共同确定的HO2和RO2自由基的测量（使用新开发的方法来区分这些密切相关的物种），以及使用受约束的光化学盒模型模拟的方法。我们将根据对其他化学物种的观察结果进行比较臭氧生产率的NOX依赖性与使用指标方法的预测。在HPB，我们将重点关注臭氧生产率的VOC依赖性，并评估臭氧产生模型预测的错误，这是由未衡量的VOC的存在引起的。该项目将开发和展示一种新的测量方法，并应用一种新的测量方法这是为了提高我们对大气化学加工的基本方面的理解。未来的应用具有支持大气科学研究的巨大潜力，也是作为重要的空气质量工具，以及现有的测量和建模方法，以告知最有效的排放控制，以减少给定位置中的臭氧产量。在全球作物的背景下，臭氧的暴露量减少了7-12％（小麦），6-16％（大豆）和3-4％（大米），这是一个重要的社会和科学目标。

项目成果

Assessment of interferences during field measurements of OH using a laser-induced fluorescence instrument equipped with a scavenger injector

使用配备清除注射器的激光诱导荧光仪器评估 OH 现场测量过程中的干扰

• 发表时间: 2017
• 作者: Heard, D.E.

Radical chemistry at a UK coastal receptor site - Part 2: experimental radical budgets and ozone production

英国沿海受体点的自由基化学 - 第 2 部分：实验自由基预算和臭氧产生

• DOI: 10.5194/acp-2022-213
• 发表时间: 2022
• 作者: Woodward-Massey R

Implementation of a chemical background method for atmospheric OH measurements by laser-induced fluorescence: characterisation and observations from the UK and China

• DOI: 10.5194/amt-2019-487
• 发表时间: 2020-01
• 期刊: Atmospheric Measurement Techniques
• 影响因子: 3.8
• 作者: Robert Woodward-Massey;Eloise J. Slater;J. Alen;T. Ingham;D. Cryer;L. M. Stimpson;C. Ye;P. Seakins;L. Whalley;D. Heard

Evaluation of Novel Routes for NOx Formation in Remote Regions.

• DOI: 10.1021/acs.est.6b06441
• 发表时间: 2017-06
• 期刊: Environmental science & technology
• 影响因子: 11.4
• 作者: C. Ye;D. Heard;L. Whalley

Radical chemistry and ozone production at a UK coastal receptor site

• DOI: 10.5194/acp-23-14393-2023
• 发表时间: 2023-11
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: Robert Woodward-Massey;R. Sommariva;L. Whalley;D. Cryer;T. Ingham;W. Bloss;S. M. Ball;S. Cox;James D. Lee;C. Reed;L. Crilley;L. Kramer;B. Bandy;G. Forster;C. Reeves;P. Monks;D. Heard