Understanding the atmospheric chemistry of biomass burning emissions and their impact on air quality and climate

大规模的生物质燃烧事件，包括野火、农业燃烧和住宅燃料燃烧，向大气中释放大量的有机碳。这些排放物会发生化学转化，产生各种各样的二次气体和颗粒物，对气候和空气质量产生重大影响。空气质量和气候变化是我们这个时代最重要的两个环境问题，影响着人类健康、生态系统和经济。世界卫生组织估计，全球每年有880万人直接死于空气污染。暴露于恶劣的空气质量对健康有一系列短期和长期的影响，包括广泛的心血管和呼吸系统疾病，癌症，糖尿病和与痴呆症的联系。在过去十年中，美国，巴西和澳大利亚野火的频率和强度显着增加，由于火灾/土地管理混乱和气候变化，这种趋势可能会继续下去。因此，了解这些排放物中气体和气溶胶相产物的形成变得越来越重要，以便量化其影响并限制其有害影响。在本项目中，我们将设计一系列实验，在约克建造的流动反应器中进行，以研究大气化学，以便了解一系列生物质燃烧排放物的气相和气溶胶相产物的最重要形成途径。这些将侧重于含氧芳香族挥发性有机化合物（VOC），如呋喃和酚类化合物。首先，流动反应器将通过一组在芳族体系上进行的实验来表征，芳族体系的化学机理已经在主化学机理（MCM：mcm.york.ac.uk）中可用。前体物质的损失以及各种气体和气溶胶相产物的形成将使用在线和离线质谱技术（包括PTR-MS）进行测量（质子转移反应质谱法）和SIFT-MS（选择离子流管质谱法）用于气相物质，以及UPLC（超高压液相色谱法）与Orbitrap质谱法耦合用于研究二次有机气溶胶组成。实验将使用基于MCM中可用的详细化学的箱模型进行设计，并针对流动反应器的条件进行优化。新开发和评估的化学机制排放的生物质燃烧化合物将随后纳入MCM。

Large scale biomass burning events, including wildfires, agricultural burn-off and residential fuel combustion, release large quantities of organic carbon to the atmosphere. These emissions can then undergo chemical transformations leading to a wide range of secondary gas and particulate products which can have a significant impact upon climate and air quality.Air quality and climate change are two of the most important environmental issues of our time, impacting human health, ecosystems, and the economy. The World Health Organisation has estimated that globally 8.8 million people die each year as a direct result of exposure to air pollution. Exposure to poor air quality has a range of short and long term impacts on health including a wide range of cardiovascular and respiratory diseases, cancer, diabetes and links to dementia.The frequency and intensity of wildfires in the US, Brazil and Australia have notably increased over the last decade, and this trend is likely to continue owing to fire/land management practises and climate change. Therefore, it is becoming increasingly important to understand the formation of gas and aerosol phase products from these emissions in order to quantify their impacts and limit their detrimental effects.In this project we will design a series of experiments to be carried out in a flow reactor built in York to study atmospheric chemistry, in order to understand the most important formation pathways of gas and aerosol phase products from a range of biomass-burning emissions. These will focus on oxygenated aromatic volatile organic compounds (VOC), such as furans and phenolic compounds. First, the flow reactor will be characterised through a set of experiments carried out on aromatic systems whose chemical mechanisms are already available in the Master Chemical Mechanism (MCM: mcm.york.ac.uk). The loss of the precursor species and the formation of wide range of gas and aerosol phase products will be measured using on and off-line mass spectrometric techniques including PTR-MS (Proton Transfer Reaction mass spectrometry) and SIFT-MS (Selected Ion Flow Tube mass spectrometry) for gas phase species, and UPLC (ultra-high pressure liquid chromatography) coupled to Orbitrap mass spectrometry for investigating secondary organic aerosol composition. Experiments will be designed using box models based around the detailed chemistry available in the MCM, optimised for the conditions of the flow reactor. Newly developed and evaluated chemical mechanisms for emitted biomass burning compounds will subsequently be incorporated into the MCM.