Emission factors of long-lived volatile organic compounds from the 2019–2020 Australian wildfires during the COALA campaign
Emission factors of long-lived volatile organic compounds from the 2019–2020 Australian wildfires during the COALA campaign
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DOI：
10.5194/acp-2021-742
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Asher P. Mouat;C. Paton‐Walsh;J. B. Simmons;Jhonathan Ramirez-Gamboa;D. Griffith;J. Kaiser
中科院分区：
文献类型：
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作者：
Asher P. Mouat;C. Paton‐Walsh;J. B. Simmons;Jhonathan Ramirez-Gamboa;D. Griffith;J. Kaiser
抽象的。在2019/2020年，澳大利亚经历了有史以来最大的野火季节。烟雾覆盖了东南海岸数百平方公里的地区，并到达了新南威尔士州的2020年COALA（澳大利亚上空有机物和气溶胶负载特征）现场活动。使用质子转移反应飞行时间质谱仪（PTR-ToF-MS）夜间观测的子集，我们计算了21种挥发性有机化合物（VOCs）的排放比（ER）和因子（EF）。我们将分析限制在具有足够高寿命的VOC，以便在烟雾排放和到达现场之间的约8小时内受到氧化的影响最小。我们使用氧化VOC与VOC的比率来评估自由基氧化的总量：马来酸酐/呋喃评估OH氧化，（顺式-2-丁烯二醇+呋喃酮）/呋喃评估NO3氧化。我们比较ER计算的羽流的最新鲜的部分，ER计算使用整个夜间。找到两者之间的良好协议，我们能够扩展我们的分析，以挥发性有机化合物测量更多的化学老化部分的羽。我们的分析提供了ER和EF的9种化合物以前没有报告的温带森林在澳大利亚：丙烯醛，戊酮/甲基丁醛，丙酸甲酯，甲基丙烯酸甲酯，丙烯，马来酸酐，苯甲醛，甲基愈创木酚，甲基苯甲酸。我们比较了我们的研究结果与两项研究在类似的澳大利亚生物群系，两项研究集中在美国温带森林。我们发现混合协议的EF从以前的研究澳大利亚野火，并普遍良好的协议与研究集中在美国西部的火灾。这表明，在其他地区的生物质燃烧挥发性有机化合物排放量的综合实地测量可能适用于澳大利亚温带森林。
Abstract. In 2019/2020, Australia experienced its largest wildfire season on record. Smoke covered hundreds of square kilometers across the southeastern coast and reached the site of the 2020 COALA (Characterizing Organics and Aerosol Loading over Australia) field campaign in New South Wales. Using a subset of nighttime observations made by a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), we calculate emission ratios (ERs) and factors (EFs) for 21 volatile organic compounds (VOCs). We restrict our analysis to VOCs with sufficiently high lifetimes to be minimally impacted by oxidation over the ~8 h between when the smoke was emitted and when it arrived at the field site. We use oxidized VOC to VOC ratios to assess the total amount of radical oxidation: maleic anhydride/furan to assess OH oxidation, and (cis-2-butenediol + furanone)/furan to assess NO3 oxidation. We compare ERs calculated from the freshest portion of the plume to ERs calculated using the entire nighttime period. Finding good agreement between the two, we are able to extend our analysis to VOCs measured in more chemically aged portions of the plume. Our analysis provides ERs and EFs for 9 compounds not previously reported for temperate forests in Australia: acrolein, pentanones/methylbutanal, methyl propanoate, methyl methacrylate, propene, maleic anhydride, benzaldehyde, methyl guaiacol, and methylbenzoic acid. We compare our results with two studies in similar Australian biomes, and two studies focused on US temperate forests. We find mixed agreement for EFs presented from previous studies of Australian wildfires, and generally good agreement with studies focused on fires in the Western US. This suggests that comprehensive field measurements of biomass burning VOC emissions in other regions may be applicable to Australian temperate forests.