An improved representation of fire non-methane organic gases (NMOGs) in models: emissions to reactivity
An improved representation of fire non-methane organic gases (NMOGs) in models: emissions to reactivity
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DOI：
10.5194/acp-22-12093-2022
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发表时间：
2022-09
影响因子：
6.3
通讯作者：
T. Carter;C. Heald;J. Kroll;E. Apel;D. Blake;M. Coggon;A. Edtbauer;G. Gkatzelis;R. Hornbrook;J. Peischl;E. Pfannerstill;F. Piel;Nina G. Reijrink;A. Ringsdorf;C. Warneke;Jonathan Williams;A. Wisthaler;Lu Xu
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作者：
T. Carter;C. Heald;J. Kroll;E. Apel;D. Blake;M. Coggon;A. Edtbauer;G. Gkatzelis;R. Hornbrook;J. Peischl;E. Pfannerstill;F. Piel;Nina G. Reijrink;A. Ringsdorf;C. Warneke;Jonathan Williams;A. Wisthaler;Lu Xu
摘要。火灾排放大量非甲烷有机气体（NMOGs），其在大气中的氧化会促进臭氧和二次颗粒物的形成。然而，这些火灾排放的NMOGs的丰度和反应性并不确定，且历来没有得到很好的约束。在这项工作中，我们在一个全球化学传输模型（GEOS - Chem）中扩展了火灾排放的NMOGs的表示形式。我们将排放因子更新为安德烈亚（2019年）的数据，并更新化学机制以纳入近期对芳香烃以及乙烯和乙炔模型的改进（贝茨等人，2021年；权等人，2021年）。我们通过在模型中添加集总呋喃（包括其火灾排放和氧化化学过程）以及添加模型中已有的九种物质的火灾排放来扩展NMOGs的表示形式，利用火灾对区域到全球环境影响（FIREX）实验室研究的数据，根据反应性对它们进行优先排序。基于量化的排放因子，我们估计我们改进后的表示形式涵盖了热带稀树草原和温带森林火灾排放的已确定的NMOG碳质量的72%以及羟基（OH）反应性的49%，相较于标准模型有了大幅提高（标准模型涵盖质量的49%，OH反应性的28%）。我们利用巴西亚马逊高塔观测站（ATTO）、美国的火灾对区域到全球环境和空气质量的影响（FIREX - AQ）以及对流层云与辐射实验（DC3）以及加拿大北部的飞机和卫星对对流层成分的北极研究（ARCTAS）的观测数据对我们模型中的火灾排放的NMOGs进行评估。我们表明，包括呋喃在内的NMOGs在美国东部得到了很好的模拟，但在美国西部存在一些低估情况，并且添加火灾排放提高了我们在加拿大北部模拟乙烯的能力。我们估计，火灾在全球范围内提供了年均模拟地表OH反应性的15%，在火源区域这一比例超过75%。在大陆区域，大约一半的模拟火灾反应性来自NMOG物质。我们发现呋喃和乙烯在全球反应性方面很重要，而苯酚在北方地区的局部层面更为重要。这是首次对火灾对大气反应性影响的全球评估。
Abstract. Fires emit a substantial amount of non-methane organic gases (NMOGs), the atmospheric oxidation of which can contribute to ozone and secondary particulate matter formation. However, the abundance and reactivity of these fire NMOGs are uncertain and historically not well constrained. In this work, we expand the representation of fire NMOGs in a global chemical transport model, GEOS-Chem. We update emission factors to Andreae (2019) and the chemical mechanism to include recent aromatic and ethene and ethyne model improvements (Bates et al., 2021; Kwon et al., 2021). We expand the representation of NMOGs by adding lumped furans to the model (including their fire emission and oxidation chemistry) and by adding fire emissions of nine species already included in the model, prioritized for their reactivity using data from the Fire Influence on Regional to Global Environments (FIREX) laboratory studies. Based on quantified emissions factors, we estimate that our improved representation captures 72 % of emitted, identified NMOG carbon mass and 49 % of OH reactivity from savanna and temperate forest fires, a substantial increase from the standard model (49 % of mass, 28 % of OH reactivity). We evaluate fire NMOGs in our model with observations from the Amazon Tall Tower Observatory (ATTO) in Brazil, Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) and DC3 in the US, and Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) in boreal Canada. We show that NMOGs, including furan, are well simulated in the eastern US with some underestimates in the western US and that adding fire emissions improves our ability to simulate ethene in boreal Canada. We estimate that fires provide 15 % of annual mean simulated surface OH reactivity globally, as well as more than 75 % over fire source regions. Over continental regions about half of this simulated fire reactivity comes from NMOG species. We find that furans and ethene are important globally for reactivity, while phenol is more important at a local level in the boreal regions. This is the first global estimate of the impact of fire on atmospheric reactivity.