Nighttime Chemical Transformation in Biomass Burning Plumes: A Box Model Analysis Initialized with Aircraft Observations
Nighttime Chemical Transformation in Biomass Burning Plumes: A Box Model Analysis Initialized with Aircraft Observations
复制标题
DOI：
10.1021/acs.est.8b05359
复制
发表时间：
2019-03-05
影响因子：
11.4
通讯作者：
Brown, Steven S.
中科院分区：
文献类型：
--
作者：
Decker, Zachary C. J.;Zarzana, Kyle J.;Brown, Steven S.
生物质燃烧（BB）是大气中活性化合物的一大来源。虽然人们已经对BB辐射的白天光化学进行了一些详细的研究，但对夜间反应的关注很少，尽管可能存在大量的氧化和异质化学。在这里，我们首次利用NOAA WP-3D飞机在2013年东南Nexus （SENEX）活动期间的观测数据对夜间飞机拦截的农业BB羽流进行了分析。我们将这些观测结果与详细的化学箱模型相结合，研究了氧化剂（NO3、N2O5、O-3和OH）和BB挥发性有机化合物（BBVOCs）的形成和命运，使用了农业燃烧（稻草）和西部野火（黄松）的排放代表。现场观测表明，NO3产量约为1 ppbv，而NO3和N2O5的产量为或低于3 ppbv，表明NO3/N2O5反应性快速。模型分析表明，b> 99%的NO3/ N2O5损失是由于BBVOC + NO3反应，而不是由于气溶胶对N2O5的吸收。秸秆和黄松火灾的夜间BBVOC氧化以NO3为主（分别为72,53%），但O-3氧化显著（25,43%），导致最活跃的BBVOC和NO2在夜间消耗约5S%。
Biomass burning (BB) is a large source of reactive compounds in the atmosphere. While the daytime photochemistry of BB emissions has been studied in some detail, there has been little focus on nighttime reactions despite the potential for substantial oxidative and heterogeneous chemistry. Here, we present the first analysis of nighttime aircraft intercepts of agricultural BB plumes using observations from the NOAA WP-3D aircraft during the 2013 Southeast Nexus (SENEX) campaign. We use these observations in conjunction with detailed chemical box modeling to investigate the formation and fate of oxidants (NO3, N2O5, O-3, and OH) and BB volatile organic compounds (BBVOCs), using emissions representative of agricultural burns (rice straw) and western wildfires (ponderosa pine). Field observations suggest NO3 production was approximately 1 ppbv while NO3 and N2O5 were at or below 3 pptv, indicating rapid NO3/N2O5 reactivity. Model analysis shows that >99% of NO3/ N2O5 loss is due to BBVOC + NO3 reactions rather than aerosol uptake of N2O5. Nighttime BBVOC oxidation for rice straw and ponderosa pine fires is dominated by NO3 (72, 53%, respectively) but O-3 oxidation is significant (25, 43%), leading to roughly 5S% overnight depletion of the most reactive BBVOCs and NO2.