Sensitivity analyses of OH missing sinks over Tokyo metropolitan area in the summer of 2007
Sensitivity analyses of OH missing sinks over Tokyo metropolitan area in the summer of 2007
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DOI：
10.5194/acp-9-8975-2009
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发表时间：
2009-11
影响因子：
6.3
通讯作者：
S. Chatani;N. Shimo;S. Matsunaga;Y. Kajii;Shungo;Kato;Yoshihiro Nakashima;K. Miyazaki;Koichiro Ishii;Hiroyuki Ueno
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文献类型：
--
作者：
S. Chatani;N. Shimo;S. Matsunaga;Y. Kajii;Shungo;Kato;Yoshihiro Nakashima;K. Miyazaki;Koichiro Ishii;Hiroyuki Ueno
抽象的。OH反应性是反映大气中光化学反应影响的重要指标之一。2007年夏天，在东京都市区的中心进行了一次观测活动，以测量OH反应性。直接由激光诱导的泵和探针技术测量的总OH反应性高于从浓度和反应速率系数计算的OH反应性的总和在这场运动中测量的个别物种。然后，三维空气质量模拟已经进行了评估的模拟性能的总OH反应性，包括“失踪汇”，这对应于测量和计算的总OH反应性之间的差异。模拟的OH反应性被大大低估，因为挥发性有机化合物（VOCs）和丢失的汇的OH反应性被低估。当比例因子被施加到输入的排放和边界浓度，一个很好的协议之间观察到的模拟和测量的挥发性有机化合物浓度。然而，模拟的OH反应失踪汇仍然被低估。因此，通过敏感性分析研究了未识别的缺失汇的影响。在假定未知的二次产品是未查明的失踪汇的原因的情况下，它们往往会抑制二次气溶胶成分的形成，并促进臭氧的形成。在假定未查明的一次排放物种是未查明的汇缺失的原因的情况下，可能会观察到各种影响，这些影响可作为二次有机气溶胶的前体，并大大增加二次有机气溶胶的形成。失踪汇被认为在东京都区的大气中起着重要的作用。
Abstract. OH reactivity is one of key indicators which reflect impacts of photochemical reactions in the atmosphere. An observation campaign has been conducted in the summer of 2007 at the heart of Tokyo metropolitan area to measure OH reactivity. The total OH reactivity measured directly by the laser-induced pump and probe technique was higher than the sum of the OH reactivity calculated from concentrations and reaction rate coefficients of individual species measured in this campaign. And then, three-dimensional air quality simulation has been conducted to evaluate the simulation performance on the total OH reactivity including "missing sinks", which correspond to the difference between the measured and calculated total OH reactivity. The simulated OH reactivity is significantly underestimated because the OH reactivity of volatile organic compounds (VOCs) and missing sinks are underestimated. When scaling factors are applied to input emissions and boundary concentrations, a good agreement is observed between the simulated and measured concentrations of VOCs. However, the simulated OH reactivity of missing sinks is still underestimated. Therefore, impacts of unidentified missing sinks are investigated through sensitivity analyses. In the cases that unknown secondary products are assumed to account for unidentified missing sinks, they tend to suppress formation of secondary aerosol components and enhance formation of ozone. In the cases that unidentified primary emitted species are assumed to account for unidentified missing sinks, a variety of impacts may be observed, which could serve as precursors of secondary organic aerosols (SOA) and significantly increase SOA formation. Missing sinks are considered to play an important role in the atmosphere over Tokyo metropolitan area.