Evidence of Reactive Aromatics As a Major Source of Peroxy Acetyl Nitrate over China

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• 作者：Zhen Liu ; Yuhang Wang ; Dasa Gu ; Chun Zhao ; L. Gregory Huey ; Robert Stickel ; Jin Liao ; Min Shao ; Tong Zhu ; Limin Zeng ; Shaw-Chen Liu ; Chih-Chung Chang ; Antonio Amoroso ; Francesca Costabile
• 刊名：Environmental Science & Technology
• 出版年：2010
• 出版时间：September 15, 2010
• 年：2010
• 卷：44
• 期：18
• 页码：7017-7022
• 全文大小：236K
• 年卷期：v.44,no.18(September 15, 2010)
• ISSN：1520-5851

文摘

We analyze the observations of near-surface peroxy acetyl nitrate (PAN) and its precursors in Beijing, China in August of 2007. The levels of PAN are remarkably high (up to 14 ppbv), surpassing those measured over other urban regions in recent years. Analyses employing a 1-D version of a chemical transport model (Regional chEmical and trAnsport Model, REAM) indicate that aromatic non-methane hydrocarbons (NMHCs) are the dominant (55−75%) PAN source. The major oxidation product of aromatics that produces acetyl peroxy radicals is methylglyoxal (MGLY). PAN and O₃ in the observations are correlated at daytime; aromatic NMHCs appear to play an important role in O₃ photochemistry. Previous NMHC measurements indicate the presence of reactive aromatics at high levels over broad polluted regions of China. Aromatics are often ignored in global and (to a lesser degree) regional 3D photochemical transport models; their emissions over China as well as photochemistry are quite uncertain. Our findings suggest that critical assessments of aromatics emissions and chemistry (such as the yields of MGLY) are necessary to understand and assess ozone photochemistry and regional pollution export in China.