Reaction between CH3O2 and BrO radicals: a new source of upper troposphere lower stratosphere hydroxyl radicals.
Reaction between CH3O2 and BrO radicals: a new source of upper troposphere lower stratosphere hydroxyl radicals.
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DOI：
10.1021/jp5108203
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发表时间：
2015-05
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通讯作者：
D. Shallcross;K. Leather;A. Bacak;P. Xiao;Edmond P. F. Lee;M. Ng;D. Mok;J. Dyke;R. Hossaini;Martyn P. Chipper;eld;M. Khan;C. Percival
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作者：
D. Shallcross;K. Leather;A. Bacak;P. Xiao;Edmond P. F. Lee;M. Ng;D. Mok;J. Dyke;R. Hossaini;Martyn P. Chipper;eld;M. Khan;C. Percival
在过去的二十年里，已经出现了在对流层上层测量的羟基自由基水平往往被模型低估，导致有失踪的来源断言。在这里，我们报告了CH 3 O2和BrO自由基之间反应的动力学和产物的实验室研究，表明这可能是羟基自由基的重要新来源：BrO + CH 3 O2 →产物（1）。k（T）的Arrhenius形式随温度变化的值为k1 =（2.42-0.72+1.02）× 10-14 exp[（1617 ± 94）/T] cm ~ 3·molecule ~（-1）·s ~（-1）。此外，CH 2 OO和HOBr被认为是主要产物。全球模式的结果表明，分解的H2 COO形成OH可能会导致在中纬度地区的对流层上部和平流层下部的OH的增强高达20%，在2-9%的增强从模式积分推断。此外，反应1有助于将BrO转化为HOBr，并减缓平流层下部的极地臭氧损失。
Over the last two decades it has emerged that measured hydroxyl radical levels in the upper troposphere are often underestimated by models, leading to the assertion that there are missing sources. Here we report laboratory studies of the kinetics and products of the reaction between CH3O2 and BrO radicals that shows that this could be an important new source of hydroxyl radicals:BrO + CH3O2 → products (1). The temperature dependent value in Arrhenius form of k(T) is k1 = (2.42–0.72+1.02) × 10–14 exp[(1617 ± 94)/T] cm3 molecule–1 s–1. In addition, CH2OO and HOBr are believed to be the major products. Global model results suggest that the decomposition of H2COO to form OH could lead to an enhancement in OH of up to 20% in mid-latitudes in the upper troposphere and in the lower stratosphere enhancements in OH of 2–9% are inferred from model integrations. In addition, reaction 1 aids conversion of BrO to HOBr and slows polar ozone loss in the lower stratosphere.