Ground and Airborne U.K. Measurements of Nitryl Chloride: An Investigation of the Role of Cl Atom Oxidation at Weybourne Atmospheric Observatory
Ground and Airborne U.K. Measurements of Nitryl Chloride: An Investigation of the Role of Cl Atom Oxidation at Weybourne Atmospheric Observatory
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DOI：
10.1002/2017jd026624
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发表时间：
2017-10
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影响因子：
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通讯作者：
T. Bannan;A. Bacak;Michael Le Breton;M. Flynn;B. Ouyang;M. McLeod;Roderic L. Jones;T. L. Malkin;L. Whalley;D. Heard;B. Bandy;M. Khan;D. Shallcross;C. Percival
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文献类型：
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作者：
T. Bannan;A. Bacak;Michael Le Breton;M. Flynn;B. Ouyang;M. McLeod;Roderic L. Jones;T. L. Malkin;L. Whalley;D. Heard;B. Bandy;M. Khan;D. Shallcross;C. Percival
2013年3月至4月，Weybourne大气观测站（WAO）使用四重化学电离质谱仪测量了一氧化氮（ClNO2）。WAO是一个农村沿海地区，氮氧化物浓度普遍较低，是一种对ClNO2生产研究不足的地区。ClNO2的浓度超过了检测限（0.8 ppt），在每个晚上的活动，也与剑桥宽带腔增强吸收光谱仪同时测量的N2O5的浓度。此处报告的ClNO2峰值浓度为65 ppt。还报告了在WAO附近的清晨至中午航班的ClNO2垂直分布，显示低海拔浓度升高。所观察到的ClNO2的光解和箱模型，利用修改后的主化学机制，包括氯化学计算氯原子浓度。该模型利用了2004年第二个对流层有机化学项目在同一地点和同一时间的大量VOC。从这三组测量的挥发性有机化合物（烷烃，烯烃和炔烃）的氧化OH自由基，Cl原子和O3的相对重要性进行比较。由于观察到的ClNO2浓度低得多，即使在ClNO2产量最大的夜晚之后，Cl原子氧化在此时和总氧化位置通常被认为是微不足道的。
Nitryl chloride (ClNO2) measurements from the Weybourne Atmospheric Observatory (WAO) are reported from March to April 2013 using a quadruple chemical ionization mass spectrometer with the I− ionization scheme. WAO is a rural coastal site with generally low NOx concentrations, a type of location poorly studied for ClNO2 production. Concentrations of ClNO2 exceeded that of the limit of detection (0.8 ppt) on each night of the campaign, as did concentrations of N2O5, which was also measured simultaneously with the Cambridge Broadband Cavity Enhanced Absorption Spectrometer. A peak concentration of 65 ppt of ClNO2 is reported here. Vertical profiles of ClNO2 from early‐ to middle‐morning flights in close proximity to WAO are also reported, showing elevated concentrations at low altitude. The photolysis of observed ClNO2 and a box model utilizing the Master Chemical Mechanism modified to include chlorine chemistry was used to calculate Cl atom concentrations. This model utilized numerous VOCs from the second Tropospheric Organic Chemistry project in 2004, at the same location and time of year. From this the relative importance of the oxidation of three groups of measured VOCs (alkanes, alkenes, and alkynes) by OH radicals, Cl atoms, and O3 is compared. Cl atom oxidation was deemed generally insignificant at this time and location for total oxidation due to the much lower concentration of ClNO2 observed, even following the night of greatest ClNO2 production.