A Relaxed Eddy Accumulation (REA)-GC/MS system for the determination of halocarbon fluxes
A Relaxed Eddy Accumulation (REA)-GC/MS system for the determination of halocarbon fluxes
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DOI：
10.5194/amt-2-437-2009
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发表时间：
2009-08
影响因子：
3.8
通讯作者：
K. Hornsby;M. Flynn;J. Dorsey;M. Gallagher;R. Chance;C. E. Jones;L. Carpenter
中科院分区：
文献类型：
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作者：
K. Hornsby;M. Flynn;J. Dorsey;M. Gallagher;R. Chance;C. E. Jones;L. Carpenter
抽象的。极短寿命卤化碳（VSLH）在卤素原子向对流层和平流层低层的运输中发挥着重要作用。在这里，我们描述了使用气相色谱法与质谱仪 (REA-GC/MS) 结合的松弛涡流累积系统的开发，以确定 VSLH 的表面通量，时间分辨率约为 0.5 小时。实验室测试表明，向上、向下和死区流动路径使用共用入口会导致向上和向下移动的气团混合，因此我们建议使用单独的入口。改进后的系统在爱尔兰西海岸的梅斯海德进行了现场试验，那里有茂密的海带床，已知会释放一系列卤化碳。在 2007 年 9 月中旬的 16 小时内，CH2Br2 CH2ICl 和 CH2IBr 获得的平均通量分别为 16.1±1.8、4.0±0.54 和 1.2±0.2 nmol m−2 day−1。
Abstract. Very short lived halocarbons (VSLH) play an important role in the transport of halogen atoms to the troposphere and lower stratosphere. Here we describe the development of a relaxed eddy accumulation system using gas chromatography coupled to a mass spectrometer (REA-GC/MS) to determine surface fluxes of VSLH with a time resolution of about 0.5 h. Laboratory tests showed that use of a common inlet for upward, downward and deadband flow paths resulted in mixing of upward and downward moving air masses, therefore we recommend the use of separate inlets. The modified system underwent field trials at Mace Head on the west coast of Ireland, where there are dense kelp beds known to emit a range of halocarbons. Over a 16 h period in mid-September 2007, the mean fluxes obtained were 16.1±1.8, 4.0±0.54 and 1.2±0.2 nmol m−2 day−1 for CH2Br2 CH2ICl and CH2IBr, respectively.