Acetone in the free troposphere and lower stratosphere: Aircraft‐based CIMS and GC measurements over the North Atlantic and a first comparison
Acetone in the free troposphere and lower stratosphere: Aircraft‐based CIMS and GC measurements over the North Atlantic and a first comparison
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自由对流层和平流层低层中的丙酮：北大西洋上空基于飞机的 CIMS 和 GC 测量以及首次比较
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
H. Singh
中科院分区：
文献类型：
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作者：
K. Wohlfrom;T. Hauler;F. Arnold;H. Singh
1997年秋季，在POLINAT-2/Sonex运动的框架内，使用机载CIMS(化学电离质谱仪)和GC(气相色谱)仪器在北大西洋上空的自由对流层和平流层下部测量了丙酮。这些测量包括28次飞行，覆盖的高度从2.4到12.5公里，地理纬度从20到69°N。这些数据是迄今为止公布的对自由对流层和平流层低层丙酮的最广泛测量。首先对CIMS和GC方法进行了比较。在相同的气团中，两台仪器获得的丙酮数据的一致性在50%以内，这与引用的不确定度限值一致。对所有飞行的检查显示，对流层上层的丙酮在200到2200pptv之间变化很大，平均值约为600pptv。相比之下，在较低的平流层，丙酮丰度的变化要小得多，大多在100到200pptv左右。在对流层上层，体积混合比超过1000PPTV和高达2200PPTV的富丙酮气团出人意料地频繁出现。这些气团可能最近与大陆行星边界层接触，在那里它们从地面来源吸收了丙酮和/或丙酮前体气体。
Acetone was measured in the free troposphere and lower stratosphere over the North Atlantic by aircraft‐based CIMS (Chemical lonization Mass Spectrometry) and GC (Gas Chromatography) instruments in fall 1997 within the framework of the POLINAT‐2/SONEX campaigns. The measurements included 28 flights covering altitudes from 2.4 to 12.5 km, and geographic latitudes from 20 to 69°N. The data are the most extensive measurements of acetone in the free troposphere and lower stratosphere published to date. A first comparison of the CIMS and the GC method is presented. The acetone data obtained by both instruments in the same air masses agree within 50% which is consistent with the uncertainty limits quoted. An inspection of all flights reveals upper tropospheric acetone to vary very substantially between 200 and 2200 pptv with a mean value of about 600 pptv. By contrast, in the lower stratosphere the acetone abundance is much less variable and is mostly around 100 to 200 pptv. Acetone rich air masses with volume mixing ratios exceeding 1000 pptv and reaching up to 2200 pptv were surprisingly frequently encountered in the upper troposphere. Probably these air masses had recent contact with the continental planetary boundary layer where they took up acetone and/or acetone precursor gases from ground‐level sources.