Tunable diode laser in-situ CH4 measurements aboard the CARIBIC passenger aircraft: instrument performance assessment
Tunable diode laser in-situ CH4 measurements aboard the CARIBIC passenger aircraft: instrument performance assessment
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CARIBIC 客机上的可调谐二极管激光器原位 CH4 测量：仪器性能评估
DOI：
10.5194/amt-7-743-2014
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发表时间：
2013
影响因子：
3.8
通讯作者：
T. Schuck
中科院分区：
文献类型：
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作者：
C. Dyroff;A. Zahn;S. Sanati;E. Christner;A. Rauthe;T. Schuck
抽象。介绍了一种用于CARIBIC客机上甲烷（CH 4）混合比自动月测量的激光光谱仪。该仪器基于商业快速温室气体分析仪（FGGA，洛斯加托斯研究所），其适于满足无人值守的机载操作所强加的要求。在实验室中对仪器稳定性、精密度、对H2O的交叉灵敏度和准确度进行了表征。对于机载操作，校准策略描述，利用CH 4测量在相同的飞行过程中采取的烧瓶样品。空气中的测量精度为2 ppb，10秒的平均值。在飞机巡航高度的精度为3.85 ppb。在飞机上升和下降期间，如果没有获得烧瓶样本，则仪器漂移的确定准确度较差，不确定度估计为12.4 ppb。对CH 4测量值进行了线性湿度偏差校正，这在对流层低层是最重要的。平均而言，校正偏差在2公里高度约为6.5 ppb，在巡航飞行高度可以忽略不计。本文介绍了103次长途飞行的观测结果，这些飞行跨越了北方半球对流层上部和平流层下部（UT/LMS）的很大一部分，在飞往南部非洲的航班上偶尔会穿越热带。这些精确的数据标志着全球最大的UT/LMS原位CH 4数据集。一个例子的示踪剂示踪剂与臭氧的相关性研究，突出了准确的跨对流层顶运输分析的可能性。
Abstract. A laser spectrometer for automated monthly measurements of methane (CH4) mixing ratios aboard the CARIBIC passenger aircraft is presented. The instrument is based on a commercial Fast Greenhouse Gas Analyser (FGGA, Los Gatos Res.), which was adapted to meet the requirements imposed by unattended airborne operation. It was characterised in the laboratory with respect to instrument stability, precision, cross sensitivity to H2O, and accuracy. For airborne operation, a calibration strategy is described that utilises CH4 measurements obtained from flask samples taken during the same flights. The precision of airborne measurements is 2 ppb for 10 s averages. The accuracy at aircraft cruising altitude is 3.85 ppb. During aircraft ascent and descent, where no flask samples were obtained, instrumental drifts can be less accurately determined and the uncertainty is estimated to be 12.4 ppb. A linear humidity bias correction was applied to the CH4 measurements, which was most important in the lower troposphere. On average, the correction bias was around 6.5 ppb at an altitude of 2 km, and negligible at cruising flight level. Observations from 103 long-distance flights are presented that span a large part of the northern hemispheric upper troposphere and lowermost stratosphere (UT/LMS), with occasional crossing of the tropics on flights to southern Africa. These accurate data mark the largest UT/LMS in-situ CH4 dataset worldwide. An example of a tracer-tracer correlation study with ozone is given, highlighting the possibility for accurate cross-tropopause transport analyses.
影响因子：
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作者：
M. Riese;F. Ploeger;A. Rap;B. Vogel;P. Konopka;M. Dameris;P. Forster
通讯作者：
M. Riese;F. Ploeger;A. Rap;B. Vogel;P. Konopka;M. Dameris;P. Forster