Comparisons of in situ and long path measurements of NO2 in urban plumes
Comparisons of in situ and long path measurements of NO2 in urban plumes
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城市羽流中 NO2 的原位测量和长路径测量的比较
DOI：
10.1029/2003jd003559
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发表时间：
2003
影响因子：
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通讯作者：
B. Alicke
中科院分区：
文献类型：
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作者：
J. Thornton;P. Wooldridge;R. Cohen;E. Williams;D. Hereid;F. Fehsenfeld;J. Stutz;B. Alicke
[1] 1999 年南方氧化研究期间，在田纳西州纳什维尔的科妮莉亚堡机场对 NO2 进行了测量，使用了三种不同的技术：光解为 NO，然后进行化学发光 (PCL)、激光诱导荧光 (LIF) 和微分光学吸收光谱 (DOAS)。这是 1999 年南方氧化研究期间对这些技术进行的非正式比较。 PCL 和 LIF 仪器连接到一个公共歧管，该歧管在 10 米高的塔顶进行采样。 DOAS 仪器对 1.37 km 长的光路进行采样，其端点位于距地面 2 和 35 m 处。测量的 NO2 混合比例范围为 0.75 ppbv 至 60 ppbv 以上，中值接近 3 ppbv。虽然初步数据分析显示 LIF 和 PCL 仪器之间的总体一致性在 1% 以内（最小二乘斜率 = 0.99；r2 = 0.98），但随后的分析显示 PCL 数据存在约 12% 的不连续变化，这一点通过与 DOAS 数据的比较得到证实。 PCL 入口系统泄漏可能是原因。对受影响的 PCL 数据进行调整后，所有一致测量结果的比较显示出高度相关性 (r2 > 0.99)，总体一致性在 5% 以内。对 PCL NO2 与 LIF NO2 比率的分析表明，超过 90% 的单个数据点在总组合仪器不确定性范围内一致。然而，短期内的比较比整个活动期间的平均值更精确。我们将此归因于改进 PCL 仪器数据缩减程序的需要。一年后，这两个现场仪器也在德克萨斯州休斯顿同时运行，得到了类似的结果。
[1] Measurements of NO2 were taken at Cornelia Fort Airpark in Nashville, TN, during the 1999 Southern Oxidant Study using three different techniques: photolysis to NO followed by chemiluminescence (PCL), laser-induced fluorescence (LIF), and differential optical absorption spectroscopy (DOAS). This was an informal comparison of these techniques conducted during the 1999 Southern Oxidant Study. The PCL and LIF instruments were connected to a common manifold that sampled at the top of a 10-m-walkup tower. The DOAS instrument sampled over a 1.37-km-long light path with end points at 2 and 35 m above ground. The range of NO2 mixing ratios measured was 0.75 ppbv to over 60 ppbv and the median value was nearly 3 ppbv. While preliminary data analysis showed overall agreement between the LIF and PCL instruments to within 1% (least squares slope = 0.99; r2 = 0.98), subsequent analysis revealed a discontinuous shift of about 12% in the PCL data, which was confirmed by comparison to the DOAS data. A leak in the PCL inlet system was the likely cause. After adjustment of the affected PCL data, a comparison of all the coincident measurements showed high correlation (r2 > 0.99) and overall agreement to within 5%. Analysis of the ratios of PCL NO2 to LIF NO2 showed that greater than 90% of individual data points agree to within the total combined instrumental uncertainties. However, the comparison over short time periods is more precise than the average over the campaign. We attribute this to the need for improved PCL instrument data reduction procedures. The two in situ instruments were also operated side by side a year later in Houston, TX, with similar results.