Intercomparison of in situ CRDS and CEAS for measurements of atmospheric N2O5in Beijing, China
Intercomparison of in situ CRDS and CEAS for measurements of atmospheric N2O5in Beijing, China
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中国北京大气 N2O5 现场 CRDS 与 CEAS 测量对比
DOI：
10.1016/j.scitotenv.2017.08.302
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发表时间：
2018
影响因子：
9.8
通讯作者：
Wang Dan
中科院分区：
文献类型：
--
作者：
Li Zhiyan;Hu Renzhi;Xie Pinhua;Wang Haichao;Lu Keding;Wang Dan
五氧化二氮（N2 O 5）是夜间大气中起关键作用的基本微量气体之一。不同的N2 O 5测量方法的相互比较和验证对于确定这些方法的真实准确性是重要的。2016年2月21日至2016年3月4日，利用腔衰荡光谱仪（CRDS）和腔增强吸收光谱仪（CEAS）对中国科学院大学校园内的N2 O 5进行了测量。CEAS仪器的检测限在30 s间隔时为1.6 ppt（1σ），CRDS仪器的检测限在10 s时间分辨率时为3.9 ppt（1σ）。在本研究中，对两种仪器的1 min观察结果进行了比较。两个数据集在其不确定性范围内显示出良好的一致性，绝对偏移为15.6 ppt，斜率为0.94，相关系数R2= 0.97。一般来说，CRDS和CEAS仪器测量N2 O 5的差异可以通过它们的组合测量不确定度来解释。然而，高相对湿度（> 60%）和高PM2.5浓度（> 200 μg/m3）可能会导致差异。CRDS和CEAS仪器的测量结果之间的良好一致性证明了这两种仪器能够以高灵敏度准确测量N2 O 5。
Dinitrogen pentoxide (N2O5) is one of the basic trace gases which plays a key role in nighttime atmosphere. An intercomparison and validation of different N2O5measurement methods is important for determining the true accuracy of these methods. Cavity ring down spectroscopy (CRDS) and cavity enhanced absorption spectrometer (CEAS) were used to measure N2O5at the campus of the University of Chinese Academy of Sciences (UCAS) from February 21, 2016 to March 4, 2016. The detection limits were 1.6 ppt (1σ) at 30 s intervals for the CEAS instrument and 3.9 ppt (1σ) at 10 s time resolution for the CRDS instrument respectively. In this study, a comparison of the 1 min observations from the two instruments was presented. The two data sets showed a good agreement within their uncertainties, with an absolute shift of 15.6 ppt, slope of 0.94 and a correlation coefficient R2= 0.97. In general, the difference between the CRDS and CEAS instruments for N2O5measurement can be explained by their combined measurement uncertainties. However, high relative humidity (> 60%) and high PM2.5 concentration (> 200 μg/m3) may contribute to the discrepancies. The excellent agreement between the measurement by the CRDS and CEAS instruments demonstrates the capability of the two instruments for accurately measuring N2O5with high sensitivity.