期刊
ATMOSPHERIC CHEMISTRY AND PHYSICS
卷 9, 期 8, 页码 2635-2645出版社
COPERNICUS GESELLSCHAFT MBH
DOI: 10.5194/acp-9-2635-2009
关键词
-
资金
- EU project NitroEurope [017841]
- FORMAS
- Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning [21.4/2003-1410]
- Max Planck Society
As part of a field campaign in the framework of the Nitro Europe project, three different instruments for atmospheric ammonia (NH3) measurements were operated side-by-side on a managed grassland site in Switzerland: a modified Proton Transfer Reaction Mass Spectrometer (PTR-MS), a GRadient of AErosol and Gases Online Registrator (GRAEGOR), and an Automated Ammonia Analyzer (AiRRmonia). The modified PTR-MS approach is based on chemical ionization of NH3 using O-2(+) instead of H3O+ as ionizing agent, GRAEGOR and AiRRmonia measure NH4+ in liquids after absorption of gaseous NH3 in a rotating wet-annular denuder and through a gas permeable membrane, respectively. Bivariate regression slopes using uncorrected data from all three instruments ranged from 0.78 to 0.97 while measuring ambient NH3 levels between 2 and 25 ppbv during a 5 days intercomparison period. Correlation coefficients r(2) were in the range of 0.79 to 0.94 for hourly average mixing ratios. Observed discrepancies could be partly attributed to temperature effects on the GRAEGOR calibration. Bivariate regression slopes using corrected data were >0.92 with offsets ranging from 0.22 to 0.58 ppbv. The intercomparison demonstrated the potential of PTR-MS to resolve short-time NH3 fluctuations which could not be measured by the two other slow-response instruments. During conditions favoring condensation in inlet lines, the PTR-MS underestimated NH3 mixing ratios, underlining the importance of careful inlet designs as an essential component for any inlet-based instrument.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据