title: [Measurements of stable isotopes in atmospheric CO2 and H2O by open-path Fourier transform infrared spectrometry].
abstract: The development of spectroscopic techniques has offered continuous measurement of stable isotopes in the ambient air. The method of measuring environmental stable isotopes based on Fourier transform infrared spectrometry (FTIR) is described. In order to verify the feasibility of the method for continuous measurement of the stable isotopes, an open-path FTIR system was used to measure stable isotopes of CO2 and H2O in ambient air directly in a seven-day field experiment, including 12CO2, 3CO2, H2 16O and HD16 O. Also, the time course of carbon isotopic ratio delta13 C and deuterium isotope composition deltaD was calculated. The measurement precision is about 1.08 per thousand for delta13 C and 1.32 per thousand for deltaD. The measured stable isotopes of CO2 and H2O were analyzed on different time scales by Keeling plot methods, and the deuterium isotopic ratios of evapotranspiration were determined. The results of the field experiment demonstrate the potential of the open-path FTIR system for continuous measurement of stable isotopes in the air.
authors.affiliation: School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China. wwang@aiofm.ac.cn
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Wen-Qing
authors.initials: WQ
authors.lastname: Liu
authors.forename: Tian-Shu
authors.initials: TS
authors.lastname: Zhang