Open AccessWater isotope ratio ( δ 2 H and δ 18 O) measurements in atmospheric moisture using an optical feedback cavity enhanced absorption laser spectrometer
Author(s) -
Ian Rosario Q.,
Romanini Daniele,
Cattani Olivier,
Meijer Harro A. J.,
Kerstel Erik R. Th.
Publication year - 2010
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2009jd012895
Subject(s) - water vapor , troposphere , mixing ratio , stratosphere , atmospheric sciences , environmental science , water cycle , relative humidity , moisture , atmosphere (unit) , chemistry , isotope , spectrometer , deuterium , analytical chemistry (journal) , environmental chemistry , meteorology , geology , physics , atomic physics , optics , ecology , quantum mechanics , biology , organic chemistry
Water vapor isotopes represent an innovative and excellent tool for understanding complex mechanisms in the atmospheric water cycle over different time scales, and they can be used for a variety of applications in the fields of paleoclimatology, hydrology, oceanography, and ecology. We use an ultrasensitive near‐infrared spectrometer, originally designed for use on airborne platforms in the upper troposphere and lower stratosphere, to measure the water deuterium and oxygen‐18 isotope ratios in situ , in ground‐level tropospheric moisture, with a high temporal resolution (from 300 s down to less than 1 s). We present some examples of continuous monitoring of near‐surface atmospheric moisture, demonstrating that our infrared laser spectrometer could be used successfully to record high‐concentration atmospheric water vapor mixing ratios in continuous time series, with a data coverage of ∼90%, interrupted only for daily calibration to two isotope ratio mass spectrometry–calibrated local water standards. The atmospheric data show that the water vapor isotopic composition exhibits a high variability that can be related to weather conditions, especially to changes in relative humidity. Besides, the results suggest that observed spatial and temporal variations of the stable isotope content of atmospheric water vapor are strongly related to water vapor transport in the atmosphere.