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Open-path measurement of stable water isotopologues using mid-infrared dual-comb spectroscopy



Daniel Herman, Griffin Mead, Fabrizio Giorgetta, Esther Baumann, Nathan Malarich, Brian Washburn, Nathan R. Newbury, Ian Coddington, Kevin Cossel


We present an open-path mid-infrared dual-comb spectrometer (DCS) capable of precise measurement of the stable water isotopologues H216O and HD16O. This system runs in a remote configuration at a rural test site with high uptime and achieves a precision of <2‰ on δD in 1000 seconds. We compare the δD from the DCS to measurements from the National Ecological Observatory Network (NEON) isotopologue point sensor network. Using data from a multi-month campaign, we calculate that the mean difference between DCS δD and NEON δD is <2‰ with a standard deviation of 18‰, which demonstrates the inherent accuracy of DCS measurements over a variety of atmospheric conditions. Precise and accurate open-path measurements of stable water isotopologues using DCS will enable wider development of ecological monitoring networks aimed at understanding regional and synoptic scale water transport.
Atmospheric Measurement Techniques


Frequency Combs, Atmospheric Spectroscopy, Meteorology


Herman, D. , Mead, G. , Giorgetta, F. , Baumann, E. , Malarich, N. , Washburn, B. , Newbury, N. , Coddington, I. and Cossel, K. (2023), Open-path measurement of stable water isotopologues using mid-infrared dual-comb spectroscopy, Atmospheric Measurement Techniques, [online],, (Accessed May 29, 2024)


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Created September 8, 2023, Updated September 27, 2023