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Frequency-Comb-Based Remote Sensing of Greenhouse Gases over Kilometer Air Paths



Greg B. Rieker, Fabrizio R. Giorgetta, William C. Swann, Jonathan Kofler, Alexander M. Zolot, Laura C. Sinclair, Esther Baumann, Christopher L. Cromer, G. Petron, Colm Sweeney, P P. Tans, Ian R. Coddington, Nathan R. Newbury


We demonstrate frequency comb tooth-by-tooth measurements of atmospheric gas absorption across a 2-km, turbulent, open-air path through coherent dual-comb spectroscopy. High accuracy, high signal-to-noise transmission spectra are acquired spanning 5990 to 6260 cm-1 (1600 to 1670 nm) at 0.0033 cm-1 point spacing and covering ~700 absorption features from CO2, CH4, H2O, HDO, and 13CO2. The fitted concentrations and path-averaged temperature yield dry mixing ratios. These are compared with a nearby point sensor under well-mixed conditions to evaluate the accuracy of current spectral absorption models for real atmospheres. In poorly mixed conditions, time-resolved data demonstrate tracking of strong variations in path-averaged mixing ratios. Measurement accuracy is limited by current spectral databases. A precision of


molecular spectroscopy, frequency combs, greenhouse gases


Rieker, G. , Giorgetta, F. , Swann, W. , Kofler, J. , Zolot, A. , Sinclair, L. , Baumann, E. , Cromer, C. , Petron, G. , Sweeney, C. , Tans, P. , Coddington, I. and Newbury, N. (2014), Frequency-Comb-Based Remote Sensing of Greenhouse Gases over Kilometer Air Paths, Optica, [online], (Accessed June 21, 2024)


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Created October 29, 2014, Updated November 10, 2018