Laser heterodyne radiometers (LHR) for in situ ground-based remote sensing of greenhouse gases in the atmospheric column
- 1Laboratoire de Physicochimie de l'Atmosphère / Université du Littoral Côte d'Opale - 59140 Dunkerque, France
- 2Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 230031 Hefei, China
- 3LERMA, Université Pierre et Marie Curie, 75252 Paris, France
Measurements of vertical concentration profiles of greenhouse gases (GHGs) is extremely important for our understanding of regional air quality and global climate change trends. In this context, laser heterodyne radiometer (LHR) technique has been developed [1-5] for ground-based remote measurements of GHGs in the atmospheric column.
Solar radiation undergoing absorption by multi-species in the atmosphere is coupled into a LHR instrument where the sunlight is mixed with a local oscillator (LO), being usually a tunable laser source, in a fast photodetector. Beating note at radio frequency (RF) resulted from this photomixing contains absorption information of the LO-targeted molecules. Scanning the LO frequency across the target molecular absorption lines allows one to extract the corresponding absorption features from the total absorption of the solar radiation by all molecules in the atmospheric column. Near-IR (~1.5 µm) and mid-IR (~8 µm) [6] LHRs have been recently developed in the present work. Field campaigns have been performed on the roof of the platform of IRENE in Dunkerque (51.05°N/2.34°E).
The developed LHR instruments as well as the preliminary results of their applications to the measurements of CH4, N2O, CO2 (including 13CO2/12CO2), H2O vapor (and its isotopologue HDO) in the atmospheric column will be presented and discussed.
Acknowledgments The authors thank the financial supports from the LABEX CaPPA project (ANR-10-LABX005), the MABCaM (ANR-16-CE04-0009) and the MULTIPAS (ANR-16-CE04-0012) contracts, as well as the CPER CLIMIBIO program. S. F. thanks the program Labex CaPPA and the "Pôle Métropolitain de la Côte d’Opale" (PMCO) for the PhD fellowship support.
References
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[6] F. Shen, P. Jeseck, Y. Te, T. Tan, X. Gao, E. Fertein, and W. Chen, Geophys. Res. Abstracts, 20 (2018) EGU2018-79
How to cite: Wang, J., Shen, F., Tan, T., Cao, Z., Gao, X., Jeseck, P., Te, Y., and Chen, W.: Laser heterodyne radiometers (LHR) for in situ ground-based remote sensing of greenhouse gases in the atmospheric column, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-22368, https://doi.org/10.5194/egusphere-egu2020-22368, 2020
