- 1Université du Littoral Côte d’Opale, Laboratoire de Physicochimie de l’Atmosphère, Dunkerque, France
- 2Jiangsu Key Laboratory of Advanced Laser Materials and Devices, Jiangsu Normal University, China
- 3Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, China
- 4State Key Laboratory of Quantum Optics and Quantum Optics Devices, ILS, Shanxi University, Taiyuan, China
Ocean-atmosphere gas exchange plays a critical role in the global carbon cycle, as the ocean acts as both a major sink and source of atmospheric CO2. This exchange process regulates the Earth's carbon balance and influences climate systems on a global scale. Understanding the mechanisms of CO2 absorption and release at the ocean surface is essential for accurately assessing the ocean’s contribution to carbon fluxes [1].
The present work introduces the development of a optical sensor based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) for measurement of CO2 dissolved in seawater. This approach enables real-time measurement of CO2 concentrations in seawater for evaluation of CO2 distribution and study of exchange processes between ocean and atmosphere. The developed sensing platform involves a 2008 nm distributed feedback laser coupled to a compact 30-m multipass cell with 7-circle spot dense pattern [2] using wavelength modulation spectroscopy approach [Figure 1]. CO2 dissolved in seawater is extracted using a custom-designed membrane contactor extraction device.
Figure 1. Experimental measurements of 2f absorption spectra of CO2 in air and dissolved in seawater.
Performance of the CO2 sensing platform, experimental details and the preliminary results will be discussed and presented.
Acknowledgments
This work is partially supported by the French national research agency (ANR) under the Labex CaPPA (ANR-10-LABX-005) and the ICAR-HO2 (ANR-20-CE04-0003) contracts, the EU H2020-ATMOS project (Marie Skłodowska-Curie grant agreement No 872081), the regional CPER ECRIN program, and the National Natural Science Foundation of China (Grant No. 62235010). The Région Hauts-de-France and the Pôle Métropolitain de la Côte d’Opale are gratefully acknowledged for PhD scholarship support.
References
[1] Tim DeVries, “The ocean carbon cycle”, Annual Review of Environment and Resources 47 (2022) 317-341.
[2] Kun Liu, Lei Wang, Tu Tan, Guishi Wang, Weijun Zhang, Weidong Chen, Xiaoming Gao, “Highly sensitive detection of methane by near-infrared laser absorption spectroscopy using a compact dense-pattern multipass cell”, Sensors and Actuators B: Chemical 220 (2015) 1000-1005.
How to cite: Hu, Y., Augustin, P., Wang, J., Liu, K., Cui, R., Wu, H., Dong, L., Gao, X., Fourmentin, M., Nguyen Ba, T., and Chen, W.: Optical sensing platform based on tunable laser absorption spectroscopy for the measurement of carbon dioxide dissolved in seawater, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4475, https://doi.org/10.5194/egusphere-egu25-4475, 2025.
