A dedicated robust instrument for water vapor generation at low humidity for use with a laser water isotope analyzer in cold and dry polar regions

• Published in: Atmospheric Measurement Techniques
• Main Authors: Leroy-Dos Santos, Christophe, Casado, Mathieu, Prié, Frédéric, Jossoud, Olivier, Kerstel, Erik, Farradèche, Morgane, Kassi, Samir, Fourré, Elise, Landais, AMAELLE
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Laboratoire Interdisciplinaire de Physique Saint Martin d’Hères (LIPhy ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Agence Nationale de la Recherche, ANR Institut Polaire Français Paul Emile Victor, IPEV: 1110, 1205 Prince Albert II of Monaco Foundation: 2487, Financial support. This research has been supported by the Prince Albert II of Monaco Foundation: 2487, Acknowledgements. The development presented in this paper was largely inspired by the initial PhD work of Janek Landsberg, which we gratefully acknowledge here. The research leading to these results has received funding from the Prince Albert II of Monaco Foundation “ANTARCTIC-SNOW” program, the ANR “EAIIST” project and the ADELISE “CNRS-LEFE” program. The deployment of this instrument in the field was made possible by the logistic support from the “NIVO2” and ADELISE “IPEV” programs. We thank the two reviewers for their useful comments which greatly improved the article.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; Antarctic; Dumont d'Urville; Dumont-d'Urville; Antarc*
• Online Access: https://hal.archives-ouvertes.fr/hal-03218431; https://hal.archives-ouvertes.fr/hal-03218431/document; https://hal.archives-ouvertes.fr/hal-03218431/file/amt-14-2907-2021.pdf; https://doi.org/10.5194/amt-14-2907-2021

International audience Obtaining precise continuous measurements of water vapor isotopic composition in dry places (polar or high-altitude regions) is an important challenge. The current limitation is the strong influence of humidity on the measured water isotopic composition by laser spectroscopy instruments for low humidity levels (below 3000 ppmv). This problem is addressed by determining the relationships between humidity and measured δ18O and δD of known water standards. Here, we present the development of a robust field instrument able to generate water vapor, down to 70 ppmv, at very stable humidity levels (average 1σ lower than 10 ppmv). This instrument, operated by a Raspberry interface, can be coupled to a commercial laser spectroscopy instrument. We checked the stability of the system as well as its accuracy when expressing the measured isotopic composition of water vapor on the VSMOW-SLAP (Vienna Standard Mean OceanWater-Standard Light Antarctic Precipitation) scale. It proved to be highly stable during autonomous operation over more than 1 year at the East Antarctic Concordia and Dumont d'Urville stations.