Spectroscopic study for CO2 measurements from a spatial DIAL system

CO₂ is the main gas from anthropogenic origin contributing to the greenhouse effect of the Earth’s atmosphere. Several satellites, based on passive remote sensing IR optical techniques, are already measuring greenhouse gases (OCO-2, GOSAT) or are planned in the coming years (MicroCarb). The possibility of using an active lidar technique to monitor atmospheric CO₂ is currently studied at Laboratoire de Météorologie Dynamique (LMD ; Palaiseau). This technique would allow improving by a factor of three precision and accuracy on the CO₂ total column. This depends, for a part of it, on the availability of precise and accurate spectroscopic data.
The goal of the proposed internship at LIPhy is to complete the previous spectroscopic studies dedicated to ¹²CO₂, by recording high quality spectra of water vapor and ¹³CO₂ in the selected spectral window around 2051 nm. These latter two species are the main interfering species and have to be well characterized to avoid possible biases. For that, the student will use a state-of-the-art experiment based on a highly sensitive cavity ring down spectrometer referenced to a frequency-comb. The student will also analyze the recorded water vapor and ¹³CO₂ spectra with different line profiles to provide the spectroscopic parameters (position, intensity, pressure broadening coefficient...) for the different absorption lines.
The candidate has to send by e-mail a CV and a cover letter to D. Mondelain (didier.mondelain univ-grenoble-alpes.fr)

References
H. Tran, S. Vasilchenko, D. Mondelain, S. Kassi, A. Campargue, Accurate absorption spectroscopy of water vapour near 1.64 µm in support of the MEthane Remote LIdar missioN (MERLIN) J. Quant. Spectrosc. Radiat. Transfer doi.org/10.1016/j.jqsrt.2019.06.027
P. Cermák, S. Vasilchenko, D. Mondelain, S. Kassi, A. Campargue, Chemical Physics Letters 668 (2017) 90–94