Invited Article: SUBGLACIOR: An optical analyzer embedded in an Antarctic ice probe for exploring the past climate

• Published in: Review of Scientific Instruments
• Main Authors: Grilli, R., Marrocco, N., Desbois, T., Guillerm, C., Triest, J., Kerstel, E., Romanini, D.
• Other Authors: European Research Council, Agence Nationale de la Recherche
• Format: Article in Journal/Newspaper
• Language: English
• Published: AIP Publishing 2014
• Subjects: Antarctic; Antarc*; ice core; Ice Sheet
• Online Access: http://dx.doi.org/10.1063/1.4901018; https://pubs.aip.org/aip/rsi/article-pdf/doi/10.1063/1.4901018/13414894/111301_1_online.pdf

This article describes the advances made in the development of a specific optical spectrometer based on the Optical Feedback-Cavity Enhanced Absorption Spectroscopy technique for exploring past climate by probing the original composition of the atmosphere stored in the ice sheet of a glacier. Based on significant technological progresses and unconventional approaches, SUBGLACIOR will be a revolutionary tool for ice-core research: the optical spectrometer, directly embedded in the drilling probe, will provide in situ real-time measurements of deuterium isotopic variations (δ2H ) and CH4 concentrations down to 3500 m of ice depth within a single Antarctic season. The instrument will provide simultaneous and real-time vertical profiles of these two key climate signatures in order to evaluate if a target site can offer ice cores as old as 1.5 million years by providing direct insight into past temperatures and climate cycles. The spectrometer has a noise equivalent absorption coefficient of 2.8 × 10−10 cm−1 Hz−1/2, corresponding to a detection limit of 0.2 ppbv for CH4 and a precision of 0.2‰ on the δ2H of H2O within 1 min acquisition time.