Laser-induced sublimation extraction for centimeter-resolution multi-species greenhouse gas analysis on ice cores

Abstract. Precision, accuracy, and temporal resolution are key to making full use of atmospheric trace gas records in ice cores. These aspects will become especially crucial for cores that aim extend the core record last 1.5 Myr, i.e., across Mid-Pleistocene Transition (as currently drilled within European project Beyond EPICA – Oldest Ice Core (BE-OIC)). The from this period is expected be close bedrock and, due glacier flow, extremely thinned with 15 000 years climate history contained only 1 m ice. Accordingly, a century-scale resolution, sample vertical extent must reduced few centimeters containing about 1–2 mL air STP. We present novel combined system extraction simultaneous measurement CO2, CH4, N2O concentrations, as well δ13CO2, which achieves cm (3.5×3.5 cross section) precisions 0.4 ppm, 3 ppb, 0.04 ‰, respectively, sublimation tests standard over gas-free This accomplished by employing directional continuous laser-induced followed analysis quantum cascade laser absorption spectrometer (QCLAS). Besides low volume requirements capabilities, described method holds additional advantages previous methods, including immunity highly specific QCLAS drilling fluid contamination non-destructive nature spectroscopic analysis. was extensively tested sublimating introduction determine accuracy characterize potential artifacts. Moreover, Antarctic samples were measured confirm performance, covering range variability Pleistocene highlighting capabilities critical its application BE-OIC.