A High-Resolution Continuous Flow Analysis System for Polar Ice Cores

In recent decades, the development of continuous flow analysis (CFA) technology for ice core analysis has enabled greater sample throughput and greater depth resolution compared with the classic discrete sampling technique. We developed the first Japanese CFA system at the National Institute of Polar Research (NIPR) in Tokyo. The system allows the continuous analysis of stable water isotopes and electrical conductivity, as well as the collection of discrete samples from both inner and outer parts of the core. This CFA system was designed to have sufficiently high temporal resolution to detect signals of abrupt climate change in deep polar ice cores. To test its performance, we used the system to analyze different climate intervals in ice drilled at the NEEM (North Greenland Eemian Ice Drilling) site, Greenland. The quality of our continuous measurement of stable water isotopes has been confirmed through a comparison with different datasets. Moreover, our system presents a better measurement efficiency to resolve the signal of electrical conductivity in the ice core sample than that obtained with a similar system developed by the University of Bern, Switzerland, during a field campaign at NEEM camp.