Past climate changes and their causes and in particular climate conditions during past warmer climates than today represent important benchmarks for climate models which are used for predictions of future warming due to increased atmospheric CO2 concentrations. Past climate conditions can be reconstructed using a variety of natural climate archives, however, polar ice cores represent the only direct archive of the past atmosphere and, as such, allow the unambiguous reconstruction of greenhouse gas concentrations back in time. In fact, everything we know about variations in greenhouse gas concentrations before the advent of direct atmospheric measurements in the second half of the 20th century comes from ice core research.
However, the use of the paleo atmospheric archive in polar ice cores is currently limited in terms of temporal coverage, resolution and sample availability in the bottom-most part of the Antarctic and Greenland ice sheets where extreme thinning of the ice by glacier flow occurs. The overarching goal of deepSLice is, therefore, to develop a new analytical method that overcomes these limitations, opening the window for high quality gas records, for example for a future Oldest Ice ice core from Antarctica covering the Mid Pleistocene Transition 0.9-1.5 million years ago.
Accordingly, deepSLice is developing
1) a Quantum Cascade Laser Absorption Spectrometer (QCLAS) to measure CO2, CH4 and N2O concentrations as well as the carbon isotopic signature of CO2 (δ13CO2) in small ice core samples from highly thinned ice.
2) a quantitative, contamination free, and non-fractionating extraction system for the air enclosed in such small ice samples using Continuous Sublimation Extraction (CSE).
