MRI: Track 3 Acquisition of Helium Recovery Equipment - Closed-cycle Cryotraps for Polar Ice Core Trace Gas Analysis

University Of California-Irvine, Irvine CA

Investigators

Abstract

The air trapped in polar ice cores is the most accurate source of information about the variability in atmospheric composition. Measurements on polar ice cores inform us about how trace gases influence and respond to climate change on centennial and millennial time scales. The polar ice archive includes a wide range of climate-active trace gases (sulfur-containing gases, hydrocarbons, and halogenated compounds) that reflect emissions from oceanic biota and terrestrial ecosystems. The UCI laboratory has developed analytical techniques to extract and analyze such ultra-trace gases from polar archives, allowing researchers to reconstruct their atmospheric histories and understand how they are influenced by climate and human activities. Ongoing and planned projects require the analysis of large numbers of samples from Antarctic and Greenland ice cores. The implementation of closed-cycle cryotraps will ensure the ability to continue this research while conserving helium used in the analytical process. The analysis of air trapped in polar ice cores requires the extraction and manipulation of small air samples under ultra-clean conditions. In the UCI ice core laboratory this is currently done using liquid helium, a commodity subject to fluctuating supply and rapidly increasing costs. This project requests funds to purchase and install new closed-cycle cryogenic cold trap systems, eliminating the need for liquid helium. Installation of the closed-cycle cryotraps will ensure operational continuity and reduce long-term operating costs of the UCI ice core laboratory. The new cold cryotraps will be installed on vacuum lines used for the wet (melting) and dry (shredding) extraction of air from ice core samples for low-level trace gas analysis.The proposed instrumentation will support graduate and undergraduate student training. The ice core laboratory is actively involved in outreach activities both on campus and in local minority K-12 school districts. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.