Oxidation, Photooxidation and Photodecomposition of Dicarbonylic and Ketocarboxylic Ice Core Dopants

California Institute Of Technology, Pasadena CA

Investigators

Abstract

This project involves quantitative studies on the photochemistry of the carbonylic group as pertains to photodecomposition of organic contaminants in ice cores and is thereby aimed at accounting for excess carbon monoxide and carbon dioxide gas levels observed in deep ice cores. Such ambiguities may increase significantly uncertainties associated with using ice cores to study issues of importance to the relevance and representativeness of paleoclimate records. Specifically, the project will use a combination of spectroscopic techniques and chemical analyses to characterize a variety of selected ice dopants, and subsequently investigate their photochemical reactions and transformations under monochromatic light at wavelengths at and above the near-UV, and further measure gaseous formation rates in synthesized ice mixtures containing a laboratory surrogate mineral dust. This study should lead to a better understanding of photochemical processes occurring in deep ice cores and provide important data required for a scientific evaluation of the possible mechanisms of corruption of historical ice records. The fundamental nature of the research as it applies to our future understanding of the paleoclimate ice core record addresses broader scientific impacts upon geoclimate, and broader scientific community impacts are addressed through scholarship, community involvement, technology transfer and capacity-building by outreach, minority and underrepresented group involvement, as well as mentoring and research direction of young geoscientists.