Application of the Isotopes of Carbon Monoxide as Tracers of Current OH Trends and Preindustrial CO Chemistry

A comparison of very recent model simulations compared to observations indicates there is a recent, substantial change in the presence of the atmospheric tracer 14CO in the high latitude Northern Hemisphere. Such changes may well be a reflection of variations in the presence of atmospheric OH and therefore the atmospheric oxidation potential. In this project, researchers at the State University of New York at Stony Brook will measure 14CO at an established site (Westmann Islands, Iceland) and compare with model simulations to test our understanding of the atmospheric oxidation potential. Because 14CO is a cosmogenically produced molecule that reacts almost exclusively with OH, the loss rate can be calculated if the inventory is measured, since the production rate is now well constrained. As a result of efforts by the international modeling community, model simulations of 14CO have improved dramatically with the use of existing 14CO data. Assessing the atmospheric oxidation potential has recently been highlighted as an important research area (Lelieveld et al., 2006; 7th IGAC Conference, 2002: Hot Topic: Stability of Global OH and Detection of OH Trends). The research team will compare their NH data with data from the Southern Hemisphere as well, since sampling sites in the middle and high latitude Southern Hemisphere will be operated, independently but concurrently, by the National Institute for Water and Atmospheres, Crown Research Institute, New Zealand. The research team will also investigate the relative contribution from biomass burning to the CO budget of the Southern Hemisphere during preindustrial times. This will be done by measuring the abundance of the stable C and O isotopes of CO from firn air samples. This project will feature significant international and educational broader impacts. The scope of the research will be fundamentally international in terms of both scientific scope and scientific collaborations. Model development will be spearheaded by Prof. Maarten Krol (Utrecht University, the Netherlands), Dr. Patrick Jöckel (Max Planck Institute for Chemistry, Mainz, Germany), and Dr. Louisa Emmons (NCAR). Extraction of air from ice samples will take place at the Laboratory for Glaciology and Geophysics, National Scientific Research Center (CNRS), Grenoble, France, in collaboration with Dr. Jerome Chappellaz; and samples collected from the Southern Hemisphere, to be directly compared with our work in the NH, will be carried out by Dr. David Lowe?s research group at the National Institute for Water and Atmosphere, Crown Research Institute, Wellington, New Zealand. Collaborations such as these reflect the level of interest in this work by the international community. Because of its relatively high level of enrollment of minority students, SUNY Stony Brook is an excellent recruiting campus for identifying and nurturing underrepresented groups in the atmospheric sciences. The principal investigator plans to recruit and promote qualified, underrepresented minority students into the earth sciences. Undergraduate participation will be encouraged.