9510665 Thiemens The atmospheric carbon monoxide budget is poorly characterized at present. In particular, it appears that there are sources which are either underestimated or unrecognized. Carbon monoxide is a central species related to the oxidizing capacity of the lower atmosphere. New techniques for resolving the sources and transformation mechanisms of atmospheric carbon monoxide are needed. Recent measurements of the abundances of the stable isotopes 17O and 18O indicate anomalies in the isotopic composition of atmospheric carbon monoxide, which likely indicates a signature of atmospheric processes which alter the isotopic composition. Previous work on ozone, carbon dioxide, and nitrous oxide revealed the nature of the atmospheric processes causing such isotopic anomalies in these molecules. In this project, a collection apparatus will be constructed to measure the isotopic composition of carbon and oxygen in atmospheric carbon monoxide, with the goal of obtaining new information on its global atmospheric budget. Routine measurements will be initiated in conjunction with the ongoing isotopic analysis programs for carbon dioxide, nitrous oxide, and ozone, including measurements of the concentrations of all species. Future activities will include the analysis of samples taken by balloon and rocket instruments.
