A 40-year record of Northern Hemisphere atmospheric carbon monoxide concentration and isotope ratios from the firn at Greenland Summit.

Wednesday, 17 December 2014
Philip Place Jr1, Vasilii V Petrenko1, Isaac Vimont2, Christo Buizert3, Patricia M Lang4, Jon Edwards3, Christina M Harth5, Benjamin Hmiel1, John E Mak6, Paul C Novelli4, Edward Brook3, Ray F Weiss5, Bruce H Vaughn2 and James W C White2, (1)University of Rochester, Department of Earth and Environmental Sciences, Rochester, NY, United States, (2)Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO, United States, (3)Oregon State University, College of Earth, Ocean, and Atmospheric Sciences, Corvallis, OR, United States, (4)National Oceanic and Atmospheric Administration, Global Monitoring Division, Earth System Research Laboratory, Boulder, CO, United States, (5)University of California San Diego, Scripps Institution of Oceanography, La Jolla, CA, United States, (6)SUNY Stony Brook, School of Marine and Atmospheric Sciences, Stony Brook, NY, United States
Carbon Monoxide (CO) is an important atmospheric trace gas that affects the oxidative capacity of the atmosphere and contributes indirectly to climate forcing by being a major sink of tropospheric OH. A good understanding of the past atmospheric CO budget is therefore important for climate models attempting to characterize recent changes in the atmosphere. Previous work at NEEM, Greenland provided the first reconstructions of Arctic atmospheric history of CO concentration and stable isotope ratios (δC18O and δ13CO) from firn air, dating to the 1950s. In this new study, firn air was sampled from eighteen depth levels through the firn column at Summit, Greenland (in May 2013), yielding a second, independent record of Arctic CO concentration and isotopic ratios. Carbon monoxide stable isotope ratios were analyzed on replicate samples and using a newly developed system with improved precision allowing for a more robust reconstruction. The new CO concentration and stable isotope results overall confirm the earlier findings from NEEM, with a CO concentration peak around the 1970s and higher δC18O and δ13CO values associated with peak CO. Modeling and interpretation of the data are in progress.