Shifts in Atmospheric Oxidation Capacity Following Natural and Anthropogenic Climate Change

The stable isotopes of nitrogen and oxygen of the Ross Ice Drainage System (RIDS) ice-core nitrate were measured in approximately 2-3 year time resolution using a Delta V Isotope Ratio Mass Spectrometer (IRMS). The nitrogen isotope variation (δ15N) and the mass-independent fractionation of oxygen (Δ17O = δ17O - 0.52*δ18O) yield a detailed picture of the changes in the global nitrogen cycling and the shift in the oxidation capacity of the atmosphere in response to natural and anthropogenic induced climate change. This is one of the few studies on stable isotopes of ice-core nitrate for time periods prior to the 1800's and will increase our understanding of the oxidation feedbacks of the atmosphere in response to natural and anthropogenic emissions in the Southern Hemisphere.