Nitrate concentration and isotopes in DA2005 core from Dome A, East Antarctica

DA2005 core was recovered at a site about 300 m from the summit of Dome A, East Antarctica in 2004/2005. The total length of the core is 109.91m. The top 100.42m of the DA2005 core was analyzed in the Ice Core and Environment Chemistry Laboratory at South Dakota State University, USA for nitrate concentrations. Tubes 1 - 4 (0-1.765 m) were analyzed with discrete sampling followed by concentration determination by ion chromatograph. All other tubes were analyzed by CFA-IC (melter-based continuous flow analysis with ion chromatography detection). The top 100.42 m of the core corresponds to the last 2840years, from 840 BC to AD 1998. The top 8.98-86.66 m of the DA2005 core, covering the time period from 352 BC to AD 1838,were analyzed for nitrate isotopes in the stable isotope laboratory at University of Washington. Nitrate concentrations are shown in annual mean values. Negative year means BC.