9:30 AM - 9:45 AM
[ACC37-03] A 60-year record of isotopic compositions of nitrate preserved in the high-accumulation dome ice core, South East Greenland
Keywords:stable isotope, nitrate
Isotopic compositions of NO3- reveal changes in the nitrogen source and its formation pathways, but ice core records for NO3- concentrations and its isotopic compositions are problematic because of post depositional loss of NO3- via photolysis. In this study, we analyzed isotopic compositions of NO3- preserved in the high-accumulation dome ice core, South East Greenland. South East Greenland has a dome whose elevation is higher than 3000 m a.s.l. with high accumulation rate (about 1 m yr-1) in water equivalent. High elevation and accumulation rate gives high-time resolution reconstruction of past environment, and provides negligible effect of the post depositional loss of nitrate (NO3-). In fact, the nitrogen isotopic compositions for NO3- are generally lower than those reported in Summit, Greenland, suggesting negligible effect of post depositional loss of NO3- in this site. In the presentation, we present changes in NO3- concentration and its isotopic composition through recent 60 years, and discuss the changes in the source and formation pathways of nitrate.