Author/Authors :
iizuka, yoshinori hokkaido university - institute of low temperature science, Sapporo, Japan , uemura, ryu university of the ryukyus - faculty of science - department of chemistry, biology, and marine science, Nishihara, Japan , fujita, koji nagoya university - graduate school of environmental studies, Nagoya, Japan , hattori, shohei tokyo institute of technology - school of materials and chemical technology - department of chemical science and engineering, Yokohama, Japan , seki, osamu hokkaido university - institute of low temperature science, Sapporo, Japan , miyamoto, chihiro university of tokyo - graduate school of science - department of earth and planetary science, Tokyo, Japan , suzuki, toshitaka yamagata university - faculty of science - department of earth and environmental sciences, Yamagata, japan , yoshida, naohiro tokyo institute of technology - earth-life science institute, Yokohama, japan , yoshida, naohiro tokyo institute of technology - school of materials and chemical technology - epartment of chemical science and engineering, Yokohama, Japan , motoyama, hideaki national institute of polar research, Tokyo, Japan , matoba, sumito hokkaido university - institute of low temperature science, Sapporo, Japan
Abstract :
The Southeastern Greenland Dome (SE-Dome) has both a high elevation and a high accumulation rate (1.01 m we yr-1), which are suitable properties for reconstructing past environmental changes with a high time resolution. For this study, we measured the major ion fluxes in a 90 m ice core drilled from the SE-Dome region in 2015 and present the records of annual ion fluxes from 1957 to 2014. From 1970 to 2010, the trend of nonsea-salt (nss) SO4 2- flux decreases, whereas that for NH4 + increases,tracking well with the anthropogenic SOx and NH3 emissions mainly from North America. The result suggests that these fluxes reflect histories of the anthropogenic SOx and NH3 emissions. In contrast, the decadal trendo f NO3-flux differs from the decreasing trend of anthropogenic NOx emissions. Although the cause of this discrepancy remains unclear, it may be related to changes in particle formation processes and chemical scavenging rates caused by an increase in sea salt and dust and/or a decrease in nssSO4 2-. We also find a high average NO3- flux (1.13 mmol m-2 yr-1) in the ice core, which suggests a negligible effect from postdepositional NO3- loss. Thus, the SE-Dome region is an excellent location for reconstructing nitrate fluxes. Over a decadal time scale, our NO3- flux record is similar to those from other ice cores in Greenland high-elevation sites, suggesting that NO3- concentration records from these ice cores are reliable.
