摘要
During the 22nd Chinese Antarctic Research Expedition (CHINARE-22), the atmospheric gas samples above the oceanic surface and near the surface were collected on the track for the scientific ship "Xuelong" and on Millor Peninsula of eastern Antarctica, respectively, using the Tedlar gas bags. Every day the sampling times were 10:00 and 22:00 (local time), respectively. In the laboratory, high-precision measurement of the isotopic compositions for N2O in these gas samples was conducted using Thermo Finnigan MAT-253 Isotopic Mass Spectrometer with a fully automated interface for the pre-GC concen-tration (PreCon) of trace gases. The temporal and spatial variations of δ 15N and δ 18O in atmospheric N2O were analyzed. The mean δ 15N and δ 18O-N2O values above the oceanic surface were (7.21±0.50)‰ and (44.52±0.52)‰, respectively. From 30°N to Antarctica, the δ 15N (6.05‰―7.88‰) linearly increased with the rate of about 0.01‰ with the latitude while the δ 18O (43.05‰―48.78‰) showed a large fluctua-tion. The δ 15N negatively correlated with air temperature and N2O concentration, and slightly positively correlated with δ 18O. The summertime variations of δ 15N and δ 18O-N2O appeared the same trend on Millor Peninsula of eastern Antarctica. They significantly positively correlated with each other and negatively with N2O concentration. The δ 15N and δ 18O-N2O at different sites averaged (7.42±0.35)‰ and (44.69±0.49)‰, respectively, slightly higher than those above the oceanic surface, significantly higher than those of atmospheric N2O in the low-latitude regions of Northern Hemisphere. The predominant factors affecting the spatial variations of δ 15N and δ 18O values were also discussed. The isotopic data given in this study can help to investigate the global and regional N2O budgets.
During the 22nd Chinese Antarctic Research Expedition (CHINARE-22), the atmospheric gas samples above the oceanic surface and near the surface were collected on the track for the scientific ship "Xuelong" and on Millor Peninsula of eastern Antarctica, respectively, using the Tedlar gas bags. Every day the sampling times were 10:00 and 22:00 (local time), respectively. In the laboratory, high-precision measurement of the isotopic compositions for N_2O in these gas samples was conducted using Thermo Finnigan MAT-253 Isotopic Mass Spectrometer with a fully automated interface for the pre-GC concen- tration (PreCon) of trace gases. The temporal and spatial variations of δ^(15)N and δ^(18)O in atmospheric N_2O were analyzed. The mean δ 15N and δ^(18)O-N_2O values above the oceanic surface were (7.21±0.50)‰ and (44.52±0.52)‰, respectively. From 30°N to Antarctica, the δ^(15)N (6.05‰―7.88‰) linearly increased with the rate of about 0.01‰ with the latitude while the δ^(18)O (43.05‰―48.78‰) showed a large fluctua- tion. The δ^(15)N negatively correlated with air temperature and N2O concentration, and slightly positively correlated with δ^(18)O. The summertime variations of δ^(15)N and δ^(18)O-N_2O appeared the same trend on Millor Peninsula of eastern Antarctica. They significantly positively correlated with each other and negatively with N_2O concentration. The δ^(15)N and δ^(18)O-N_2O at different sites averaged (7.42±0.35)‰ and (44.69±0.49)‰, respectively, slightly higher than those above the oceanic surface, significantly higher than those of atmospheric N_2O in the low-latitude regions of Northern Hemisphere. The predominant factors affecting the spatial variations of δ^(15)N and δ^(18)O values were also discussed. The isotopic data given in this study can help to investigate the global and regional N_2O budgets.
作者
ZHU RenBin1, LIU YaShu1, XU Hua2, MA Jing2 & SUN LiGuang1 1 Institute of Polar Environment, University of Science and Technology of China, Hefei 230026, China
2 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210091, China
基金
the National Natural Science Foundation of China (Grant Nos40676005 and 40406001)
