摘要
在中国第22次南极科学考察期间,用Tedlar气袋采集了"雪龙号"考察船航线上海洋边界层大气样品,在室内分析了样品中CH4浓度及其分子的δ13C值,结果表明:在28.5°N^40°S区域,海洋边界层大气CH4浓度波动较大,峰值较多,平均值为(2.97±1.51)×10-6,明显高于全球大气CH4的平均浓度(约1.8×10-6),这主要与该区域的航迹靠近陆地,受人为源的影响有关;在40°S^69.17°S航迹,远离人类活动区,洋面大气CH4的浓度较稳定,平均浓度值为(1.92±0.14)×10-6,接近于目前全球大气CH4平均浓度.航线上CH4分子的δ13C的变化范围为:-37.49‰^-24.87‰,平均为-34.5±3.0‰.在28.5°N^40°S区域,边界层大气中CH4分子的δ13C值较高且波动较大,表明洋面大气的CH4浓度受到来自富13C的化石燃料、生物质燃烧等人为源的强烈影响;在40°S^69.17°S区域,δ13C值较稳定.海洋边界层大气的CH4浓度分布与大气温度也存在相关性.
During the 22nd Chinese Antarctic Research Expedition （CHINARE-22）, air samples in the marine boundary layer were collected as the research ship Xuelong from Shanghai to Antarctica using Tedlar gas bags. The methane （CH4） concentration and its δ^13C in these air samples were analyzed in the laboratory. In the latitudinal range of 28. 5°N-40°S, the CH4 concentrations in the marine atmosphere showed a strong fluctuation with an average of （2.97 ± 1.51） ×10^-6, evidently higher than the average level （about 1.8×10^-6） for CH4 in the global atmosphere, suggesting that anthropogenie sources have a great impact on marine atmospheric CH4 concentrations since the track of the ship was very close to the land. In the remote latitudinal areas of 40°S-69.17°S,the CH4 concentrations in the marine atmosphere were very stable with an average of （1.92 ± 0.14） ×10^-6（close to the global average of CH4 concentration）. The δ^13C of CH4 ranged from -37.49%0 to -24. 87‰ with an average of -34.5±3.0‰. In the latitudinal range of 28.5°N-40°S, the δ^13C of CH4 also showed higher values, suggesting that the major proportion of CH4 was from fossil fuel and biomass burning. In the range of 40°S-69.17°S, the δ^13Cof CH4 was very stable. A significant correlation exists between marine atmospheric CH4 concentration and air temperature.
出处
《中国科学技术大学学报》
CAS
CSCD
北大核心
2007年第8期1017-1021,1035,共6页
JUSTC
基金
国家自然科学基金(40406001
40676005)资助
关键词
CH4浓度
碳同位素
海洋边界层大气
南极
空间分布
methane concentratiom carbon isotope
the marine boundary layer
Antarctica
spatial distribution
