Distribution of N 2 O in the Baltic Sea during transition from anoxic to oxic conditions
Distribution of N 2 O in the Baltic Sea during transition from anoxic to oxic conditions
复制标题
波罗的海从缺氧到有氧条件过渡期间 N 2 O 的分布
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
D. Wallace
中科院分区：
文献类型：
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作者：
S. Walter;U. Breitenbach;H. Bange;G. Nausch;D. Wallace
抽象的。2003年1月，寒冷和富含氧气的北海水的大量流入结束了波罗的海中部部分地区持续的停滞期。为了研究北海水流入在一氧化二氮(N2O)产生中的作用，我们在巡航时测量了溶解氮和大气氮，哥特兰盆地东部已经进行了水的更新，而哥特兰盆地西部仍然没有受到流入的影响。深水更新表现在温度、盐度和氧气浓度的分布以及N2O浓度的分布上：基尔湾和博美拉尼亚湾的浅水站通风良好，整个水柱的N2O浓度接近平衡。相比之下，位于深盆地的站，如博恩霍尔姆和哥特兰深，表现出明显的层结，深水受到北海水的影响。北海水的流入导致环境条件的变化，特别是氧气(O2)浓度的增加或硫化氢(H2S)浓度的下降，从而影响了N2O的产生条件。不同盆地的N2O分布模式以及与氧和硝酸盐等参数的相关性不同。在含氧水体中，由于Δ、N2O和AOU呈正相关，其主要的生成途径似乎是硝化作用而不是反硝化作用。北海水对N2O的平流作用较小。粗略的预算显示，在流入后，就地产生的N2O显着过剩。然而，由于永久的盐跃层，可以假设产生的N2O不会到达大气。因此，水文方面是决定产生的N2O最终释放到大气中的决定性因素。
Abstract. In January 2003, a major inflow of cold and oxygen-rich North Sea Water terminated an ongoing stagnation period in parts of the central Baltic Sea. In order to investigate the role of North Sea Water inflow in the production of nitrous oxide (N2O), we measured dissolved and atmospheric N At the time of our cruise, water renewal had proceeded to the eastern Gotland Basin, whereas the western Gotland Basin was still unaffected by the inflow. The deep water renewal was detectable in the distributions of temperature, salinity, and oxygen concentrations as well as in the distribution of the N2O concentrations: Shallow stations in the Kiel Bight and Pomeranian Bight were well-ventilated with uniform N2O concentrations near equilibrium throughout the water column. In contrast, stations in the deep basins, such as the Bornholm and the Gotland Deep, showed a clear stratification with deep water affected by North Sea Water. Inflowing North Sea Water led to changed environmental conditions, especially enhanced oxygen (O2) or declining hydrogen sulphide (H2S) concentrations, thus, affecting the conditions for the production of N2O. Pattern of N2O profiles and correlations with parameters like oxygen and nitrate differed between the basins. Because of the positive correlation between ΔN2O and AOU in oxic waters the dominant production pathway seems to be nitrification rather than denitrification. Advection of N2O by North Sea Water was found to be of minor importance. A rough budget revealed a significant surplus of in situ produced N2O after the inflow. However, due to the permanent halocline, it can be assumed that the N2O produced does not reach the atmosphere. Hydrographic aspects therefore are decisive factors determining the final release of N2O produced to the atmosphere.