Distributions of Nitrous Oxide and its Influence Factors in the Bering Sea, Western Arctic Ocean and Nordic Sea

氧化亚氮（Nitrousoxide，N2O）是大气中重要的温室气体，也是破坏臭氧层的化学物质之一，海洋是大气中N2O重要源。随着气候变暖效应的增强，海洋系统发生一系列变化，如：海表温度上升、海冰减少、海平面上升以及海洋酸化等现象。北冰洋是地球系统的重要组成部分，对气候变化的响应和反馈具有放大作用，在北极海域开展N2O温室气体的研究，可揭示北冰洋在全球N2O循环过程中扮演的重要角色。本研究于中国第五次北极科学考察期间，利用静态顶空分析方法，首次对白令海、西北冰洋及北欧海N2O的分布特征及影响因素进行研究。主要研究结果如下： 1.研究海区表层海水N2O浓度范围为9.9-20.2nmolL-1，饱...Nitrous oxide is an important greenhouse and ozone-depleting gas. Ocean act as a net source to the atmosphere. Marine system subject to global change, suffer from surface water temperature change, shrink of sea-ice cover, and ocean acidification. Arctic Ocean is an important ocean, which is sensitive to the climate change. Research of N2O in the Arctic Ocean is a blind spot of global N2O study. Du...学位：理学博士院系专业：海洋与地球学院_海洋化学学号：2232012015344

Review on Researches of Nitrous Oxide in the Southern Ocean and Relative New Technologies

氧化亚氮(n2O)是大气最重要的温室气体之一,能在大气滞留120年,其增温潜势是CO2的310倍。工业革命以来,大气中n2O浓度已增加了20%,但海洋仍然是大气n2O重要的自然源,占总自然源的1/3左右。南大洋是全球海洋系统重要组成部分,具有独特的水文特征。模式研究表明其是大气n2O的重要源。然而,受制于恶劣的海况条件,南大洋航次观测数据至今十分稀少。简单综述了南大洋n2O研究的重要性、研究进展及现场观测技术和模型应用的结果及其存在的问题。强调稳定同位素方法的运用将为海洋n2O形成机制研究提供新的强有力手段,另外,研发高精度的走航观测技术也是今后n2O研究取得突破的必须努力方向。展望激光光谱技术的运用对南大洋n2O研究的突破以及海冰中n2O浓度测量技术的发展,将对评估海冰在形成和融化过程中可能存在的源汇提供直测证据。Nitrous oxide is an important greenhouse gas,which has a long lifetime of about 120 years and has a 310 times greenhouse effect than CO2.Since the industrial revolution,the atmospheric N2O concentration has increased significantly by 20%.Ocean is a net source,about 1 /3 of total oceanic souce.Southern Ocean is an important part of the global ocean system,has a unique hydrological characteristics.So far it is regarded as a significant natural source to the global N2O flux according to the model studies.However,the field work is very limit,due to the fierce in situ conditions.The importance of N2O reseaches of Southern Ocean,progresses of nitrous oxide researches,especially new technologies applied to underway N2O measurements in the Southern Ocean are reviewed.The advance of field,model studies and their problems or uncertainties that need to be resolved are also discussed.The using of stable isotope methods will provide powerful tools for marine N2O mechanism.Development of highprecision monitoring technology is generally the driving force of future research.Developing techniques of laser spectroscopy in marine N2O studies and measurment of N2O in sea ice will provide powerful tools to differeciate the N2O source sink characteristic,constrain their budget and formation mechanism in region such as Southern Ocean.中国极地科学战略青年基金项目“普里兹湾N2O分布特征及可能形成机制”(编号:20120310)资

Distribution of N_2O in the Jiulongjiang River Estuary and estimation of its air-sea flux during winter

氧化亚氮(n2O)因其强温室效应和潜在的臭氧破坏作用备受关注.大量研究显示河口区域,特别是人为氮源输入影响严重的区域是n2O的重要源区.随着氮肥施用量的快速增加,中国大陆河口区域对全球n2O收支势必有较大的贡献.本文研究了2009年冬季九龙江口表层水n2O浓度的分布特征及其影响因素,并评估了其海气通量.研究结果显示,冬季九龙江河口表层水体n2O浓度从盐度低至0.3时的81.7±1.7 nMOl/dM3下降至盐度为27.2时的14.1±0.2 nMOl/dM3,相应盐度下其饱和度分别为754%和138%;九龙江河口为大气n2O的强源区.与nO3-n、nO2-n、nH4-n等营养盐浓度的分布特征相比较可推测,2009年冬季n2O在九龙江河口的混合过程中呈不保守状态,部分n2O可能通过海气混合过程从水体迁移出.n2O的海气通量呈由高盐处向低盐处递增的趋势,变化范围在3--94μMOl/(M2.d)之间.N2O is considered as one of the most important greenhouse gases and also has the potential to deplete stratospheric ozone.Estuaries,especially those affected by human activity,are regarded as potential sources of atmospheric N2O.N2O in surface water was sampled at seven stations in the winter of 2009 along the south coast of the Jiulongjiang River Estuary,and a gas chromatograph was employed to analyze the concentration of N2O and the concentrations of DO and nutrients(NO3-N,NO2 N,NH4-N) were also measured.This work offers a snapshot of the N2O concentration and distribution characteristics for the Jiulongjiang River Estuary and its relationship with biogenic elements,and assesses the air-sea flux of N2O.The results show that the concentration of N2O in the Jiulongjiang River Estuary decreases from 81.7±1.7 nmol/dm3(754% saturation) at salinity of 0.3 to 14.1±0.2 nmol/dm3(138% saturation) at salinity of 27.2 in winter.Comparing with the distribution of nutrients,it is seen that N2O mixing is non-conservative,and air-sea exchange is a mechanism for the removal of N2O.The study area behaves as a significant N2O source.Air-sea flux has a progressive trend from a high-salinity area to a low-salinity area,ranging from 3 to 94 μmol/(m2·d).福建省科技计划青年人才资助项目(2007F3056