象山湾大气中CH_(4)和CO_(2)时空分布及其同位素组成特征  

Spatial and temporal variation and isotopic composition of CH_(4)and CO_(2)in Xiangshan Bay

作　　者：李雪[1,2,3] 段晓勇[1,3] 印萍 高飞[1,3] 曹珂[1,3] 田元 李梅娜 刘晓凤 吕胜华 LI Xue;DUAN Xiao-yong;YIN Ping;GAO Fei;CAO Ke;TIAN Yuan;LI Mei-na;LIU Xiao-feng;LüSheng-hua(Qingdao Institute of Marine Geology,China Geological Survey,Qingdao 266237,China;China University of Geosciences(Wuhan),Wuhan 430074,China;Zhoushan Marine Geological Disaster Field Scientific Observation and Research Station,China Geological Survey,Qingdao 266237,China;Qingdao Guoshi Technology Group Limited Company,Qingdao 266237,China)

机构地区：[1]中国地质调查局青岛海洋地质研究所,山东青岛266237 [2]中国地质大学(武汉),湖北武汉430074 [3]中国地质调查局,舟山海洋地质灾害野外科学观测研究站,山东青岛266237 [4]青岛国实科技集团有限公司,山东青岛266237

出　　处：《中国环境科学》2023年第10期5162-5169,共8页China Environmental Science

基　　金：国家重点科技发展计划(2022YFE0209300);国家自然科学基金资助项目(42176091);国家地质调查项目(DD20221775)。

摘　　要：海湾区域的温室气体排放对于全球变暖具有重要影响,因此本研究选取中国东部典型海湾-象山湾作为研究对象,通过对CH_(4)和CO_(2)的浓度与同位素的时空变化特征分析来揭示海岸带对全球气候变化的影响.象山湾海域低层大气中CH_(4)浓度变化范围为(1.72~2.17)×10^(-6),平均浓度为1.82×10^(-6);δ^(13)CCH_(4)的变化范围为-60.69‰~-41.10‰,平均值为-50.261‰;CO_(2)浓度变化范围为(410.3~640.3)×10^(-6),平均浓度为433.294×10^(-6);δ^(13)CCO_(2)的变化范围为-16.79‰~-2.33‰,平均值为-6.83‰.CH_(4)含量整体上呈湾内大于湾外、从陆地向海方向逐渐减少的趋势,表明近浅海区域是大气甲烷的源;而CO_(2)含量变化湾内整体呈现偏低的趋势,证明是CO_(2)的汇.CH_(4)和CO_(2)的浓度变化受人为因素影响较大,建筑用地和林地、耕地区域温室气体明显偏高;相反,光滩和水产养殖区域温室气体的浓度较低.同时CH_(4)和CO_(2)的浓度昼夜变化基本一致,均呈现夜间大于白天的趋势,且同位素组成与其浓度呈负相关.CH_(4)和CO_(2)的浓度昼夜变化受温度、潮汐作用、大气源汇强度等影响显著.Understanding the greenhouse gas emissions in the global Gulf region is of great significance for coping with global warming.Therefore,the Xiangshan Bay,a typical gulf,was selected to reveal the impact of coastal zone on global climate change,through analyzing the concentration changes of CH_(4)and CO_(2)and their relationship with meteorological elements in the bay.The data showed that the CH_(4)concentrations in Xiangshan Bay area ranged from 1.72×10^(-6)to 2.17×10^(-6),with an average concentration of 1.82×10^(-6).Theδ^(13)CCH_(4)values range from-60.69‰to-41.10‰,with an average value of-50.261‰.The concentrations of CO_(2)range from 410.3×10^(-6)to 640.883×10^(-6),with an average concentration of 433.294×10^(-6).Theδ^(13)CCO_(2)values range from-16.79‰to-2.33‰,with an average value of-6.83‰.On the whole,the content of CH_(4)in the bay was greater than that outside the bay,and gradually decreased from land to sea,indicating that the near shallow sea area was the source of atmospheric methane.The overall trend of CO_(2)content variation in the bay was low,which indicates that it is the sink of CO_(2).Combined with land use types,the changes of CH_(4)and CO_(2)concentrations were greatly affected by anthropic factors,and greenhouse gases were significantly higher in building land,forest land and cultivated land.In contrast,the concentrations of greenhouse gases were lower in the plain and aquaculture areas.At the same time,the diurnal variation of CH_(4)and CO_(2)concentrations was basically the same,showing a tendency of greater during daytime than that of at night,and the isotopic composition was negatively correlated with their concentrations.In terms of time distribution,the concentration of CH_(4)and CO_(2)is significantly affected by temperature,humidity,wind speed,tidal action,the strength of large air source and sink,and the pressure difference at the water-air interface.

关 键 词：象山湾 甲烷 二氧化碳 浓度 同位素 

分 类 号：X51[环境科学与工程—环境工程]