摘要
科学评估陆架边缘海溶解甲烷(CH_(4))的分布及海-气交换通量对于认识陆架边缘海CH_(4)的释放对大气CH_(4)的区域性贡献具有重要意义。基于2022年8月的现场调查数据和资料,研究北黄海北部海水溶解CH_(4)的分布、海-气交换通量及影响因素。结果表明:研究海域溶解CH_(4)浓度为4.0~63.3 nmol/L,饱和度为168%~2 360%,高值区位于鸭绿江口附近海域,随着离岸距离的增加表层海水溶解CH_(4)浓度迅速降低。鸭绿江等陆源冲淡水的输入耦合海水及沉积物有机质的降解致使近岸海域海水CH_(4)升高;陆源冲淡水与海水混合过程中海水CH_(4)的氧化消耗也是控制CH_(4)浓度和分布不容忽视的重要过程。离岸海域海水及沉积物有机质厌氧降解耦合黄海冷水团的作用使得底层海水溶解CH_(4)浓度高于表层海水。研究海域海-气CH_(4)交换通量为18.4~578.8μmol/(m^(2)·d),是大气CH_(4)的源;鸭绿江口附近海域海-气CH_(4)交换通量高于离岸海域。由此可见,受陆源冲淡水输入的影响研究海域溶解CH_(4)浓度和海-气交换通量具有显著的区域性差异,且变幅高于世界其他海域;加强河口以及近海调查研究对于准确评估陆架边缘海CH_(4)的排放,明确CH_(4)排放源项的构成及制定CH_(4)减排的有效措施至关重要。
Scientific assessment of the distribution and sea-air fluxes of dissolved methane(CH_(4))in the marginal sea is important for understanding the regional contribution of CH_(4) emission to the atmosphere.The distribution,influencing factors and sea-air fluxes of CH_(4) in the northern of the North Yellow Sea were studied based on a survey in August 2022.The results showed that the dissolved CH_(4) concentrations range were from 4.0 nmol/L to 63.3 nmol/L with saturations from 168%to 2360%in the study area.High CH_(4) concentrations were observed in Yalu River estuary,and the dissolved CH_(4) concentrations in surface seawater decreased rapidly as the estuary extends to the sea,while the input of diluted water from terrestrial sources such as the Yalu River coupled with the degradation of seawater and sediment organic matter leaded to an increase in CH_(4) in inshore area.The oxidative consumption of CH_(4) in seawater mixing with the terrestrial diluted water was also an important process that could not be ignored in controlling CH_(4) concentration and distribution.The action of North Yellow Sea Cold Water Mass coupled with anaerobic degradation of sediment organic matter resulted in relatively high dissolved CH_(4) concentrations in bottom seawater than that in surface seawater in the offshore area.In the study area the sea-air CH_(4) fluxes were from 18.4μmol/(m^(2)·d)to 578.8μmol/(m^(2)·d),being the source of atmospheric CH_(4) and it was significantly higher in the inshore area than that of the offshore area.Therefore,the dissolved CH_(4) concentrations and sea-air fluxes in this area had significant differences due to the inputs of diluted water,and the variation amplitude was higher than that of other sea area in the world.It is crucial to strengthen the investigation and research in coastal areas such as estuary to accurately assess the CH_(4) emissions and emission source composition to formulate effective CH_(4) reduction measures.
作者
徐雪梅
王明丽
何宗财
韩建波
邢庆会
王心怡
陈虹
XU Xuemei;WANG Mingli;HE Zongcai;HAN Jianbo;XING Qinghui;WANG Xinyi;CHEN Hong(National Marine Environmental Monitoring Center,Dalian 116023,China;Shandong Provincial Qingdao Eco-environment Monitoring Center,Qingdao 266003,China;College of Environment Science and Engineering,Dalian Maritime University,Dalian 116026,China)
出处
《海洋科学进展》
CAS
CSCD
北大核心
2024年第4期782-793,共12页
Advances in Marine Science
基金
国家自然科学基金项目(41876128和41206060)
大连市海洋碳汇重点实验室项目。
关键词
北黄海
溶解甲烷
海-气CH_(4)交换通量
冲淡水输入
有机质厌氧降解
the North Yellow Sea
dissolved methane
air-sea CH_(4) flux
inputs of diluted water
anaerobic degradation of organic matter
作者简介
徐雪梅(1982-),女,高级工程师,博士,主要从事海洋碳循环观测评估方面研究.E-mail:xmxu@nmemc.org.cn;通信作者:王明丽(1981-),女,高级工程师,硕士,主要从事环境监测评估方面研究.E-mail:wangml2996@163.com。
