| 摘要: |
| 根据渤海断面1978～2014年历年8月温度、盐度和溶解氧观测资料，采用旋转经验正交函数（REOF）、最大熵谱和延迟相关等方法，研究了渤海夏季断面溶解氧含量和表观耗氧量年际变化时空模态.溶解氧含量主要存在4种时空模态：第一模态空间分量主权重在10 m以深水体；时间分量均为显著线性低氧趋势周期年际变化和10a尺度跃变.第二、四模态空间分量主权重在5 m以浅水体及断面南端底层；时间分量均为显著线性高氧趋势周期年际变化和10a尺度跃变.第三模态空间分量主权重在10 m附近；时间分量为准平衡态周期变化和10a尺度跃变.表观耗氧量主要有4种时空模态：第一、二模态空间分量主权重在中层及底层；时间分量均为显著线性贫氧趋势周期变化和10a尺度跃变.第三、四模态空间分量主权重在5 m以浅水体及断面南端底层；时间分量均为显著线性富氧趋势周期变化和10a尺度跃变.生物活性组分耗氧与海流输送减氧过程是夏季溶解氧、表观耗氧量模态显著线性低氧、贫氧趋势年际变化主要影响因素，饱和溶解氧强增氧、生物活性组分光合作用生氧和海流输送增氧过程是夏季溶解氧、表观耗氧量模态显著线性高氧、富氧趋势年际变化主要影响因素.渤海夏季深层水体中生物耗氧作用大于浅层水体中生物生氧作用，20 m以深水体中显著线性低氧、贫氧趋势快于20 m以浅水体的显著高氧、富氧趋势.生物活性组分氧化与光合作用是渤海夏季年际平均溶解氧含量、表观耗氧量分布以及溶解氧含量、表观耗氧量年际时空变化的主要影响因素，温度、盐度不是主要影响因素. |
| 关键词: 物理海洋学 溶解氧 表观耗氧量 年际变化 时空模态 渤海 |
| DOI：10.3969/J.ISSN.2095-4972.2016.02.014 |
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| 基金项目:山东省海洋生态环境与防灾减灾重点实验室资助项目（2011011）；国家海洋公益性科研专项资助项目（201205010） |
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| Spatio-temporal mode for inter-annual change of dissolved oxygen and apparent oxygen utilization in summer Bohai Sea |
| SHI Qiang |
| (Shandong Province Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation，Qingdao 266033，China;North China Sea Environmental Monitoring Center，SOA， Qingdao 266033，China;Key Laboratory of Marine Spill Oil Identification and Damage Assessment Technology，SOA， Qingdao 266033，China) |
| Abstract: |
| Based on the temperature， salinity and dissolved oxygen data of August from 1978 to 2014， The spatio-temporal modes on the inter-annual variation of dissolved oxygen content and apparent oxygen utilization （AOU） in summer in the Bohai Sea section were studied with methods of Rotated Empirical Orthogonal Function （REOF）， maximum entropy spectrum and the delay correlation analysis. The results show that the inter-annual variation of dissolved oxygen content is divided into four major types of spatio-temporal modes. The first mode， the major weight of the spatial component lies at more than 10 meters below the sea surface， and the temporal component denotes a remarkable linear inter-annual variation of low oxygen trend and decadal scale jumps. The second and the fourth modes， the major weight of spatial components locate at water layers shallower than 5 meters and the sea bottom of the southern tip， and the temporal components show an evidently linear inter-annual variation of high oxygen trend and decadal scale jumps. The third mode， the major weight of spatial component lies at about 10 meters below the sea surface， and the temporal component denotes a quasi-equilibrium state inter-annual variation and decadal scale jumps. The inter-annual variation of apparent oxygen utilization is also divided into four major types of spatio-temporal modes. The first and second modes， the major weight of the spatial components lies at the middle and bottom layer below the sea surface， and the temporal components denote a remarkable linear inter-annual variation of poor oxygen trend and decadal scale jumps. The third and fourth modes， the major weight of the spatial components locates at less than 5 meters and the bottom of the southern tip below the water， and the temporal components show an evidently linear inter-annual variation of rich oxygen trend and decadal scale jumps．Oxygen consumption of biological active components and oxygen reduction process of sea current transport are the dominant components for explaining the remarkable linear inter-annual variation of low and poor oxygen trend in dissolved oxygen and apparent oxygen utilization in summer. Likewise， Oxygen generation of biological photosynthesis， oxygen increase process of saturated dissolved oxygen and sea current transport are significant reflecting evidently linear inter-annual variation of high and rich oxygen trend in dissolved oxygen and apparent oxygen utilization in summer. The effect of oxygen consumption in deep water is greater than oxygen generation in shallow water in summer in the Bohai Sea， and linear inter-annual variation of low and poor oxygen trend at layers deeper than 20 meters are faster than those at layers shallower 20 meters. So oxidation and photosynthesis of biologically active components， rather than temperature and salinity， are the dominant components reflecting the annual mean distribution and inter-annual variation of dissolved oxygen content and apparent oxygen utilization |
| Key words: physical oceanography dissolved oxygen content apparent oxygen utilization spatio-temporal mode Inter-annual variation Bohai Sea |
