| 摘要: |
| 于2018年7月对长江口及其邻近海域水体中的海洋化学参数进行了3个连续站和5个大面站的调查，分析了该海区水体层化和潮汐作用对颗粒氮（PN）和颗粒磷（PP）的影响。结果表明，该海区PN浓度为0.75~27.42 μmol·L-1，平均值为5.39 μmol·L-1；PP浓度为0.07~2.05 μmol·L-1，平均值为0.37 μmol·L-1。PN和PP与悬浮颗粒物（TSP）均具有较好的相关性，表现出明显的同源性。层化现象和潮汐作用对二者的运移和分布有很大影响，层化不利于底层颗粒物的向上输运，使得PN和PP垂直分布出现明显分层现象，同时长江冲淡水与高盐水交汇形成的锋面，使大颗粒物质在锋面以西快速沉降，阻碍了颗粒物氮磷向外海的水平输送。潮汐是该海区PP、PN水平输送的主要动力来源之一，在潮汐作用下，长江冲淡水的运移及底层沉积物的再悬浮对水体中颗粒氮磷的周期性变化产生重要的影响，在上升流区底层及中层PN和PP浓度受沉积物再悬浮作用周期性增大。相关工作对分析河口海域化学成分的分布和水动力作用的相关性具有重要作用。 |
| 关键词: 长江口 颗粒氮磷 层化现象 潮汐作用 |
| DOI：10.11759/hykx20210319003 |
| 分类号:P734 |
| 基金项目:国家环境保护近岸海域生态环境重点实验室开放基金（202112）；自然资源部海洋生态环境科学与工程重点实验室开放基金（MESE-2019-06）；国家重点研发计划（2019YFC1407802） |
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| Effects of stratification and tides on the transport of particulate nitrogen and phosphorus near the Changjiang River Estuary in summer |
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GE Tian-tian1, WANG Xin-yang1,2, TAN Li-ju1, LI Tie1
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1.College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China;2.School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
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| Abstract: |
| Based on data recorded in July 2018 in the Changjiang River estuary and adjacent water bodies at three stations and five consecutive bedding face stations, we analyzed the particulate nitrogen (PN) and phosphorus (PP); particularly their distribution features, the migration process, and influencing factors. The results showed that the concentration of PN ranged from 0.75 to 27.42 μmol·L-1, and the average concentration was 5.39 μmol·L-1. The concentration of PP ranged from 0.72 to 2.05 μmol·L-1 with an average concentration of 0.37 μmol·L-1. PN and PP had good correlations with the suspended particulate matter (TSP), showing apparent homology. Stratification and tides have a great influence on the migration of PN and PP. Stratification was not conducive for the upward transportation of particles at the bottom, making the vertical distribution of PN and PP stratified. At the same time, the dirty water from the Changjiang River entered the highly concentrated saltwater. The formed front causes the large particles to settle rapidly west of the front, hindering the horizontal transport of particulate matter, nitrogen, and phosphorus to the sea. Affected by the tide, the migration of the Changjiang River's fresh water and the resuspension of bottom sediments have an essential impact on the periodic changes of PN and PP in the water. PN and PP in the bottom and middle levels of the upwelling zone are periodically changed by sediment resuspension. This work plays a vital role in analyzing the correlation between the distribution of chemical composition and hydrodynamic effects in the coastal area of the estuary. |
| Key words: Changjiang River Estuary particulate nitrogen and phosphorus stratification tidal |
