| 摘要: |
| 海山可以通过与洋流的相互作用改变水体结构，促进悬浮体以及海洋生物的再分配，进而影响海洋生物地球化学过程，促进大洋物质和能量交换。西太平洋有着复杂的环流结构，也是海山分布最多的海区之一，但目前人们对西太平洋海山区的悬浮体分布及其控制机制知之甚少。对2017年夏季在西太平洋卡罗琳M4海山区获取的水文及悬浮体资料进行分析。结果表明，M4海山区的悬浮体由生物碎屑、矿物颗粒和絮凝体等组成。海水的强烈层化阻碍了该海山区下层营养物质的上涌，使上层水体呈现出寡营养的特征，导致大部分站位悬浮体丰度较低；但在海山顶部，潮流和海山地形相互作用在山顶上方形成反气旋环流，不仅促进了深水的营养物质向上扩散，使得荧光叶绿素a浓度升高，同时对平流输送来的以及从深水中上涌的悬浮体起到了滞留作用，使山顶上方的悬浮体丰度远高于离山顶较远的位置。随着水深的增大，温、盐跃层的强度减弱，水体中的营养盐浓度升高，为浮游生物的生长提供了适宜的环境，进而使生物碎屑及絮凝体的丰度升高。北赤道潜流挟带来自西太平洋近岸海区的陆源矿物颗粒到达M4海山区，使该海山区300-500 m水层中的矿物颗粒丰度显著增加。 |
| 关键词: 悬浮体 卡罗琳M4海山 海水层化 洋流 西太平洋 |
| DOI：10.11693/hyhz20220800219 |
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| 基金项目: |
附件 |
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| DISTRIBUTION OF SUSPENDED PARTICULATE MATTER IN THE CAROLINE M4 SEAMOUNT IN THE WESTERN PACIFIC OCEAN AND ITS INFLUENCE FACTORS |
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SHI Xing-Yu, WANG Zhen-Yan, GAO Wei, HUANG Hai-Jun
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Institute of Oceanology, Chinese Academy of Sciences
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| Abstract: |
| Seamounts can change the hydrological structure through their interaction with ocean currents, promote the redistribution of the suspended particulate matters and marine organisms, and then affect the marine biogeochemical process and promote the exchange of materials and energy of the ocean. The Western Pacific has a complex circulation structure and is also one of the ocean areas with the most seamounts. However, at present, people know little about the distribution of the suspended particulate matters around the seamounts of the Western Pacific and its control mechanism. The hydrological and suspended particulate matter data obtained in the Caroline M4 seamount of the Western Pacific in summer 2017 were analyzed. The results showed that the suspended particulate matters in the M4 seamount were composed of organic debris, mineral particles and flocs. The strong stratification of sea water resisted the upwelling of nutrients and made the upper water oligotrophic. The abundance of suspended particles at most stations was low. However, the interaction between tidal current and the seamount generated anticyclone circulation above the top of the seamount, which not only promoted the upward diffusion of nutrients and increased the concentration of fluorescent chlorophyll a, but also retained suspended particles, so that the abundance of suspended particles on the top of the seamount was far higher than that far away from the seamount. As the strength of the thermocline weakening, the concentration of nutrients increased, providing a suitable environment for the growth of plankton. The abundance of organic debris and flocs also increased. The North Equatorial Undercurrent carried the terrigenous mineral particles from the coastal sea area of the Western Pacific Ocean to the M4 seamount, which significantly increased the mineral particles abundance between 300-500m of the seamount. |
| Key words: Suspended Particulate Matter (SPM) the Caroline M4 seamount seawater stratification ocean current Western Pacific Ocean |