| 摘要: |
| 2014年冬季对西太平洋雅浦（Y3）海山区两条相交断面进行水文和悬浮体调查。利用温盐深仪（CTD）和深水型原位激光粒度仪（LISST-Deep）获取调查区各站位水体剖面的温度、盐度、叶绿素a浓度以及悬浮体体积浓度和粒度分布数据，对上层（350m以浅）水体的水文和悬浮体调查结果进行分析。结果表明：Y3海山对流经该海区的洋流产生影响，在海山顶部水体中形成具有上凸形态的温、盐跃层，在局部海域形成呈下凹形态的涡旋水文结构；受温、盐跃层的影响和控制，Y3海山上层水体中次表层叶绿素最大值层（SCML）的分布与温、盐跃层的水深范围（约50—160m）相一致，其荧光叶绿素a浓度总体小于1μg/L；Y3海山上层水体的悬浮体总体积浓度在0—120μl/L之间变化，其中悬浮体体积浓度的高值水层集中分布在SCML中，且悬浮体粒度分布存在5个峰值粒级，分别为15.4、68.6、95.5、185和304μm；其中15.4μm粒级的悬浮体体积浓度最低，但其与水层中荧光叶绿素a浓度的相关性最好，反映了水层中微型浮游植物的浓度与荧光叶绿素a浓度关系比较密切；其他4个较大峰值粒级悬浮体可能由小型或中型浮游生物（及其絮凝集合体）等构成，体积浓度较高，对水体叶绿素a浓度的影响很小；Y3海山区东侧Y3-14站的悬浮体组成和分布不同于其他站位，可能有未知的环境因素影响该站位的悬浮体组成和分布。本文研究结果可为进一步开展海山区沉积和生态环境研究提供参考和依据。 |
| 关键词: 热带西太平洋 雅浦海山 叶绿素最大值层(SCML) 悬浮体 粒度 |
| DOI：10.11693/hyhz20170300073 |
| 分类号:P736.21 |
| 基金项目:中国科学院战略性先导科技专项（A类），XDA11030103，XDA11030202号；国家自然科学基金项目，41476045号。 |
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| SUBSURFACE CHLOROPHYLL MAXIMUM LAYER IN YAP (Y3) SEAMOUNT AREA IN THE WESTERN PACIFIC DURING WINTER: DISTRIBUTION AND INFLUENCE ON PARTICLE SIZE DISTRIBUTION OF SUSPENDED PARTICULATE MATTER |
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WANG Zhen-Yan1,2,3, ZHANG Hong-Ge1,4, GAO Wei1,4
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1.Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;2.Key Laboratory of Marine Geology and Environment, Chinese Academy of Sciences, Qingdao 266071, China;3.Laboratroy for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China;4.University of Chinese Academy of Sciences, Beijing 100049, China
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| Abstract: |
| In this study, hydrology and suspended particulate matter (SPM) in two intersecting sections crossing the Yap (Y3) seamount area in the western Pacific during the winter of 2014 were investigated. We obtained temperature, salinity, and concentration of fluorescent chlorophyll a (chl a) by using Conductivity, Temperature, and Depth (CTD) Profiler, and measured the volume concentrations and particle sizes of SPM with Laser In-Situ Scattering and Transmissometry-Deep (LISST-Deep) instrument. The results demonstrated that firstly, the topography-current interactions over the Yap (Y3) seamount changed the hydrologic structure of the seawater overlying the seamount; specifically, the seamount elevated the thermocline and halocline in the water column at seamount summit and created a local anticyclonic eddy (station Y3-12) east of the seamount. As a result of the elevated thermocline and halocline, the subsurface chlorophyll maximum layer (SCML) above the seamount was located at the same depth range as the thermocline and halocline (approximately 50 to 160m), and there was upwelling at the seamount summit and downwelling in the eddy area. The highest fluorescent chl a concentrations in the SCML occurred mainly within a depth range from 60 to 120m. The fluorescent chl a concentrations were generally less than 1μg/L. The total volume concentration of the SPM over the Y3 seamount varied between 0 and 120μL/L. The highest volume concentrations of SPM were concentrated within the SCML. The particle size structure of the SPM in the SCML displayed 5 peak size fractions: 15.4, 68.6, 95.5, 185, and 304μm. The 15.4μm size fraction had the smallest volume concentration but the best correlation with the concentration of fluorescent chl a (R=0.5241). We infer that the SPM in this size fraction consisted primarily of nanophytoplankton. The SPM in the other 4 peak size fractions had little effect on the concentration of fluorescent chl a. We infer that these fractions consisted of micro- and mesoplankton. |
| Key words: the tropical western pacific Yap seamount subsurface chlorophyll maximum layer (SCML) suspended particulate matter (SPM) particle size |
