夏季东海陆架区悬浮体分布特征及其影响因素分析

发布时间：2018-01-11 07:37

本文关键词：夏季东海陆架区悬浮体分布特征及其影响因素分析　出处：《中国科学院研究生院(海洋研究所)》2015年硕士论文　论文类型：学位论文

【摘要】：本文依据2012年6~7月在东海所取得的水文和悬浮体现场调查资料,对夏季东海陆架区水体中悬浮体的分布特征进行了系统研究,并探讨了水团、浙江沿岸上升流、跃层以及海底沉积环境对研究区悬浮体分布的影响。结果表明:研究区上层水体(表层~30m)中悬浮体质量浓度、悬浮体体积浓度、悬浮体平均粒径和荧光叶绿素浓度均表现为近岸高、外海低的分布特征,悬浮体有效密度则表现为近岸低、外海高的分布特征。随深度的增加,悬浮体质量浓度总体变化不大,近岸海域悬浮体体积浓度,悬浮体平均粒径和荧光叶绿素浓度均逐渐降低,悬浮体有效密度则逐渐增大。底层水体中悬浮体质量浓度和悬浮体体积浓度均高于上层水体,且近岸高于外海;悬浮体平均粒径在近岸与外海间呈现一条平行海岸的高值条带;水体中荧光叶绿素浓度低于上层水体,且近岸高于外海;悬浮体有效密度近岸低、外海高,近岸海域高于上层水体,外海区低于上层水体。研究区水体中悬浮体体积浓度和荧光叶绿素浓度的断面分布表现出良好的相关性。近岸盐跃层、外海温跃层以及受上升流影响的深度范围内,水体中悬浮体体积浓度和荧光叶绿素浓度均体现为高值特征;外海上部水体中悬浮体体积浓度和荧光叶绿素浓度均体现为相对低值,且二者等值线的分布趋势总体一致。研究区悬浮体的分布特征主要受到陆源冲淡水、浙江沿岸上升流、温跃层和海底沉积环境的影响,其中陆源冲淡水、浙江沿岸上升流和水体中温跃层对研究区的“叠加”影响是主要因素。夏季陆源冲淡水和浙江沿岸上升流会给近岸海域带来丰富的营养盐,使浮游植物得以大量繁殖;温跃层的存在则会造成水体垂向稳定度的增加,同样有利于浮游植物的生长和繁殖;而浮游植物的富集则会导致水体中悬浮体体积浓度、悬浮体平均粒径、荧光叶绿素浓度的增大以及悬浮体有效密度的降低。风浪和潮流所引发的海底沉积物的再悬浮作用会造成底层水体中悬浮体质量浓度和悬浮体体积浓度较上层水体呈现为高值,荧光叶绿素浓度较上层水体呈现为低值,同时底层水体中的大量再悬浮物质的存在可能会造成部分海区底层悬浮体发生广泛的絮凝作用而使悬浮体平均粒径增大、有效密度降低。
[Abstract]:According to 2012 6~7 obtained in the East China Sea water and suspension of the spot investigation data, the distribution characteristics of suspension water continental shelf of the East China Sea in summer are studied, and discussed the water masses, Zhejiang coastal upwelling, the thermocline and seabed sediment environment on the study area the distribution of suspended matter. The results showed that the study area of upper water (surface ~30m) in suspension concentration, suspension concentration, suspension of average particle size and fluorescence of chlorophyll concentration showed a high distribution of coastal, offshore low, suspension is the effective density distribution of open coastal low. With the increase of depth, the suspension concentration changed little overall, inshore suspension volume the concentration of suspended matter, average particle size and concentration of chlorophyll fluorescence decreased gradually, suspension density gradually increases. The effective concentration of the bottom water in suspension And the suspension volume concentration was higher than that of the upper water and coastal waters off the coast of suspension; average particle size in the nearshore and offshore has a high value of strip parallel to the coast; fluorescence chlorophyll concentration lower than the upper water and coastal waters off the coast of suspension; effective density of coastal low, high sea, coastal waters is higher than that of the upper water. Sea area is lower than the upper section. The water distribution of the water in the study area in suspension concentration and fluorescence of chlorophyll concentration showed a good correlation. The nearshore sea thermocline and halocline, by the effects of upwelling depth range in water suspension concentration and fluorescence of chlorophyll concentration are reflected in the high values of sea water in the upper; the suspension concentration and fluorescence of chlorophyll concentration are relatively low value, the distribution trend and the two contours of the overall distribution in this area. The suspension The main feature is the terrigenous fresh water, Zhejiang coastal upwelling, effects of thermocline and sea sedimentary environment, the terrigenous fresh water, Zhejiang coastal upwelling and the thermocline on the "superposition" is the main factor affecting the summer. Terrigenous diluted water and Zhejiang coastal upwelling will bring abundant nutrients to coastal waters the phytoplankton to multiply; thermocline water will cause the increase of the vertical stability, is also conducive to the growth and reproduction of phytoplankton; while phytoplankton enrichment will lead to concentration of suspension in water suspension volume, average particle size, the concentration of chlorophyll fluorescence and the increase of effective density reduced. Suspension caused wave tide and sediment resuspension caused by bottom water in suspension concentration and suspension volume concentration is present in the upper water High value, fluorescence chlorophyll concentration is lower than upper layer water. Meanwhile, the presence of a large number of re suspended substances in bottom water may cause extensive flocculation of suspended solids in the bottom of some sea areas, which will increase the average particle size and decrease the effective density of suspended solids.

【学位授予单位】：中国科学院研究生院(海洋研究所)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P734.23

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