共查询到19条相似文献，搜索用时 171 毫秒
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基于2020年8月至11月在南海北部获取的声学多普勒流速剖面仪观测数据,利用后向散射强度数据估算得到相对体积散射强度并用其表征浮游动物生物量的相对大小,对相对体积散射强度的半月变化与具有半月周期的潮流动能进行相关性分析,进而分析天文大潮对声学估算的浮游动物生物量的影响。结果表明：半月周期的相对体积散射强度与潮流动能之间呈负相关关系,即天文大潮时,潮流动能较强,水体相对体积散射强度较低,浮游动物生物量则较小,天文小潮时则情况相反。初步推测其原因为：天文大潮时,强潮流一方面导致浮游动物生存环境恶化,使其生物量下降,另一方面也改变了浮游动物垂直迁移特性,浮游动物迁移到近海底处使其难以被观测。 相似文献
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基于声学仪器与粒径分析仪研究东海浮游动物昼夜垂直迁移过程 总被引：1，自引：0，他引：1
浮游动物的昼夜迁移活动与其种群变动和摄食节律紧密联系,浮游动物昼夜移动的研究已经成为种群动力学研究的一个重要组成部分。2013年夏季在浙江东部近海,结合声学多普勒流速剖面仪(ADCP)和激光粒径分析仪(LISST-100)等仪器进行了一次定点周日连续观测。通过声学反演方法,得到后向散射强度剖面的时间变化,结合LISST-100得到的水体悬浮物粒径谱,研究了浮游动物垂直迁移及其习性。分析发现了可能是精致真刺水蚤的一次昼夜垂直迁移过程,其在夜间进入跃层附近进食,白天蛰伏于底层低温高盐的台湾暖流水中,垂向迁移速度达到了0.05 m/s。LISST-100观测还发现在夜间跃层边界处大粒径颗粒聚集和100～150 μm大小的颗粒物的减少,水体中不同粒径的悬浮颗粒物有明显的昼夜变化节律,推测水体中不同层次生物群落结构存在昼夜差异。 相似文献
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在胶州湾内设置连续站(36°5'54″N,120°15'20″E),分别于2006-2007年分春季、夏季、秋季、冬季四季进行垂直分段拖网,研究了胶州湾浮游动物垂直移动的规律。结果显示,浮游动物在不同季节显示不同的垂直迁移行为。同时,对该海域出现的优势种类的垂直移动规律进行了研究并分类,发现不同物种同一季节迁移方式不同,对于同一种类,在不同季节也表现出不同的迁移规律。因此,浮游动物垂直迁移规律不是一成不变的,由外界环境因子和内在因素共同作用决定。不同季节影响浮游动物垂直迁移的关键因子不同,其中春季、夏季、秋季三季主要影响因子是光照,冬季除了光照,还有温度、盐度和浮游植物密度。总体与温度和浮游植物密度正相关,与盐度负相关。对于不同种类,影响其垂直迁移的主要因子也不尽相同。 相似文献
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渤海海峡悬浮体分布、通量及其季节变化 总被引：1，自引：0，他引：1
渤海海峡是渤黄海物质交换的重要通道,同时也是黄河入海泥沙向黄海搬运的必经路径。本文以2006—2009年渤海海峡8个站位四个季节的悬浮体、CTD数据为基础,将标准层悬浮体浓度数据与浊度数据对比获得高垂直分辨率的悬浮体浓度数据,分析其季节变化特征,并结合日均风场驱动的高精度数值模型模拟的渤海海峡流场,计算了四个季节渤海海峡悬浮体通量。结果表明,北黄海冷水团的入侵和退缩是渤海海峡温盐及其季节变化的重要特征之一,四季节流场特征均为"北进南出";渤海海峡中上层悬浮体浓度分布为海峡南部浓度高、北部浓度低,夏季海峡北部下层北黄海冷水团控制海域悬浮体浓度高于周围水体。春季、夏季、秋季、冬季悬浮体浓度依次增高。观测期间渤海海峡悬浮体的年净通量约为251.63万吨,其中输往黄海方向的悬浮体通量约占黄河年平均输沙量的4.27%。 相似文献
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南黄海浮游植物季节性变化的数值模拟与影响因子分析 总被引：26，自引：1，他引：25
用三维物理-生物耦合模式研究南黄海浮游植物(以叶绿素a为指标)的季节变化.对于物理模式采用Princeton ocean model(POM),对于生物模式考虑溶解无机营养盐(氮、磷、硅)、浮游植物、食草性浮游动物和碎屑.给定已知的初始场和外加边界强迫,模拟了观测到叶绿素a的主要时、空分布特征,如浮游植物的春、秋季水华和夏季次表层叶绿素a极大值现象等.研究表明,浮游植物春季水华最先发生于黄海中央海域,主要原因是该海域透明度较高,流速较小.春季水华开始于垂直对流减弱和层化开始形成之前(约3月底至4月上旬),显著地依赖水层的稳定性.水体层化以后(约5～9月)叶绿素a浓度高值区分布在南黄海的南部和锋区.夏季的南黄海中央海域,由于上混合层营养盐几乎耗尽,限制了浮游植物的生长,在紧贴温跃层下部的真光层,具有丰富的营养盐和合适的光照,次表层叶绿素a极大值得以形成.秋季(约9～11月份,略迟于海表面开始降温的时间,随地点不同而异)随垂直混合的增强,有利于营养盐向上输运,浮游植物出现一次较小的峰值. 相似文献
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《中国海洋大学学报(自然科学版)》2015,(8)
为研究黄、东海浮游动物的种类组成及生物多样性特征,本文利用2006—2009年在黄海和东海进行的4个季节的断面调查所获得的大中型浮游动物样品进行了分析,并探讨了浮游动物与海洋环境因子的关系,特别是黑潮流系对黄、东海浮游动物物种多样性分布的影响。结果显示,4个季节共记录到浮游动物种类850个、浮游幼虫37类,合计种类887个。浮游动物的物种多样性存在显著的季节变化,但4个季节的生物多样性平面分布趋势基本一致,即黄海东海近岸东海外海。在黄海,多样性的纬向梯度较小而趋于均匀;而在东海,浮游动物的物种多样性变化梯度很大,呈现从外海到近岸、从南到北逐渐降低的趋势。浮游动物的物种多样性随黑潮流系影响的减弱而逐渐降低。黄海和东海的浮游动物群落存在显著差异。东海浮游动物群落的出现是黑潮流系对暖水种输运的结果。 相似文献
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南黄海中部悬浮体浓度垂直分布及其季节变化对该海域泥质区的生成有重要意义,为研究黄东海物质交换、南黄海中部泥质区生成机制,利用2006年至2009年四季节的温度、盐度数据,结合水样抽滤获得的悬浮体质量浓度数据和LISST观测到的悬浮体体积浓度数据分析南黄海中部断面悬浮体浓度垂直分布及其季节变化。结果表明,悬浮体LISST体积浓度和抽滤质量浓度具有较好的相关性,并将夏冬两季悬浮体体积浓度转换为质量浓度。四季节悬浮体浓度整体上表层低于底层,潮流是控制南黄海悬浮体分布的重要动力因素,秋季大潮期悬浮体浓度高于冬季小潮期,冬春两季悬浮体浓度分布相类似;受到强台风影响,夏季悬浮体浓度高于秋冬季,以温跃层为界,底层悬浮体浓度较高,最高达26.9mg/L,以细粉砂粒级为主,上层悬浮体浓度低于2mg/L,悬浮颗粒粒径大于31.6μm。夏季,黄海冷水团西边界锋面处为粉砂为主的高悬浮体浓度区,与南黄海中部泥质区西侧厚沉积带位置对应。冬季,黄海西部沿岸流流经区域悬浮体以极细砂粒级为主,黄海暖流海域各个粒级悬浮体浓度都比较高,以粉砂粒级以上为主,整个断面中较粗颗粒的悬浮体含量较多。 相似文献
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利用深海潜标所搭载的声学多普勒流速剖面仪(acoustic doppler current profiler,ADCP)得到的后向散射强度Sv,研究了黑潮-亲潮混合区浮游动物的垂向分布、其昼夜垂直迁移(diel vertical migration;DVM)的基本特征、多时间尺度变化及对反气旋式中尺度暖涡的响应.结果表... 相似文献
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南黄海浅水陆架区是我国重要经济海域之一,对该海域海流结构的研究是研究陆架环流的一个重要环节。虽然关于这项研究的论著颇多。但根据描述统计学方法研究中国海海流结构的论述至今却极少。本文根据我国海洋地质调查局较长时间的海流观测资料，以描述统计学的分析方法,对南黄海实测流速的统计特征进行了初步分析。
文中引用的实测流速数据的观测站分布于偏近我国的南黄海陆架上。共选取三个观测站,分别以A,B,C标示,三者近似地呈等腰三角形分布,A,B站的连线近似地与经线平行。观测日期颇长,分别是1975年4-5月。1976年4-8月和1977年4-7月。本文着重研究南黄海近表层(5米层)4-6月实测流速谱的特性,所以,统计分析结果反映的是南黄海近表层海流在春夏交替季节的特性。实测流速数据的采样时间间隔均取每15分钟一次。观测仪器系国产HLP1-1印刷海流计。各观测站上截取的观测数据组数见表1。 相似文献
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《Deep Sea Research Part I: Oceanographic Research Papers》2007,54(4):608-636
Temporal variability of acoustically estimated zooplankton biomass at the Bermuda Testbed Mooring (BTM) site in the Sargasso Sea (at 31°43′N, 64°10′W) is described for time scales from less than an hour to the seasonal cycle primarily using data obtained between August 1996 and November 2000, and from May 10 to November 13, 2003. Concurrent high frequency BTM observations of meteorological, physical, and bio-optical variables are used to interpret processes contributing to the zooplankton variability. Zooplankton biomass estimates are derived from regressions of backscatter intensity data measured with an upward looking 153-kHz acoustic Doppler current profiler (ADCP) and zooplankton net tow data collected near the BTM site as part of the Bermuda Atlantic Time-series Study (BATS). Our data show clear event-scale variations. Peaks are associated with annual spring blooms involving mixed layer shoaling and in some cases passages of mesoscale eddy features. Biomass peaks are often coincident with maxima seen in BTM chlorophyll fluorescence measurements (inferred phytoplankton biomass). Some storm events do not appear to manifest in significant perturbations of zooplankton distributions; however, Hurricane Fabian (2003) greatly impacted these distributions. Estimates of zooplankton biomass and relative vertical velocity show the vertical structure of daily migration patterns. Seasonal variations in migration patterns are also evident, with diel changes in zooplankton biomass most pronounced in spring and least pronounced in winter. In summary, our high temporal resolution time series of estimated zooplankton biomass in the open ocean provide information on scales inaccessible through conventional monthly ship-based sampling. These data have implications for upper ocean ecology and the vertical transport of carbon and nitrogen through the diel migration of zooplankton. 相似文献
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Acoustic volume backscattering strength data were collected and Conductivity Temperature Depth (CTD) measur e m e n t s were
conducted in the southern Yellow Sea in summer 2005 and 2006. The high temporal and vertical resolution acoustic data measured
with a 307 kHz Acoustic Doppler Current Profiler (ADCP) and a 250 kHz acoustic Doppler profile (ADP) had dominant diel variation,
which resulted from vertical migration of sound scatterers. Some scatterers congregating in the bottom layer in the daytime
migrated upward at dusk, and migrated downward into the bottom layer at dawn. The migration speeds were estimated. More than
33 days data show that the diel migration varies with time. The feature of migration measured with ADCP and ADP is consistent
to some extent with what is described in the study on vertical migration of zooplankton in the southern Yellow Sea with conventional
net samples. 相似文献
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基于Argo数据的吕宋海峡东部海域的会聚区特征分析 总被引：2，自引：0，他引：2
利用2010-2013年的Argo浮标观测资料,对吕宋海峡东部海域(19°~23°N,123~127°E)的会聚区特征进行综合分析。研究结果如下:(1)吕宋海峡东部海域4个季节表面的声速从大至小依次为夏季、秋季、春季和冬季,夏季最大为1 543.5m/s,冬季最小为1 533.4m/s;混合层深度从大到小依次为冬季、秋季、春季和夏季;(2)采用WOA13气候态数据对声速剖面进行深海延拓,获得全海深的声速剖面,分析4个季节的声道特征。声道轴深度和声速较为稳定,声道轴深度在1 000~1 040m之间,声道轴处的声速为1 482m/s,4个季节的平均声道厚度都超过4 500m,利于会聚区形成;(3)研究区较易发生会聚现象,发生会聚现象概率高于50%的占70.6%;会聚现象的发生概率季节变化明显,春季、冬季极易发生声场的会聚现象,夏季最小;(4)运用RAMGeo声场模型对研究区4个季节的声传播损失进行仿真,分析会聚区的季节变化特征。当声源深度100m,接收深度10m时,第一会聚区,离声源的距离在61~64km左右,夏季离声源最近,春、冬季较远;会聚区宽度上,夏季最宽为10km,春季最窄为4.6km;会聚区增益分布特点与会聚区宽度刚好相反,春季最大为14.6dB,夏季最小为8.5dB。 相似文献
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Diurnal Cycle of Sound Scatterers and Measurements of Turbidity Using ADCP in Beppu Bay 总被引：2，自引：0，他引：2
Xiao-Hua Zhu Yoshio Takasugi Masayuki Nagao Eisuke Hashimoto 《Journal of Oceanography》2000,56(5):559-565
From September 20 to 22 in 1994, the vertical profiles of echo intensity and three-component velocities were measured with a bottom-mounted 300 kHz broadband acoustic Doppler current profiler (ADCP) in Beppu Bay in the Seto Inland Sea of Japan. A very strong thermocline was observed from 50 to 60 m. A pronounced diurnal cycle of backscatter strength (BS) was found above the thermocline. However, it was not found under the thermocline where there was a lack of dissolved oxygen. We suggest that the diurnal cycle of BS is caused by the vertical migration of zooplankton. The downward and upward migration occurred in early morning and late afternoon, respectively. The migration speeds estimated from BS isopleth displacements were about 1 cm s–1. Further, the contribution of turbidity (Tur) to BS was examined by separating out the effect of migrating zooplankton. There was a significant correlation between BS and turbidity under the thermocline. The maximum contributions of the Tur, migrating zooplankton and non-migrating plankton on BS were estimated at 3, 12, 25 dB, respectively. These data suggest that when using an ADCP to estimate Tur, it is very important to consider carefully the backscatter signal from zooplankton. 相似文献
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The paper presents the results of an analysis of hydrological data obtained on cruise 89 of the R/V Professor Vodyanitskii from September 30 through October 19, 2016, in the central area of the northern Black Sea. Currents were measured using a lowered acoustic Doppler current profiler (LADCP) to a depth of 350 m. Examples of the current velocity profiles and conditional density at individual stations are presented. The averaged characteristics of the vertical current structure in the seasonal and permanent pycnoclines are discussed. The isopycnally averaged kinetic energy (KE) demonstrates an almost linear dependence on the conditional density (σθ). In the seasonal pycnocline, EK = 0.2–0.013σθ; in the permanent pycnocline, EK = 0.12–0.007σθ. An interpretation is given for the variability of the kinetic energy with depth. It is shown that the maxima of the averaged vertical shear profile correspond to the occurrence depth of the seasonal and permanent pycnoclines. The mean Richardson number has a value of ~10 in the upper sea layer and decreases with depth, assuming a value of ~3 at the 300 m horizon. The estimate for the vertical turbulent diffusion coefficient from the simplified model shows its increase with depth. 相似文献
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Seok Lee Heung-Jae Lie Cheol-Ho Cho Sok Kuh Kang William J. Teague Kyung-Il Chang Kyu-Min Song Kyung-Hee Oh 《Ocean Science Journal》2011,46(2):73-84
The vertical structure of the M2 tidal current in the Yellow Sea is analyzed from data acquired using an acoustic Doppler current profiler. The observed vertical
profiles of the M2 tidal current are decomposed into two rotating components of counter-clockwise and clockwise, and restructured using a simple
one-point model with a constant vertical eddy viscosity. The analyzed results show that the internal fictional effect dominates
the vertical structure of the tidal current in the bottom boundary layer. In the Yellow Sea, the effect of the bottom friction
reduces the current speed by about 20–40% and induces the bottom phase advance by about 15–50 minutes. In the shallower coastal
regions, the effects of bottom topography are more prominent on the vertical structure of tidal currents. The vertical profile
of the tidal current in summer, when the water column is strongly stratified, is disturbed near the pycnocline layer. The
stratification significantly influences the vertical shear and distinct seasonal variation of the tidal current. 相似文献
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基于日本海洋信息中心提供的东海黑潮PN断面CTD资料,本文采用动力高度法计算了1991-2011年间90个航次的断面流速,并对流场结构、最大流速、流幅和流量进行了统计分析。结果表明:东海黑潮PN断面流场存在单核、双核、多核3种结构;其中单核结构出现的概率为50%,双核结构为39%,多核结构为11%。东海黑潮的流结构存在显著的季节变化:秋季多核结构所占的比重为4个季节最大,平均流核数最多;冬季主要为单核结构,平均流核数最少;夏季和春季则没有明显的倾向性,单核、双核、多核3种结构出现概率相近,平均流核数介于秋季和冬季之间。其次东海黑潮的流量也存在显著的季节变化:冬季与夏季最强,秋季最小,春季居中。最后东海黑潮的最大流速和流幅也存在季节变化:夏季最大,秋季最小,春季和冬季居中。 相似文献