温盐深测量仪(CTD)资料质量对比分析

温盐深测量仪(CTD)是目前国际上应用最为广泛的物理海洋调查仪器设备之一。2014年,中国科学院海洋研究所在黄海布放的潜标上搭载了3种不同型号的CTD(37Coastal、CTD48和304Plus),本文分别对这3种CTD所获取的数据资料进行了对比分析。三者数据两两对比结果显示,37Coastal与CTD48压力及温度数据最为接近,盐度数据则为37Coastal与304Plus相差最小。3种设备的压力、温度及电导率数据稳定性对比结果如下:37Coastal压力数据稳定性表现最好;三者温度数据稳定性表现一致;而37Coastal盐度数据稳定性和CTD48一致。三种设备均能适应海洋真实的物理环境参数变化观测,同时各自有其不同的使用环境,对于不同海域环境使用需要进行详细评估,综合各个方面的因素确定最终适合自身科学研究需求的方案。     

走航式海洋多参数剖面测量系统(MVP)温度和电导率滞后效应的一种资料处理方法

走航式海洋多参数剖面测量系统(MVP)是一种集成程度和自动化程度都较高的海洋调查设备,能对多要素进行同时观测,获得高水平空间分辨率的数据资料。MVP由于温度和电导率传感器响应时间的不匹配,下放速度过快(峰值速度4m/s)而造成非常严重的盐度尖峰现象。本研究通过结合F法、GM法和Grose法提出的盐度尖峰订正方案,提出了一种新的方法Match conductivity and temperature response times法,对压力、温度和电导率传感器三者进行响应时间的匹配来减弱盐度尖峰。与SBE-9型CTD资料进行对比发现订正后的资料误差比订正前减小80%,与CTD盐度曲线互相关程度为0.917。对比35N断面修正前后的盐度资料发现订正后温盐跃层处出现的低盐区域消失,与CTD断面资料对比结果显示MVP资料比CTD资料在细结构上更具有优势。     

两型国产CTD海上比测试验结果分析

基于目前国内海洋仪器的现状,为了对国产温盐深剖面仪(Conductivity-Temperature-Depth profiler,CTD)的性能和实际使用情况有个量化的结果,在我国南海东北部海域对国内较为成熟且具备产品化条件的两型国产CTD开展第三方独立检验与验证。比测过程中,采用同架捆绑,同步下放的方法进行测量。数据处理时,采用一种简便的移相相关法,对国产CTD的压力(P)、温度(T)、电导率(C)、盐度(S)与标准CTD进行对比分析。试验结果表明两者数据曲线趋势一致,线形基本吻合,参试的国产CTD基本上达到自身产品标称精度,但低于标准CTD精度。本次比测结果有利于促进技术成果的完善与固化,有利于进一步提高设备的可靠性、稳定性和批量一致性,为国产海洋环境监测设备的规模化应用和推广提供数据支撑。     

“海翼号”水下滑翔机盐度数据的热滞后效应偏差订正方法探讨

水下滑翔机可以高效地观测海水的温度、盐度和压强等海洋参数,但由于热滞后效应,盐度数据,特别是在温度梯度较大的温跃层,会出现一定程度的偏差。本研究选取了3种目前常用的盐度热滞后订正方法,对带泵的“海翼号”水下滑翔机,于2019年8月在中北太平洋所观测的盐度数据因热滞后效应引起的偏差进行订正处理,与船载911型温盐深测量仪(Instrument for Measuring Conductivity Temperature and Depth,CTD)观测盐度进行对比,在比较了3种方法对滑翔机盐度订正前后下降和上升剖面偏差的减少程度、订正后剖面与船载CTD观测剖面的偏差大小和下降上升温盐曲线(T-S曲线)的一致程度后,得出了水下滑翔机盐度订正的最优方法,即在订正电导池中实际温度的前提下,采用计算机图形分割方法,最小化滑翔机机载CTD测得的下降和上升两个剖面T-S曲线围成面积所确定的目标函数,来确定合适的热滞后修正振幅和时间常数,从而修正下降和上升两个剖面之间盐度偏差。     

水下滑翔机温盐深观测数据处理研究

为提高水下滑翔机搭载的温盐深剖面仪(CTD)数据处理质量及效率,在船载CTD数据处理方法基础上,研究了国产水下滑翔机CTD数据处理方法,基于Matlab GUI编程技术设计与研发了水下滑翔机CTD数据处理软件,利用该软件处理了“海燕”水下滑翔机GPCTD观测数据并与船用SBE 911 plus CTD、XCTD及MVP300传感器成果数据进行了对比,结果表明：GPCTD观测数据经处理得到的温、盐、声剖面整体趋势与各传感器成果数据基本一致,数据质量介于各传感器之间,其中温度、声速与XCTD、MVP数据更接近,而盐度与CTD数据更吻合,本文研究将为规范处理与使用水下滑翔机海洋水文数据提供参考。     

SZC15-4型多参数剖面仪设计

CTD是测量海水温度、电导率和压力的仪器,在海洋科学考察、海洋资源调查开发、海洋环境监测预报和海洋军事研究中应用广泛。SZC15-4型多参数CTD是国产SZC15系列CTD最新型号,用于测量海水的温度、电导率、深度和叶绿素浓度,适用于近岸海洋调查。文中介绍了SZC15-4型多参数CTD剖面仪的性能、工作原理、系统组成和工作流程。并通过海上试验,与SBE19CTD在相同环境条件、相同采样速率下作比测,通过对实验数据做相关运算得出SZC15-4型CTD与SBE19在温度、盐度相关性优于0.999 9,表明两种仪器具有很高的相关特性。     

处理走航式海洋多参数剖面测量系统(MVP)温度和电导率滞后效应的方法

走航式海洋多参数剖面测量系统(moving vessel profiler,MVP)是一种集成程度和自动化程度都较高的海洋调查设备,能对海洋多要素进行同时观测,获得水平方向的高分辨率数据资料。由于温度和电导率传感器响应时间的不匹配,MVP下放速度过快(峰值速度4 m/s)而造成非常明显的盐度尖峰现象。本研究结合Fofonoff(F)法、时间常数指数递归数字滤波(Giles and McDougall,GM)法和Grose提出的盐度尖峰订正方案,提出了一种新的方法,即MCT(match conductivity and temperature response time)法,通过对压力、温度和电导率传感器进行响应时间的匹配来减弱盐度尖峰。将SBE-9型CTD资料作为标准,发现订正后的资料与CTD盐度曲线的互相关系数为0.917,误差比订正前减小80%。对比35°N断面修正前后的盐度资料,订正后温盐跃层处出现的低盐区域消失。MVP的应用比常规海洋调查仪器CTD对于海洋现象的观测更有优势。     

适用于水下滑翔器的CTD传感器设计

为满足水下滑翔器连续获取海洋剖面水文动力高质量数据的应用需求,利用自主研制的电磁感应式电导率传感器,集成快速响应的热敏电阻与压力传感器,以PIC18F2520单片机为电路系统的核心控制器,设计出一种适用于水下滑翔器搭载的微型化、低功耗、重量轻的SZQ1-1新型CTD传感器。该CTD测量仪经实验室多次标定,数据质量达到海试要求。2016年10月,该CTD传感器与海鸟SBE19 Plus在青岛胶州湾进行了海试比测。海试结果证明,该CTD传感器与SBE19 Plus测量结果相近,实时获取的温、盐、深剖面数据精度满足水下滑翔器的搭载要求。     

Argo、GTSPP与WOD数据集及其应用中需注意的若干问题

数据集整体的时空覆盖率制约了海洋科学研究的时空尺度,而海洋仪器的性能和观测方式直接决定了海洋数据的可靠性。以观测仪器作为主要衡量指标,结合数据集的时空覆盖率,对以温度和盐度为数据集主体的自持式拉格朗日环流剖面观测(Argo)数据集、全球温盐剖面数据集(GTSPP)、世界海洋数据集(WOD)进行分析和比对,确定了三者关系:Argo和GTSPP都是WOD的数据源,而GTSPP中包含了Argo实时数据的80%。在此基础上研究确定了目前温盐数据的主要观测仪器为Argo浮标、XBT和CTD,并对这三种仪器的误差来源和量级进行详细分析:由于全球自动观测与传输需求,Argo数据存在电子信号不稳定导致的随机误差,而且在高纬度强温跃层地带出现较强的虚假盐度尖峰,再是自由漂移的特性导致1%~2%盐度剖面漂移超过0.02 PSS-78;由于下降方程的不断演变,全球半数XBT数据提供者并未提供仪器型号,导致数据整体的可靠性下降;由于CTD基本采用船载观测,因此成本高、共享数据少且多集中近海。因此在对全球温盐数据进行应用时,应综合考虑观测仪器的可靠性和时空覆盖率,有效实现对资料本身误差和真实海洋现象的甄别。     

高精度CTD定标检测设备

CTD定标检测设备是高精度 CTD剖面仪和传感器进行计量检定、研制和生产的试验设备 ,其技术指标如下 :测量范围　　　　　　　准确度温度 :- 5～ 35℃± 0 .0 0 0 5℃盐度 :5～ 40± 0 .0 0 2压力 :0～ 30 MPa± 0 .0 1 % F.S.水槽恒温波动度 :± 0 .0 0 0 3℃水槽温场均匀度 :± 0 .0 0 0 3℃升、降温速度 :≥ 1 0℃ /h该设备的技术指标已取得国家计量研究院的检测证书。温度、盐度和压力标准可与国际接轨高精度CTD定标检测设备…     

Microbial Biomass and Organic Nutrients in the Deep-Sea Sediments of the Central Indian Ocean Basin

In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification

An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm.     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Deep-Sea Sediment Compression Curves: Some Controlling Factors, Spurious Overconsolidation, Predictions, and Geophysical Reproduction

Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations.     

INFORMATION FOR AUTHORS

<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,     

Evaluation of the Risk of Marine Slope Instability: A Pseudo-3D Approach for Application to Large Areas

This article presents a methodology developed to evaluate the instability of submarine slopes that extend over a large area. Special attention was paid to (1) the complex geometry (bathymetry) and the expanse of the slope, (2) the heterogeneity of the sediment, and (3) the distribution of the pore pressure. The safety factor was considered as a spatially varying quantity. The General Formulation (GLE, Fredlund and Krahn 1977), which fully satisfies equilibrium conditions, was used for evaluating the stability of the marine slope. The submarine slope failure, which occurred on 16 October 1979 during the construction of the new Nice airport, was studied in order to test the developed model. Geotechnical parameters were taken from experimental tests carried out by IFREMER on 19 cores extracted at different depths (from 27 m to 1300 m) (Cochonat, Bourillet, and Savoye, 1993; Mulder et al., 1994). Many scenarios were proposed in order to explain the cause of the Nice slope failure (Habib, 1994). In this article, two of those scenarios were tested. Simulation results are presented and discussed.