南黄海夏季温盐年际变化时空模态与气候响应

根据南黄海断面1977—2016年历年8月标准层温度、盐度与气候要素观测资料,采用时空分析等方法,分析了南黄海断面夏季温度、盐度年际时空变化与气候响应。断面温度主要有4种时空模态,夏季风生环流、冷水团强度、面积与断面冬季温度模态是主要温度模态年际变化的主要影响因素;夏季风生流场形态、春季PDO指数与断面冬季温度模态是次要温度模态年际变化的主要影响因素;温度模态时间分量均为准平衡态长期变化。断面盐度主要有4种时空模态,夏季苏北沿海低盐度水体、南黄海中部高盐度水体与夏季黄海风生流输送作用是盐度主要模态年际变化的主要影响因素;夏季南黄海降水量减少与风生流输送减弱是盐度次要模态年际变化的主要影响因素。盐度主要模态时间分量为准平衡态长期变化,次要模态时间分量存在显著线性低盐趋势变化。断面夏季温盐多年平均分布主要受到夏季多年平均风生环流影响。断面核心冷水团月平均温度为准平衡态长期变化;面积存在显著线性减小趋势,黄海风生流场季节与年际变化是南黄海核心冷水团年际变化主要影响因素,春季PDO指数对冷水团面积年际变化有显著非线性影响。断面冷水团、核心冷水团月平均盐度为显著线性低盐趋势周期年际变化。由于黄海温盐长期线性趋势变化,与30多年前状况相比,目前黄海温盐场季节循环时空变化形态可能已经发生显著改变。     

渤、黄海冬、夏季节风生流场年际变化时空模态与环流变异

根据1975—2017年冬、夏季节渤、黄海沿岸25个气象站风观测资料,采用二维非线性垂直平均风生流模式、旋转经验正交函数(REOF)等方法,研究了渤、黄海冬、夏季节平均风生流速度势与流函数场年际变化时空模态与环流变异.由于冬、夏季节渤、黄海风应力场强度年际变化显著线性减弱趋势,冬季渤、黄海平均速度势与流函数强度年际变化线性减弱速率大于夏季,黄海冬、夏季平均速度势与流函数强度年际变化线性减弱速率大于渤海.渤、黄海冬、夏季节平均风生流速度势与流函数场年际变化主要有两种时空模态,冬季渤海垂直环流显著线性减弱以及水平环流准平衡态年际变化是主要分量,冬季黄海垂直与水平环流准平衡态年际变化是主要分量.夏季渤海垂直环流显著线性减弱以及水平环流准平衡态年际变化是主要分量,夏季黄海大部分海域垂直环流显著线性减弱与局部垂直环流显著线性增强年际变化是主要分量,夏季黄海水平环流形态此消彼长显著线性增强及减弱年际变化是主要分量.冬季黄海暖流暖水向南黄海西侧以及向渤海中部输送过程是在3～4个环流之间传递形成,并非由单一环流输送形成.冬季渤海中部辐散下沉反气旋环流与黄海中部至渤海海峡的气旋环流、黄海东部辐散下沉反气旋环流是冬季黄海暖流强度与范围的控制环流,夏季渤海中部辐散下沉反气旋环流与黄海中部辐合上升气旋型环流是夏季渤、黄海冷水团强度与范围的控制环流,冬、夏季节渤、黄海控制环流年际变化形态的变换形成冬季黄海暖流与夏季渤、黄海冷水团暖年或冷年的年际变化.     

北黄海夏季溶解氧与表观耗氧量年际变化时空模态

根据北黄海夏季断面1976~2015年历年8月监测资料,采用时空分析等方法,研究了北黄海夏季断面溶解氧含量和表观耗氧量年际变化时空模态.溶解氧含量与表观耗氧量年际变化分别有3种主要时空模态,第一、二模态是近底层水体低氧、贫氧年际变化的主要影响分量,第三模态是混合层水体高氧、富氧年际变化主要影响分量.生物活性组分(BAC)耗-生氧与海洋环流输送增减氧过程是夏季溶解氧含量与表观耗氧量年际变化主要影响因素,温跃层强度年际变化不是主要影响因素.2001年后,表层月海气氧通量年际变化由氧汇分布为主转变为氧源分布,表层溶解氧含量增大以及生物活性组分生氧作用增强年际变化是这种转变的原因.北黄海夏季断面年平均溶解氧含量、表观耗氧量空间分布相似性较低,夏季断面年平均温度、盐度以及沉积物需氧、风生环流是年平均溶解氧含量、表观耗氧量分布的主要影响因素.生物活性组分耗-生氧过程是断面各层月平均溶解氧含量、表观耗氧量年际变化主要影响因素,温度变化是次要因素.由于断面水体低氧幅度与贫氧面积显著线性增大,与30多年前比较,黄海溶解氧含量、表观耗氧量场季节变化空间分布与时间形态已经发生改变.     

渤海夏季温盐年际变化时空模态与气候响应

根据渤海夏季断面1978~2014年历年8月温度、盐度与气候要素、黄河年径流量等观测数据,采用旋转经验正交函数(REOF)、风驱海流模式诊断、最大熵谱分析和延迟相关分析等方法,研究了渤海夏季断面温度、盐度年际变化时空模态与气候响应.温度主要有4种时空模态,其中第一模态为准平衡态年际变化和10a尺度跃变,第二至四模态为显著线性降温趋势年际变化和10a尺度跃变.渤海夏季径向风应力强度是夏季温度年际变化的主要影响因素,夏季风应力强度逐年减弱使得夏季水温的季节增温减弱,并且抵消了夏季气温逐年升高对水温的增温影响,温度模态大部分分量出现显著线性降温趋势.夏季大尺度海洋温度、气温年际变化是夏季温度年际变化的次要影响因素.盐度主要有2种时空模态,其中第一模态是对辽河口入海径流量、夏季降水量和夏季风应力强度的响应;第二模态是对黄河口入海年径流量和夏季风应力强度的响应.黄河口、辽河口入海年径流量与夏季降水量是盐度年际变化的主要影响因素,夏季风应力强度是次要因素.盐度模态年际变化呈现准平衡态周期变化和10a尺度跃变.     

渤、黄海风生流场季节循环时空模态与变异

根据1978—2015年渤、黄海沿岸观测风应力场与二维非线性垂直平均风生流模式,以及旋转经验正交函数（REOF）、调和分析等方法,研究了渤、黄海月平均风生流速度势、流函数场季节循环时空模态与年际变异.渤、黄海月平均风生流速度势、流函数场主要有两种时空模态,季节周期分量是时空模态的主要分量.由于风应力场季节循环变异,渤海流函数场季节时空循环变异程度大于速度势场,速度势、流函数场第二模态是季节变异的主要分量,黄海速度势场季节时空循环变异程度大于流函数场,速度势场第二模态是季节变异的主要分量.由于月平均风应力场强度年际变化显著线性减弱,渤、黄海季节平均风生流场强度年际变化也显著减弱.渤、黄海暖流与冷水团季节生消是风生流水平环流与垂直对流对冷 暖水体输送与汇集共同作用的结果,渤、黄海春、夏季辐合上升环流延缓及减弱了浅层暖水向深层传播,是春、夏季冷水团与温跃层形成的重要动力因素,因此,速度势是研究渤、黄海风生流场十分重要的因素.冬季渤海中部、黄海东部反气旋型及辐散下沉环流与黄海中部气旋型环流、辐合上升环流是黄海暖流季节转换与强度的主要动力控制因素,夏季黄海东部气旋型环流、辐合上升环流与黄海中部反气旋型环流、辐散下沉环流是黄海冷水团季节转换与强度的主要动力控制因素.     

渤海B1断面夏季温盐结构及变化趋势

采用特征量和线性拟合的方法,对1976～2003年8月的B1断面温盐调查资料进行分析.结果表明:夏季渤海暖水深入沿岸两端及渤海中部,深水处具有南北2个冷水区,形成冷、暖水体并存的分布特征.渤海夏季温度场结构分布是多种海洋物理环境要素的综合影响所致,太阳辐射和地形是基本原因之一,北黄海冷水侵入是冷暖水区维持的重要原因.冷水区多年温度有正变化率,温度变化正距平的信号来自大气气候变暖;而渤海中部高温水体则具有负变化率,温度变化负距平的信号来自北黄海次表层温度的变化,可能与北黄海冷水侵入渤海有关.夏季近岸盐度低,底层盐度高.盐度多年变化以正变率为主,造成岸边盐度升值明显的主要原因是河流入海淡水量的减少和工业污染.     

北黄海冬季温盐年际变化时空模态与气候响应

根据1977-2012年历年2 月份北黄海断面表底层温度、盐度观测资料,采用旋转经验正交函数（REOF）、跃变分 析、最大熵谱分析和延迟相关分析等方法,分析了断面温度、盐度年际变化时空模态和机制。断面表底层温度、盐度时空模 态主要有两种：开阔海型和近岸（近海） 型。温度、盐度模态的时间分量变化主要有准周期变化和线性趋势变化,温度模态 时间分量存在显著线性升高趋势。历年2月平均气温年际变化主要影响开阔海型温度模态,历年1 月经向伪风应力和年际变 化主要影响近岸型温度模态。盐度模态主要受渤南（鲁北）水和辽南水盐度年际变化影响,受渤南（鲁北） 水影响的盐度模 态,模态时间分量存在显著线性升高趋势;受辽南水影响的盐度模态,模态时间分量存在显著线性降低趋势,其中模态线性 升高的斜率大于模态线性降低的斜率。     

南黄海冬季温盐年际变化时空模态与气候响应

根据南黄海36°N断面1977-2013年历年2月表底层温度、盐度观测资料,采用旋转经验正交函数(REOF)、最大熵谱分析和延迟相关分析等方法分析了断面温盐年际变化时空模态和机制。断面表底层温度时空模态有二种:鲁南近海型和南黄海槽型,模态时间分量主要有准周期变化和线性趋势变化,表底层温度鲁南近岸型模态有显著线性升高趋势,表底层温度南黄海槽型模态准平衡变化。温度模态年际变化是对局地气温、风应力、黄海暖流、太平洋年代际振荡指数位相和ENSO事件的响应。断面表底层盐度时空模态有二种:鲁南近海型和南黄海槽型,模态时间分量主要有准周期变化和线性趋势变化,表层盐度南黄海槽型模态有显著线性降低趋势,表底层盐度鲁南近海型模态准平衡变化。表底层盐度模态是对辽南水、渤南沿岸水和黄海暖流水盐度年际变化的响应。     

北黄海冷水团温、盐多年变化特征及影响因素

基于1976~1999年的海洋调查资料,主要研究了北黄海冷水团温、盐的多年变化特征,并结合该时间区间内黄河径流量及海洋站的气温、风速等资料探讨影响北黄海冷水团温、盐变化的因素.结果表明,北黄海冷水团在这24 a间温度稍呈上升趋势(0.005℃/a),盐度升降趋势则不明显.其温度主要受冬季气温影响,黑潮现象会使温度变异.盐度主要受黄海暖流、渤海热通量、海域冬季大风的共同作用;黄河径流量可能不是影响北黄海冷水团盐度变化的主要因素,但其径流量的大幅度变化也会影响北黄海冷水团的盐度变化趋势.     

渤海夏季溶解氧与表观耗氧量年际变化时空模态

根据渤海断面1978~2014年历年8月温度、盐度和溶解氧观测资料,采用旋转经验正交函数(REOF)、最大熵谱和延迟相关等方法,研究了渤海夏季断面溶解氧含量和表观耗氧量年际变化时空模态.溶解氧含量主要存在4种时空模态:第一模态空间分量主权重在10 m以深水体;时间分量均为显著线性低氧趋势周期年际变化和10a尺度跃变.第二、四模态空间分量主权重在5 m以浅水体及断面南端底层;时间分量均为显著线性高氧趋势周期年际变化和10a尺度跃变.第三模态空间分量主权重在10 m附近;时间分量为准平衡态周期变化和10a尺度跃变.表观耗氧量主要有4种时空模态:第一、二模态空间分量主权重在中层及底层;时间分量均为显著线性贫氧趋势周期变化和10a尺度跃变.第三、四模态空间分量主权重在5 m以浅水体及断面南端底层;时间分量均为显著线性富氧趋势周期变化和10a尺度跃变.生物活性组分耗氧与海流输送减氧过程是夏季溶解氧、表观耗氧量模态显著线性低氧、贫氧趋势年际变化主要影响因素,饱和溶解氧强增氧、生物活性组分光合作用生氧和海流输送增氧过程是夏季溶解氧、表观耗氧量模态显著线性高氧、富氧趋势年际变化主要影响因素.渤海夏季深层水体中生物耗氧作用大于浅层水体中生物生氧作用,20 m以深水体中显著线性低氧、贫氧趋势快于20 m以浅水体的显著高氧、富氧趋势.生物活性组分氧化与光合作用是渤海夏季年际平均溶解氧含量、表观耗氧量分布以及溶解氧含量、表观耗氧量年际时空变化的主要影响因素,温度、盐度不是主要影响因素.     

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。     

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.     

Estimation of Sediment Properties during Benthic Impact Experiments

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.     

A Tidal Flow Model for the Gulf of Kachchh, India

A vertically integrated model has been used to study the tidal circulation and currents in the Gulf of Kachchh along the west coast of India. The model is fully nonlinear and uses a semiexplicit finite difference scheme to solve the basic hydrodynamic equations on a staggered grid. The model is forced by prescribing the tides along the open boundary of the model domain. The flow is simulated both with and without the presence of the proposed tidal barrage across the Hansthal Creek in the Gulf of Kachchh. The results show a considerable change in the behavior of the tidal flow in the presence of the barrage.     

利用中国GF-3卫星SAR和HY-2A卫星微波散射计的首次台风联合定量观测

<正>The typhoon,as a mature tropical cyclone that develops in the western part of the North Pacific Ocean with high wind speed and heavy rainfall,is one of the most lethal and costly of natural disasters for the densely populated countries of East Asia.It can be easily detected by space-borne sensors operated at microwave,visible or infrared bands(Liu et al.,2014).Synthetic Aperture Radar(SAR)is     

离子交换—原子吸收光谱法测定海水中痕量铜、铅、锌、镉、铁、锰

本文介绍了用国产D401型螯合树脂分离富集海水中铜、铅、锌、镉、铁、锰等痕量元素,并用原子吸收光谱仪测定其含量的方法。讨论了各元素的分离条件选择及干扰元素的影响,并与溶剂萃取法的结果作了比较。各元素检测的定量下限为:铜0.5μg/L、铅0.1μg/L、锌1.0μg/L、镉0.01μg/L、铁2.0μg/L、锰2.0μg/L。方法精密度在4—8％之间,回收率为90—102％。     

Biogeochemistry of Mangrove Soil Organic Matter: a Comparison BetweenRhizophoraandAvicenniaSoils in South-eastern Brazil

Soil core samples fromRhizophora mangleL. andAvicennia schauerianaStapf & Leech forests from south-eastern Brazil were analysed for their total organic matter content and their sugars, amino acid and amino sugars composition. Organic carbon and nitrogen contents were higher inAvicenniathan inRhizophorasoils. The contribution of sugars and amino acids to the total organic carbon pool was constant with depth inRhizophorasoils whereas inAvicenniasoils it increased. Spectral distribution of sugars and amino acids showed a dominance of Ca-affine monomers, particularly acidic amino acids, and the sugar arabinose. Biogeochemical indicators derived from ratios of individual sugar and amino acid monomers confirm previous studies which showed that organic matter in both soils is mainly of mangrove origin. The results further suggest accumulation of organic matter inRhizophorasoils and a continuing degradation of organic matter inAvicenniasoils. The latter may thus release more nutrients to adjacent ecosystems thanRhizophorasoils.     

A review of orange roughy Hoplostethus atlanticus fisheries,estimation methods,biology and stock structure

Orange roughy Hoplostethus atlanticus are unusual fish. They form dense aggregations that have fuelled lucrative fisheries at great depths (600–1 400 m), especially off Namibia, New Zealand and Australia. They are thought to be very long-lived (>100 years, maturity at 22 – 40 years), and to have exceptionally low natural mortality (M = 0.045–0.064 year^?1) and slow growth rates (K = 0.055–0.070 year^?1). In addition, they spawn large eggs and have low fecundity. These factors combine to make orange roughy highly susceptible to overfishing; most stocks are below 30% of pristine levels. Assessments are obtained from indices of catch rate and trawl, acoustic and egg surveys. Acoustic estimates are the most direct, but are confounded by the species' low target strength (?50 to ?53 dB)–attributable to the wax-filled swim bladder. Extracellular wax esters are stored in abundance and comprise mostly mono-unsaturated fatty acids, with low concentrations of the ω-3 fatty acid family. This unusual composition (resultant from the species' diet) ensures neutral buoyancy. Stock separation has been inferred mainly from biological studies, but genetic studies have also found differences among stocks within New Zealand and Australia. Deep-water habitat may be damaged by trawling operations and may take many years to recover, so in some quarters there is a call for a portion of suitable habitat to be set aside for preservation. Although Namibian orange roughy are shallower, smaller and younger than those in other stocks, the Namibian fishery sustained high catches for only a few years before quotas were reduced, from 12 000 to 1 875 tons. Three management lessons are suggested for developing orange roughy fisheries based on the Namibian experience: (1) imposition of catch limits during exploratory fishing; (2) starting the acoustic surveys earlier in the fishery, if possible; (3) greater reliance on trends in catch rate until a survey series has been established.