BEHAVIOURS OF SUSPENDED PARTICULATE MATERIALS IN CHANGJIANG ESTUARY

The paper deals with the distribution of suspended particulated materials (SPM) in the Changjiang Estuary, the relation of salinity to particulated organic carbon and particulated organic nitrogen, and behaviour of SPM in mixing river-sea water. At the same time, the article shows that the SPM in Changjiang River emptying into the sea contains a large amount of organic matter. The relative concentrations of suspended particulate organic matter and living organic matter gradually increase seaward. In the estuarine environment, there is a linear relationship between log SPM and C/N ratio during the mixing of fresh water with seawater.     

Effects of deepening the Elbe Estuary on sediment regime and water quality

Changes in the transport and sedimentation of suspended particulate matter (SPM) after deepening of the navigation channel of the Elbe Estuary in 1999 were studied. Long-term series of the grain size composition of sediments and sedimentation rates in the main stream and its branches (Nebenelben) were compared with changes in flow velocities and tidal water levels. In addition, water quality parameters like biological oxygen demand (BOD₇), dissolved oxygen and particulate organic carbon (POC) were analysed to determine changes in the origin and fate of the SPM. In the main stream, deepening produced no significant changes of the flow velocities. However, there was a decrease of the mean tidal low water level between 5.7 and 8.1 cm at the upper end of the estuary. These small changes in hydrology had the effect that fine-grained suspended matter derived from freshwater run-off accumulated in the surface water of the freshwater region in the estuary and remained within this region until all degradable organic matter was consumed. Accumulation of the fine-grained SPM produced an increase of the <63 μm fraction in the sediments of the Hamburg harbour by about 20% and in the SPM along the freshwater longitudinal profile up to about 120%. Coupled to this the mean BOD₇ increased between May and August by 38%. Enhanced oxygen deficiencies thus occurred after 1999, with concentrations of below 6 mg O₂ L⁻¹ over a length of about 100 km along the freshwater longitudinal profile of the Elbe Estuary. In the shallow water regions present in the branches of the main stream, deepening of the navigation channel was followed by a 25% decrease in the flow velocities during low tide. This was coupled to an increase of the sedimentation rates which produced a rise of the sediment level between 0.7 and 1.5 m until 2004 and a permanent loss in the capacity of the branches for re-aeration of the open water. The results indicate that in tidal systems SPM might be more sensitive for monitoring changes in the transport regime than hydrological parameters.     

Chemical determination of particulate nitrogen in San Francisco Bay. A comparison of two estimates

Particulate nitrogen was measured by both the ultra-violet light-catalyzed peroxide method and the high temperature combustion method. The difference between values obtained with the two methods (combustion minus UV) was found to be linearly correlated with the concentration of total suspended particulate matter (SPM) in the sample. The slope of this correlation was taken to be the concentration of refractory nitrogen associated with the suspended matter, which may be ammonium ions fixed in lattices of clay minerals or organic nitrogen compounds did not vary significantly with SPM, location, water depth or salinity. Refractory nitrogen concentration were possibly related to concentrations of chlorophyll a and to cruise date, but in neither case was the evidence conclusive. Based on the indirect evidence presented, the UV method appears to provide a good measure of biologically reactive nitrogen in this system.     

白令海北部悬浮体含量分布及其颗粒组分特征

对中国第四次北极科学考察期间在白令海北部获取的海水样品进行悬浮体含量及其颗粒组分特征的分析。结果表明,白令海陆架海区悬浮体含量大体呈现出表层浓度低而底层浓度高的特点。表层海水悬浮体含量在白令海峡西侧和陆架东侧靠近阿拉斯加沿岸含量较高,而底层海水中悬浮体含量则在白令海峡西侧,以及白令海陆架西南部的圣马修岛西北侧较高。陆架流系对底床物质的再悬浮作用致使白令海悬浮颗粒物浓度的高值区多位于近底层海水中。受白令陆坡流沿陆架坡折带输运作用,研究区西南部悬浮体浓度较高。白令海陆架水以及阿纳德尔流携带悬浮颗粒向北输运,使得底层悬浮体浓度呈现出自南向北逐渐减弱的模式。圣劳仑斯岛以北靠近楚科奇半岛一侧海域,受高营养盐的阿纳德尔流的影响,悬浮颗粒物以藻类为主;东侧阿拉斯加沿岸流区悬浮颗粒则以陆源的碎屑矿物为主。     

Suspended particulate matter in the St. Lawrence estuary and Gulf surface layer and development of a remote sensing algorithm

Remote sensing of chlorophyll concentration is potentially affected by the presence of inorganic matter in the water column. Seasonal variability of total suspended particulate matter (SPM) concentration and its partition into organic and inorganic fractions was thus measured in the estuary and Gulf of St. Lawrence during five cruises. These measures were made in the surface layer down to the depth of the 0.1% light level. Results indicate that vertical variability was small for the entire study area. Data analysis lead to the definition of two main regions having different SPM characteristics: 1) the estuary zone characterized by a strong spatial variability, intermediate SPM concentrations and a clear spring phytoplankton bloom that is combined to an increased inorganic matter load; 2) the gulf region characterized by a relatively low SPM concentration and phytoplankton blooms in the spring and fall periods. Combined with in situ measurements of remote sensing reflectances, the database was used to validate existing inorganic matter retrieval algorithms and develop a new one better adapted to the low concentrations encountered in the St. Lawrence estuary and Gulf.     

Semidiurnal Dynamics of Salinity, Nutrients and Suspended Particulate Matter in an Estuary in the Seto Inland Sea, Japan, during a Spring Tide Cycle

The physical and chemical variability of the water column at subtidal station of an estuary in the Seto Inland Sea, Japan, was studied over a 24-hour period during a spring tide (tidal range ca. 2 m) in May 1995. Surface water and several depths through the water column were monitored every one and two hours, respectively. At each occasion, water temperature, salinity and dissolved oxygen concentration were measured and water samples were collected for the determination of nutrients and suspended particulate matter (SPM). Disruptive changes in the physical and chemical characteristics of the water was produced by the tidal cycle and the mixing of water masses of different origin. These changes were highly significant both spatially and temporally, yet with varying effects on physical parameters, nutrients and the different components of SPM. Significant differences in nutrient concentrations were also observed when the data-set was divided into ebb and flood components, irrespective of the depth. Nitrate and nitrite rose to 1.8 times higher during the flood. Spatial differences of SPM were less marked than those of nutrients, only particulate organic carbon (POC) being significantly higher at the surface than in the intermediate and the lower layer. Both POC and pheopigment concentrations increased markedly through the water column, being highest shortly before the lower low tide. In contrast, suspended solid (SS) content increased sharply after the lower low tide (>40 mg l⁻¹) and this coincided with a marked decrease of the C/SS content (<20 mg g⁻¹). The lagtime between POC and SS tidal transport was caused by particle resuspension from the exposed intertidal sediments as the tidal level rose, and particle transport selection in relation to the tidal state. This revised version was published online in August 2006 with corrections to the Cover Date.     

Phytoplankton,sediment and optical observations in Netherlands coastal water in spring

Factors controlling the dynamics of suspended particulate matter (SPM), its influence on sea-leaving radiance and in-water optical properties, and the consequences of optical variation for phytoplankton growth, were studied at the ‘Processes of Vertical Exchange in Shelf Seas’ (PROVESS) project's southern North Sea site during April 1999. The optical properties of Netherlands coastal water were not unexpectedly found to be primarily determined by suspended sediment (Case 2) and were classified as Jerlov type 7 ‘relatively turbid coastal water’. During the study period, vertical mixing periodically resuspended optically active particles from the bed fluff layer throughout the water column and into the near-surface layer. These particles influenced sea surface radiance reflectance, and the red/green ratio of radiance reflectance, both of which can be observed by remote sensing. Linear relationships between sea surface radiance reflectance and SPM concentration were primarily determined by the inorganic fraction, as organic SPM varied little in concentration throughout the cruise period. The inorganic fraction was an important scatterer of light at all wavelengths, whereas the organic fraction displayed a greater tendency for light absorption at shorter wavelengths. Although the euphotic layer (depth of 1% surface irradiance) was only 8–10 m deep, vertical mixing ensured that phytoplankton throughout the water column (∼18 m) had access to PAR in excess of the estimated compensation illumination.Growth rates of microplankton (which includes pelagic microheterotrophs as well as phytoplankters) were calculated using an algorithm from the PROWQM model. These ranged from 0.1 to 0.3 d⁻¹, and implied loss rates of 3–25% which were mostly attributed to mesozooplankton grazing. Estimated oxygen production, however, was in near equilibrium with oxygen demand observed in dark bottles, and implied a significant oxygen demand due to detrital respiration and nitrification. This was estimated as 3–6 mmol O₂ m⁻³ d⁻¹.In an order of magnitude timescale analysis, vertical mixing was found to be the single most important factor controlling the dynamics of SPM under mixed or stratified conditions. For a mixed water column microplankton aggregation and fluff layer resuspension also had the potential to redistribute material in the water column several times per day, whilst under stratified conditions horizontal exchange and inorganic particle sinking were more important. Resuspended material in a stratified water column remained below the pycnocline and had little impact on the near-surface layer optics. Other factors varied in importance with the level of stratification, which was recognised as a significant factor in determining the dynamics of SPM in this region of freshwater influence (ROFI).     

Experimental Estimation of the Deposition Rate of Water Suspended Particulate Matter in the Mouth of the Don River and in Taganrog Bay

Oceanology - The influence of salinity and other controlling factors (concentration of suspended particulate matter (SPM), particulate organic material) on the sedimentation rate of pelitic and...     

基于Landsat 8影像的黄河口悬浮物质量浓度遥感反演

悬浮物质量浓度是黄河口海域重要的水质和水环境监测参数之一,直接影响着水面以下光场的分布,进而影响水体的初级生产力和水域生态环境。本文基于2011年6—7月和11—12月共计89组现场实测悬浮物质量浓度和光谱数据,分析了黄河口及其附近海域不同悬浮物质量浓度的水体光谱特征,尝试利用多种波段组合建立悬浮物质量浓度遥感反演算法。结果表明865 nm波段与波段比655 nm/560 nm组合形式算法反演结果最优,算法相关系数R²为0.95,平均相对误差为25.65%。将算法应用于2014—2016年共7景Landsat 8 OLI遥感影像,分析了不同年份黄河口悬浮物质量浓度的时空分布特征,黄河口海域悬浮物质量浓度分布总体呈现近岸高,离岸低的特点,不同时期悬浮物质量浓度量值上有显著变化。     

胶州湾中溶解态铝的初步研究

本文利用改进的铝-荧光镓(Al-LMG)荧光光度法测定了2001年夏季和秋季胶州湾水样中的痕量溶解态铝,分析了夏、秋季胶州湾内溶解态铝的分布及其影响因素,在此基础上讨论了胶州湾中悬浮颗粒物对溶解态铝的贡献,并进一步探讨了溶解态铝在研究水团运动中的作用。计算了河流输入、大气干、湿沉降向胶州湾中溶解态铝的输送,及湾内外交换对胶州湾内溶解态铝的影响和胶州湾铝的存留时间。     

Seasonal Dynamics of Biogeochemical Processes in the Water Column of the Northeastern Black Sea

Integrated studies on the hydrochemistry and water column rates of microbial processes in the eastern sector of the Black Sea along a standard 100-miles transect off Gelendzhik from the coast to the central part of the sea at water depths of 100–2170 m show that a series of warm winters and the absence of intense convective winter mixing resulted in a relatively low content of suspended particulate matter (SPM), particulate organic carbon (POC), and nutrients in the water column in March 2009. The relatively high SPM concentrations and the presence of isotopically light POC at the offshore station are indicative of the supply of terrigenous material from land and low contributions of phytoplanktonic organic matter to the composition of SPM. This may explain the low rates of biogeochemical processes in the water column near the coast. The surface layer at deep-water stations is dominated by isotopically heavy phytoplanktonic organic matter. This suggests that the supply of terrigenous material from land was insufficient in offshore deep-water areas. Therefore, warm winters and insufficient nutrient supply do not prevent photosynthesis in the photic layer of the deep-water zone, which generates organic substrates for heterotrophic aquatic communities. The results of isotopic analysis of POC, measurements of the rates biogeochemical processes, and the hydrochemical characteristics of the water column can be used to determine the nature and seasonal variability of the POC composition.     

黄、东海边界悬浮物输运量的卫星遥感估算

利用2002—2015年的中等分辨率成像光谱仪(Moderate Resolution Imaging Spectroradiometer, MODIS)第4波段反射率产品对黄、东海边界的悬浮物输运情况进行了分析, 同时利用黄、东海2003年现场实测的悬浮物含量数据和这期间准实时的MODIS影像数据, 建立了基于MODIS第4波段遥感反射率的悬浮物含量遥感反演模型。基于该模型, 反演黄、东海表层悬浮物浓度, 并计算悬浮物扩散面积。利用反演得到的表层悬浮物浓度和悬浮物浓度垂向预测模型, 获取垂直方向上的悬浮物浓度, 同时结合水深、扩散面积数据, 计算特定时刻水体中的悬浮物含量。利用插值方法获得整个输运过程中各时刻水体中的悬浮物的含量, 计算各个时刻悬浮物含量的总和作为悬浮物的输送量。对2002年10月至2003年4月黄海向东海的悬浮输送量进行估算, 估算结果为153Mt。     

Stable Isotopic Composition of Particulate Organic Carbon in the Caspian Sea

The data on the isotopic composition of particulate organic carbon (δ¹³C_POC) in the Caspian Sea water in summer–autumn 2008, 2010, 2012, and 2013 are discussed in the paper. These data allowed as to reveal the predominant genesis of organic carbon in suspended particulate matter of the active seawater layer (from 0 to 40 m). The δ¹³C_POC =–27‰ (PDB) and δ¹³C_POC =–20.5‰ (PDB) values were taken as the reference data for terrigenous and planktonogenic organic matter, respectively. Seasonal (early summer, late summer, and autumn) variations in the composition of suspended particulate matter in the active sea layer were revealed. A shift of δ¹³C_POC towards greater values was seen in autumn (with a slight outburst in the development (bloom) of phytoplankton) in comparison with summer (with large accumulations and an extraordinary phytoplankton bloom confined to the thermocline area). The seasonal dynamics of autochthonous and allochthonous components in the suspended particulate matter of the Middle and Southern Caspian Sea was studied with the use of data on the concentration of particulate matter and chlorophyll a, the phytoplankton biomass and the POC content.     

Distribution, partitioning and fluxes of dissolved and particulate organic C, N and P in the eastern North Pacific and Southern Oceans

Concurrent distributions of dissolved and suspended particulate organic carbon (DOC and POC_susp), nitrogen (DON and PON_susp) and phosphorus (DOP and POP_susp), and of suspended particulate inorganic phosphorus (PIP_susp), are presented for the open ocean water column. Samples were collected along a three-station transect from the upper continental slope to the abyssal plain in the eastern North Pacific and from a single station in the Southern Ocean. The elemental composition of surface sedimentary organic matter (SOM) was also measured at each location, and sinking particulate organic matter (POM_sink) was measured with moored sediment traps over a 110-d period at the abyssal site in the eastern North Pacific only. In addition to elemental compositions, C : N, C : P and N : P ratios were also calculated. Surface and deep ocean concentrations of dissolved organic matter (DOM) and inorganic nutrients between the two sites displayed distinct differences, although suspended POM (POM_susp) concentrations were similar. Concentrations of DOM and POM_susp displayed unique C, N and P distributions, with POM_susp concentrations generally about 1–2 orders of magnitude less than the corresponding DOM concentrations. These differences were likely influenced by different biogeochemical factors: whereas the dissolved constituents may have been influenced more by the physical regime of the study site, suspended particulate matter may have been controlled to a greater extent by biological and chemical alteration. Up to 80% of total particulate P in POM_susp, POM_sink and SOM consisted of PIP. For all organic matter pools measured, elemental ratios reveal that organic P is preferentially remineralized over organic C and organic N at both sites. Increases in C : P and N : P ratios with depth were also observed for DOM at both sites, suggesting that DOP is also preferentially degraded over C and N as a function of depth. A simple one-dimensional vertical eddy diffusion model was applied to estimate the contributions of dissolved and suspended particulate organic C, N and P fluxes from the upper mixed layer into the permanent thermocline. Estimated vertical DOM fluxes were 28–63% of the total organic matter fluxes; POM_susp and POM_sink fluxes were 8–20 and 28–52% of the total.     

Contribution a l'etude chimique du materiel dissous et particulaire de l'estuaire de la riviere rimouski

Temperature, pH, total alkalinity, dissolved oxygen, silicate, nitrate, phosphate and the Mn, Fe and Al contents of suspended particulate matter (SPM) were measured in the Rimouski River estuary as functions of chlorinity during the period May—September 1980.At any given time, total alkalinity (TA) is conservative within the estuary with respect to chlorinity. However, the total alkalinity (TA) of the freshwater is related to river flow. This is attributed to dilution of the river water with bicarbonate-poor rainwater.Generally, pH follows the same pattern observed for TA in freshwater. Dissolved oxygen is usually more concentrated in freshwater and decreases linearly with increasing chlorinity. Freshwater is always saturated or supersaturated with respect to O₂. Seasonal fluctuations are attributed to temperature variations.There is no evidence for removal of soluble silicate from the freshwater entering the sea. The concentration of silicate in the freshwater is strongly influenced by rainfall. Soil leaching, conditioned by high rainfall increases the concentration of soluble silicate in freshwater. Nitrate behaves similarly whereas phosphate is complicated by the presence of sewage.Analysis of the Mn, Fe and Al contained in the SPM indicates dilution of river-borne particles rich in Mn by others less rich in this element. A decrease in Mn content with increasing chlorinity and SPM concentration as well as increasing concentrations of SPM with increasing chlorinity indicate that the composition is controlled primarily by physical mixing of material from two sources rather than by chemical processes. Within the analytical precision the Fe/Al ratio does not vary with the chlorinity.     

Properties of coarse particles in suspended particulate matter of the North Yellow Sea during summer

Fine particles in seawater commonly form large porous aggregates. Aggregate density and settling velocity determine the behavior of this suspended particulate matter(SPM) within the water column.However, few studies of aggregate particles over a continental shelf have been undertaken. In our case study, properties of aggregate particles, including size and composition, over the continental shelf of the North Yellow Sea were investigated. During a scienti?c cruise in July 2016, in situ ef fective particle size distributions of SPM at 10 stations were measured, while temperature and turbidity measurements and samples of water were obtained from surface, middle, and bottom layers. Dispersed and inorganic particle size distributions were determined in the laboratory. The in situ SPM was divided into(1) small particles(<32 μm),(2) medium particles(32–256 μm) and(3) large particles(>256 μm). Large particles and medium particles dominated the total volume concentrations(VCs) of in situ SPM. After dispersion, the VCs of medium particles decreased to low values(<0.1 μL/L). The VCs of large particles in the surface and middle layers also decreased markedly, although they had higher peak values(0.1–1 μL/L). This suggests that almost all in situ medium particles and some large particles were aggregated, while other large particles were single particles. Correlation analysis showed that primary particles <32 μm in?uenced the formation of these aggregates. Microscopic examination revealed that these aggregates consisted of both organic and inorganic ?ne particles, while large particles were mucus-bound organic aggregates or individual plankton.The vertical distribution of coarser particles was clearly related to water strati?cation. Generally, medium aggregate particles were dominant in SPM of the bottom layer. A thermocline blocked resuspension of?ne material into upper layers, yielding low VCs of medium-sized aggregate particles in the surface layer.Abundant large biogenic particles were present in both surface and middle layers.     

莱州湾口弱层结水体中沉积物再悬浮特征及其水平、沉降通量研究

近海悬浮物在海水中的运移受诸多因素影响,其中由于径流输入导致的水体层化是不可忽视的因素之一,研究层结水体中沉积物受潮流、波浪影响的再悬浮特征有重要意义.2005年5月15日在黄河口西侧18海里处的莱州湾口设立了一个周日连续观测站,试图揭示弱层结水体中悬浮物的再悬浮特征及其水平、沉降通量.利用ADCP回声强度反演得到了高...     

悬浮泥沙在长江口铀非保守行为中的重要作用

利用高精度的电感耦合等离子体质谱仪对2014年1月长江口表层水中溶解铀浓度及其234U/238U比值、2013年3月长江口表层沉积物中各矿物组分的铀含量及其234U/238U比值进行了测定,研究了其空间分布特征和影响因素。结果表明:除了长江径流和海水之外,长江口还有其他的溶解铀来源。水体中过剩铀与悬浮颗粒物浓度呈现显著相关性（r2=0.96）。对长江口表层沉积物进行的序列提取实验进一步表明,水体中悬浮颗粒物或沉积物中可解吸态和碳酸钙结合态铀可以在河口区域释放进入水体,而铁锰氧化物和有机物结合铀比较稳定,不受河口区混合过程的影响。每千克颗粒物或沉积物能够释放约2 μmol颗粒态铀,使其转化为溶解态。然而,铁氢氧化物和细颗粒物的絮凝吸附作用也可使溶解铀同时从河口水体中清除。在低盐度区,铀的清除和添加过程速率相近,使溶解铀呈现暂时的"伪保守"现象:颗粒态释放的铀具有明显低的234U/238U比值,导致水体的234U/238U低于保守混合值。在中高盐度区域,溶解铀呈现明显的富集现象。但是由于水相和颗粒相中的铀交换,可释放颗粒态铀的234U/238U接近溶解铀的234U/238U比值,从而导致水体的234U/238U比值呈现出保守性。长江口颗粒物的铀释放通量为（3.48±0.41）×105 mol/a,约占输入的总颗粒态铀通量（1.80±0.17）×106 mol/a的19.3%。长江口输入东海的溶解铀总通量（河流溶解态铀与河口添加铀之和）为（2.68±0.13）×106 mol/a,约为世界河流入海铀通量的11.7%。     

Dissolved Aluminum in the Upper St. Lawrence Estuary

The concentrations of dissolved aluminum (Al) in the upper St. Lawrence Estuary were determined during periods of high and intermediate river-discharge. Laboratory experiments simulating estuarine processes were also conducted in order to examine possible mechanisms controlling the Al distribution. During the high river-discharge, the Al concentration at river end-member was 1.63 µM and decreased exponentially with increasing salinity. An almost complete removal of dissolved Al was observed in the low salinity area up to 10 with an intensive removal in the turbidity maximum zone. Principal mechanisms responsible for the Al removal inferred from the laboratory experiments were flocculation and adsorption onto suspended particulate matter (SPM). During the intermediate river-discharge, the Al concentration was 0.72 µM at the river end-member and again decreased with increasing salinity. However, the removal was less pronounced, being only about 25%. Good fits with model predictions and laboratory experiments suggest that principal removal mechanisms were authigenic aluminosilicate formation and adsorption onto SPM. In the upper St. Lawrence Estuary, Al distribution is controlled by a combination of three removal mechanisms: flocculation, authigenic aluminosilicate formation, and adsorption. Each mechanism can become a dominant factor depending on the concentration level and speciation of dissolved Al in the river water.     

Variability of suspended organic matter in the northwestern Black Sea

The peculiarities in the distribution pattern of the concentration of suspended organic matter (SOM) components were studied for the long-term period of 1979–1995. We have analyzed their seasonal, annual, and interannual variability in the surface water layer and in the photosynthetic water layer in the northwestern Black Sea. Four areas pertaining to different concentrations of SOM components were defined according to the effect of riverine discharge and of open sea water masses, i.e. western, northern, central, and eastern areas. We have found an increase in the concentrations of SOM components in the summer-autumn period in the late 1980s and early 1990s, with the highest values observed in 1992. The concentration of suspended organic carbon was estimated for the concentration of Chlorophyll a in the surface water layer. These calculations are based on the regression relationship between simultaneous measurements of these two parameters in situ. It was found that the seasonal interannual variability in the concentrations of SOM components was affected by the volume of riverine discharge, its run to the sea, and climatic shifts.