近60年来长江河口河势变化及其对水动力和盐水入侵的影响Ⅱ.水动力

本文基于本系列论文Ⅰ中数值化的长江河口20世纪50年代、70年代海图获得的岸线和水深资料,以及2012年水深实测资料,设置不同年代模式网格,考虑径流量、潮汐和风应力作用,建立长江河口水动力和盐水入侵三维数值模式,模拟和分析不同年代潮汐潮流、单宽余通量、分汊口水通量和分流比,及其河势变化对它们的影响。最大潮差在3个年代间的变化主要在北支区域,50年代至70年代,北支潮差减小,减小区域集中在北支中段,2012年相比70年代北支潮差增大。单宽水通量在50年代北港大于南港,北支下段向上游输运、上段量值较小,在70年代南港大于北港,北支下段量值较小、上段向下游,在2012年南北港水通量较为接近,北港稍大,整个北支水通量向上游。定量给出了50、70年代和2012年南北支、南北港大潮期间和小潮期间涨潮、落潮和净水量和分流比,结合河势变化分析了不同年代间的变化原因。     

长江口盐度的时空变化特征及其指示意义

2003年2,7月在长江口进行了枯、洪季大规模综合水文测验,布控范围西自江阴东至口外-20m,测验站点覆盖4条入海汊道.测验资料统计分析表明:(1)径流大小、汊道分流比、潮汐强弱和地形条件是控制盐度时空变化的主要要素;(2)在盐度空间分布上从大至小的顺序是:北支,南槽,北槽,北港口;(3)北支枯季发生盐水倒灌南支,而洪季可有一半以上区段为淡水所控;在其他3个入海汊道中,北港口门段是长江口盐淡水混合相对最弱的区段,盐度潮周期变幅最大,但洪枯变幅最小;南槽的盐淡水混合较强,盐度潮周期变幅较小,但洪枯变幅很大;北槽介于两者之间.(4)盐度时空变化反映洪季北支、南港和南槽分流比都有所增加.     

长江口崇明东滩及相邻区域地形演化与驱动因素分析

河口大型滩涂演化关系到航运通畅、生态保护以及近岸工程的安全性,是地貌学和工程界关注的热点。利用单波束测深系统对长江口崇明东滩进行高精度监测,并结合近年来周围环境因素分析其冲淤格局。结果表明:(1) 2011-2017年间崇明东滩和北港北沙基本以淤积为主,北港北汊河槽中央局部形成-2 m心滩,-5 m等深线包络面积基本稳定,整体呈"长高不长大"的格局;(2)海洋来沙是其淤积的主要物源,汊道涨落潮时空分异而形成的两大环流是塑造此地形的主要原因;崇明东滩和北港北沙的淤积直接挤压北港北汊的发展,沙体淤积可能会引起未来两大沙体的并靠;(3)崇明东滩、北支南沿的滩涂整治工程是促进北支萎缩和崇明东滩淤积的重要因素,另外横沙通道落潮分流增加,青草沙围水工程改变了北港河槽的曲率,也有利于北港北沙的淤积。     

Ecological performance indicators in the North Sea: development and application

Different signals of distress from the North Sea ecosystems started a discussion on the protection of the ecosystem at the third North Sea Ministers Conference in 1990. This was followed by a number of workshops on ecological indicators under the auspices of the North Sea Task Force and the Oslo and Paris Commissions (OSPAR). In 1997 the member countries around the North Sea agreed to develop and apply an ecosystem's approach in the management programs for both the North Sea fisheries and the marine environment. Following this agreement the identification of the ecological qualities objectives for the North Sea ecosystem started. Further work in this direction has lead to the setting up of various national projects geared towards creating a better understanding of the North Sea ecosystem.In the Netherlands, two departments (Water management and Nature and fisheries management) from the Ministry of Transport, Public works and Water Management (V&W) and the Ministry of Agriculture, Nature and Fisheries Management (LNV) agreed to integrate their policies for the management of the Netherlands section of the North Sea. The results from these projects (started in 1996) should enable the policy makers and managers to formulate policies that could lead to the creation of a balance between the effects of human activities and the preservation of the natural qualities of the North Sea ecosystem.One of the projects is strictly designed to develop ecological indicators for the Dutch part of the North Sea. These indicators are based on various monitoring data and related in one way or another with human activities. In this way it is possible to evaluate the effects of human impacts on the ecosystem. Long-term changes in the ecological performance of the ecosystem can be elucidated by the use of the ecological indicators. Thereby making it possible for the policy makers and the managers of the NCP to evaluate the effects of their policies and management recommendations on the quality of the ecosystem.This paper describes the process and the steps taken by the authorities in the countries around the North Sea to develop a set of ecological indicators for the management of the North Sea ecosystem. Focus will be made on the efforts made in the Netherlands to develop indicators that did provide the basis for the development of Water and Nature conservation policies and new management strategies for maintaining the sustainable use of the Dutch section of the North Sea.     

近60年来长江河口河势变化及其对水动力和盐水入侵的影响Ⅲ.盐水入侵

本文应用本系列论文Ⅱ中建立的长江河口水动力和盐水入侵三维数值模式,模拟长江河口20世纪50年代、70年代和2012年盐水入侵,定量分析不同年代河势下盐水入侵状况和变化程度及其原因。在北支,不同年代盐水入侵的变化是由分流比和潮差共同作用造成的。50年代北支盐水入侵较强,70年代大幅下降,中上段出现淡水,2012年盐水入侵极为严重,整个北支被高盐水占据,上段出现强烈的盐度锋面。50年代和2012年,北支盐水倒灌南支,大潮期间远大于小潮期间,2012年远强于50年代,70年代没有北支盐水倒灌南支现象。在南支,50年代、70年代南支大部分为盐度都小于0.45的淡水,在2012年大潮期间由于出现了强烈的北支盐水倒灌,南支上段出现盐度大于0.45的盐水。在南北港,在50年代盐水入侵最严重;大潮期间,北港净分流比南港大21.6%,北港盐度小于南港盐度,外海盐水主要通过南港入侵,出现南港盐水倒灌进入北港的现象。至70年代,南支主流转向南港,南港净分流比增大,比北港大10.4%,南港盐度明显小于北港盐度;南北港盐水入侵较弱。在2012年,南支主流再次转向北港,北港分流比比南港大10.4%,南港的盐水入侵再次强于北港。小潮期间,50年代由于南港分流比相比于大潮时更小,南港盐水上溯距离更远,上段盐度比更大;至70年代,北港分流比减少,盐水入侵减弱;至2012年,由于大潮时期北支倒灌的盐水在小潮期间到达北港,北港净盐通量比大潮时期大。由于潮动力减弱,小潮期间各年代垂向盐度分层更明显,盐水入侵变化与大潮期间一致。     

LONG-DISTANCE ATMOSPHERIC TRANSPORT OF DUST FROM CHINESE DESERT TO THE NORTH PACIFIC

The Chinese desert is one of the major sources of atmospheric mineral dust transported for a long distance to the North Pacific by the atmospheric circulation. The characteristic of the aerosol in the North Pacific is smilar to that of the aerosol in North China with a considerable concentration of mineral in spring due to the large-scale dust storm occurring in North China. The study of isotope tracer indicates that the concentration of Al is significantly related to 210Pb, suggesting that the mineral aerosol in the North Pacific may origir ate from the desert in Northwest China by using air mass trajectory analysis. About 6-12×106 tons of Chinese desert mineral dust per year would be transported to the North Pacific.     

Relationship between Composition of Settling Particles and Organic Carbon Flux in the Western North Pacific and the Japan Sea

Settling particles play an important role in transporting organic carbon from the surface to the deep ocean. It is known that major components of settling particles are biogenic silicates (opal), biogenic carbonate (CaCO₃), lithogenic clays and organic matter. Since each component aggregates and/or takes in organic carbon, all of these components have the ability to transport particulate organic carbon (POC) to the interior of the ocean. In this study, sediment trap experiments were carried out in four areas of the western North Pacific (including a marginal sea). Factors are proposed that correlate the composition of settling particles with POC flux. Annual mean organic carbon fluxes at 1 km depth in the western North Pacific Basin, Japan Sea, Hidaka Basin and northern Japan Trench were found to be 14.9, 18.1, 13.0 and 6.6 mg/m²/day, respectively. Organic carbon flux in the western North Pacific was greater than that in the Eastern North Pacific (7.4), the Equatorial Pacific (4.2), the Southern Ocean (5.8) and the Eastern North Atlantic (1.8). In the western North Pacific, it was calculated that 52% of POC was carried by opal particles. Opal is known to be a major component even in the Eastern North Pacific and the Southern Ocean, and the opal fluxes in these areas are similar to those in the western North Pacific. However, the organic carbon flux that was carried by opal particles (OC_opalflux) in the western North Pacific was greater than that in the Eastern North Pacific and the Southern Ocean. These results indicate that the ability of opal particles to transport POC to the deep ocean in the western North Pacific is greater than that in the other areas.     

华北5月降水年代际变化

针对华北5月降水的年代际变化特征和成因,用华北5月降水资料、NCEP大气环流资料以及海表温度（SST）资料,采用EOF分析、相关分析、合成分析等方法研究了华北5月降水以及相关海区SST的年代际变化;结果表明从60年代中期至90年代初期华北5月降水存在明显的年代际变化,1965～1981年华北5月降水偏少,1982～1992年华北5月降水偏多;西太平洋暖池相比热带中东太平洋、热带印度洋对华北5月降水年代际变化有更明显的影响;当西太平洋暖池异常发展,热带中东太平洋、热带印度洋海温年代际变化处于暖位相,东亚上空为反气旋性环流异常场,东亚大槽较弱,副热带高压偏强偏西时,华北5月降水偏多;反之,副热带高压偏弱偏东时,华北5月降水偏少.     

长江口滞流点洪、枯季移动的数值分析

为研究长江口滞流点位置的季节变化,利用Delft3D-Flow模块建立长江口二维潮流数学模型,通过实测水文资料对模型进行验证。在此基础上,模拟长江口各汊道洪、枯季滞流点移动情况,并从各汊道沿程断面的落潮量、涨潮量和落、涨潮量之比3个方面进行了水动力分析。结果显示:洪季,北支滞流点在八滧港东北方向约1.9 km处;在南支各汊道中,北港滞流点位于鸡骨礁东北方向约10.0 km处,北槽滞流点位于牛皮礁东南方向约3.8 km处,南槽滞流点位于大辑山东北方向约14.1 km处。枯季,除北槽外,其余各汊道均出现两个滞流点,且北支的两个滞流点相距最远,分别在灵甸港西南方向约3.2 km处和六滧港东北方向约3.1 km处;北港滞流点分别在鸡骨礁西北方向约25.8 km和20.2 km处,北槽滞流点在横沙以西约5.3 km处,南槽滞流点分别在中浚西北方向约6.5 km和东北方向约5.5 km处。北支洪、枯季滞流点的移动距离为4.6~53.3 km,北港、南槽洪、枯季滞流点的移动距离分别为22.0~27.7km和34.6~39.2 km,而北槽洪、枯季滞流点的移动距离最大,为57.1km。长江口各汊道滞流点的移动反映了河流径流和海洋潮流的综合作用。     

北黄海盆地区域地质特征

北黄海盆地位于黄海的北部，由于勘探程度低，研究投入少，使得它成为我国迄今为止尚未发现油气的惟一海区。随着我国在南黄海盆地和朝鲜在北黄海盆地东部发现油气，如何实现北黄海盆地油气突破，成为我们研究的焦点。结合该区现有资料和前人研究成果，对北黄海盆地的地球物理场和地质构造特征进行了全面的论述，并在此基础上，对该区油气资源远景作了初步评价。     

Kinetic Energy Variability in the North Indian Ocean Using a Numerical Model

The North Indian Ocean exhibits profound impact of variation in lower tropospheric winds. In the present study climatological monthly winds are used to force a nonlinear reduced gravity model of the North Indian Ocean to simulate climatological surface circulation and sea level anomaly for all 12 months of the year. The sea level anomalies agree reasonably well with satellite altimeter derived sea level anomalies. The model successfully simulates the varying eddy structure and current pattern of the North Indian Ocean. Finally, the kinetic energy variation in the North Indian Ocean with special reference to equatorial region and the boundaries is analyzed in detail.     

Kinetic Energy Variability in the North Indian Ocean Using a Numerical Model

The North Indian Ocean exhibits profound impact of variation in lower tropospheric winds. In the present study climatological monthly winds are used to force a nonlinear reduced gravity model of the North Indian Ocean to simulate climatological surface circulation and sea level anomaly for all 12 months of the year. The sea level anomalies agree reasonably well with satellite altimeter derived sea level anomalies. The model successfully simulates the varying eddy structure and current pattern of the North Indian Ocean. Finally, the kinetic energy variation in the North Indian Ocean with special reference to equatorial region and the boundaries is analyzed in detail.     

The Decline of the North Sea Whelk (Buccinum undatum L.) Between 1970 and 1990: A Natural or a Human-Induced Event?

Abstract. Recent surveys in the southern and central North Sea and the Dutch Wadden Sea revealed that the whelk Buccinun undarum L. can no longer be found in areas where whelks were abundant twenty or more years ago.
The decline of whelk populations tends to coincide with areas of various, intense human activities, which may cause either pollution or physical damage. Potential causes for the decline of whelks from the southern North Sea and coastal areas are discussed and considered in view of North Sea ecology and protective policies for the North Sea.     

Geotechnical characteristics of deep-sea sediments from the North Atlantic and North Pacific oceans

Geotechnical properties from a series of deep-sea sites in the North Atlantic and North Pacific oceans are examined to evaluate overall trends and to compare with similar fine-grained soils found on land. The study areas encompass a range of sedimentary environments dominated by combinations of turbidite and pelagic deposits. Carbonate content in excess of 20% is seen to result in a decrease in liquid limit and compressibility. Vertical profiles of geotechnical properties in the North Pacific show broader changes in down-core geotechnical properties compared to the North Atlantic and reflect the effects of long-term climatic changes and seafloor spreading. Sediments in the North Atlantic indicate significant differences depending on location, which is attributed to variability in turbidite deposition, water depth, distance from sediment sources, and the effects of bottom currents. Compared to equivalent fine-grained soils on land, deep-sea sediments are generally softer, more compressible and have higher friction angles at comparable Atterberg limits. Deeper and older sediments in the North Pacific are characterized by unusually large plastic limits, which are attributed to the presence of volcanic fractions. Empirical relationships for compression index and friction angle are discussed for sediments from both oceans.     

Changes in North Sea macrofauna communities and species distribution between 1986 and 2000

The North Sea Benthos Project 2000 was initiated as a follow-up to the 1986 ICES North Sea Benthos Survey with the major aim to identify changes in the macrofauna species distribution and community structure in the North Sea and their likely causes.The results showed that the large-scale spatial distribution of macrofauna communities in the North Sea hardly changed between 1986 and 2000, with the main divisions at the 50 m and 100 m depth contours. Water temperature and salinity as well as wave exposure, tidal stress and primary production were influential environmental factors on a large (North Sea-wide) spatial scale.The increase in abundance and regional changes in distribution of various species with a southern distribution in the North Sea in 2000 were largely associated with an increase in sea surface temperature, primary production and, thus, food supply. This can be most likely related to the North Sea hydro-climate change in the late 1980s influenced by the variability in the North Atlantic Oscillation (NAO). Only one cold-temperate species decreased in abundance in 2000 at most of the stations. Indications for newly established populations of offshore non-native species were not found.Differences in macrofauna community structure on localised spatial scales were predominantly found north of the 50 m depth contour off the British coast along the Flamborough Head Front towards the Dogger Bank, off the coast of Jutland and at the Frisian Front. These changes were most likely attributed to stronger frontal systems in 2000 caused by the increased inflow of Atlantic water masses in relation to the hydro-climate change in the late 1980s.     

长江口南北支二维氯度数学模型

枯水大潮期间，长江口北支向南支倒灌盐水，使南支河段和黄浦江水质恶化。，多年来这一问题为各界所重视。本文采用二维数学模型模拟了南北支水流和氯度的变化。数学模型经验证以后，计算了封堵北支方案，分析了工程前后含氯度变化情况。封堵北支后，切断了北支向南支倒灌盐水的来源，南支河段含氯度大幅度下降，数模计算反映了北支倒灌盐水在南支河段中的重要作用     

Concentration and toxic potential of polychlorinated biphenyl congeners in migratory oceanic birds from the North Pacific and the Southern Ocean

Concentrations of PCBs and their toxic potential were examined in subcutaneous fat of eight albatross and one petrel species collected from the North Pacific and the Southern Oceans. Among all the species analyzed, high PCB levels were found in adult male blackfooted albatross from the North Pacific with the mean value of 92 microg/g wet weight. No significant gender difference in PCB accumulation was observed (P>0.1). The mean PCB levels in Southern Oceanic birds were 1 or 2 orders of magnitude lower than those from the North Pacific albatrosses. A regional-specific accumulation of non-ortho coplanar congeners were observed, most birds from the Southern Ocean had higher IUPAC 169 levels while IUPAC 126 concentrations were higher in those from the North Pacific. The estimated toxic equivalents for black-footed and Laysan albatrosses from the North Pacific were in the same range of some fish-eating birds, which were highly contaminated by PCBs. The correlation between ratio of IUPAC 169/126 concentration and total PCBs concentration indicated the possibility of induction in cytochrome P450 activities in North Pacific albatrosses (P<0.01). The calculated hazard indices indicated that black-footed and Laysan albatrosses inhabiting in the North Pacific had similar threshold levels which were known to cause toxic effects in some populations of fish-eating birds.     

应用Argo资料分析西北太平洋冬、夏季水团

应用Argo剖面浮标观测的温、盐度资料,分析了西北太平洋海域冬、夏季的温、盐度分布、水团结构及其分布。首先采用T-S点聚图法分析了该海域水团分布的基本情况,由点聚分析结果可知,该海域至少存在6种以上水团;再用模糊聚类软化法对水团作进一步划分,分别计算了该海域6至11类水团的F和△F值,结果表明,冬、夏季的△F值都以划分为8类时为最大,这与大洋水团的稳定性是一致的,因此,该海域冬、夏季水团以划分为8类最佳,它们分别是北太平洋热带表层水、北太平洋次表层水、北太平洋中层水、北太平洋副热带模态水、北太平洋深层水和赤道表层水,以及南太平洋次表层水和南太平洋中层水。     

PDO的三维空间结构和时间演变特征

利用再分析次表层海温资料和CCSM3模式的1870-1999年130 a模拟试验的结果,分析了北太平洋年代际变化(PDO)的三维空间结构和时间演变特征.结果表明,CCSM3模式较好的模拟了北太平洋年代际变化的主要特征,对再分析资料和模式结果的分析都表明从北太平洋表层至次表层的中层,年代际变化是非常显著的,PDO不仅仅局...     

应用Argo资料分析西北太平洋冬、夏季水团

应用Argo剖面浮标观测的温、盐度资料,分析了西北太平洋海域冬、夏季的温、盐度分布、水团结构及其分布。首先采用T-S点聚图法分析了该海域水团分布的基本情况,由点聚分析结果可知,该海域至少存在6种以上水团;再用模糊聚类软化法对水团作进一步划分,分别计算了该海域6至11类水团的F和△F值,结果表明,冬、夏季的△F值都以划分为8类时为最大,这与大洋水团的稳定性是一致的,因此,该海域冬、夏季水团以划分为8类最佳,它们分别是北太平洋热带表层水、北太平洋次表层水、北太平洋中层水、北太平洋副热带模态水、北太平洋深层水和赤道表层水,以及南太平洋次表层水和南太平洋中层水。