不同潮时对厦门湾水体中234Th/238U不平衡的影响

厦门海水体中^234Th/^238U不平衡的时间序列数据表明，无论是溶解态、颗粒态^234Th还是总^234Th,相对于母体^238U均严重亏损，呈现出与开阔大洋水明显不同的特征。溶解态、颗粒态^234Th的停留时间介于0．5－41d之间，其中低潮时停留时间比高潮时小2－4倍，证实近岸海域具有强烈的清除、迁出作用，且潮汐变化对海域颗粒动力学特征有重要影响。^234Th停留时间与总悬浮颗粒物浓度（TSM）、Ch1.α的关系则表明，近岸海域元素的清除、迁出作用主要受陆源颗粒物输送的影响，与生物活动关系并不密切。此外，非稳态与稳态清除模型结果的对比证明，稳态模型对于具有强烈清除、迁出作用的近岸海域是适用的。     

厦门湾水体中铀、钍同位素及悬浮颗粒物的粒径谱--颗粒物采集方法的影响

运用增强型混合纤雏素(CN-CA)膜、聚碳酸酯膜和聚丙烯滤芯过滤3种不同的方法采集、研究厦门湾水体中悬浮颗粒物(SPM)及其U、Th同位素的粒径谱．发现3种方法所得SPM总浓度和U、Th各同位素的总比活度具有很好的一致性,但粒级分布存在差异．SPM的浓度随粒径的增大而增加,并且SPM的粒径谱控制着颗粒活性很强的4种钍同位素的拉径谱．对于所研究的3种方法,采用聚碳酸脂膜过滤是研究沿岸海域SPM及颗粒活性核素粒级分布比较理想的方法。     

江苏近岸高、低潮位变化规律探讨

利用MForeman改进的G·Godin潮汐调和分析及预报程序对江苏省辐射沙洲海域的16个验潮站潮位资料进行了调和分析和潮汐预报。根据各测潮站高、低潮位预报结果,对各站高低潮潮时差、低潮每日延迟时间、高潮每日延迟时间进行了统计计算,并对辐射沙洲海域高低潮潮时差特征值的分布进行了分析。利用潮汐表预报结果探讨了江苏沿岸6站的高潮位、低潮位、高低潮潮时差、高潮每日延迟时间、低潮每日延迟时间之间的对应关系,并分析给出了各量的变化周期。     

从234Th的固/液分配看海洋胶体的作用

1994—1995年期间,利用β计数法实测了南沙群岛海域、南海东北部海域、厦门湾塔角附近海域和九龙江河口区共计116份海水样品中溶解态与颗粒态234Th的放射性比活度。结果表明,颗粒态234Th占总34Th的份额大小顺序为：九龙江河口区＞厦门海塔角附近海域＞南沙海域。南海东北部海域。234Th的条件分配系数Kd介于1．1×104—20×106dm3／kg之间,平均为2．2×105dm3／kdKd与总悬浮颗粒物含量（7SAN呈负相关关系：lg（Kd）＝－0．59·lg（TSM）＋5．67,这一“颗粒物浓度效应”可归因于海洋胶体物质的存在。由上述关系获得4个研究海区胶体浓度与悬浮颗粒物浓度的函数关系：Cc＝f（TSM0．59）。     

南海北部海区非藻类颗粒物吸收系数的变化特性

在2003年10月广东沿岸航次和2004年9月南海北部开放航次数据的基础上,分析了南海北部水体非藻类颗粒物吸收系数(aNAP(λ))的变化。结果显示,沿岸水体的非藻类颗粒物吸收光谱斜率(SNAP)平均值为0.010 3nm-1(标准偏差=0.000 7 nm-1),随叶绿素a浓度的增大呈现出减小的趋势,南海北部开阔海域水体SNAP的平均值为0.009 0 nm-1(标准偏差=0.001 3 nm-1);沿岸水体受陆源性输入的影响较大,表层水体aNAP(440)随盐度的增大而减小,随总悬浮颗粒物(SPM)浓度的增大而增大,aNAP(440)/SPM平均为0.045 m2.g-1;南海北部开阔海域水体非藻类颗粒物的吸收明显偏小,表层水体的aNAP(440)与盐度存在较弱的线性相关,与SPM之间没有表现出明显的相关性,aNAP(440)与叶绿素a浓度之间存在一定的幂指数关系,表明外海水体浮游植物的降解是非藻类颗粒物的主要来源之一。     

^234Th作为海洋学中示踪剂的研究进展

^234Th是海洋中日、周、月时间尺度上和颗粒物运动有关的过程的良好示踪剂,常用于海洋碳循环最为重要的区域——真光层中颗粒物的循环,以及和生物中介有关的及一些相对较快发生的海洋过程的研究。^234Th对我们研究由CO2循环导致的全球变暖问题,了解各种元素和化合物在海洋中的分布行为和最终归宿,促进全球质量平衡归宿模型的构建,研究某海域的生物泵与初级和新生产力,促进我们对海洋的进一步了解并引导它健康可持续地为人类所利用等方面有着重要的意义。简要论述了。^234Th作为海洋学中示踪剂的原理和发展过程,比较了目前所使用的各种采样和测量方法,详细介绍了它在垂直通量、颗粒物循环、水平传输和沉积物动力学等方面的应用,并针对目前存在的问题和不足简要归纳了未来研究的方向。到目前为止,^234Th仍然是最快的自然颗粒物活性计时器,而样品处理、分辨率和处理量等方面的进步则推动了。^234Th在海洋学研究中更广泛的应用。开阔大洋中很多^234Th工作都是在JGOFS计划的支持下进行的,因此,^234Th应用的潜在前景可针对JGOFS计划未完成的问题而进行深入研究。     

不同时间尺度下长江口海域表层悬浮体浓度变化

长江入海泥沙是中国东部陆架海沉积物的主要来源之一。本文基于MODIS-Aqua卫星的遥感资料并结合实测悬浮体浓度,建立了基于颗粒物后向散射系数的悬浮体浓度的反演方法,获取了2002—2017年长江口海域的表层悬浮体浓度分布,并分析其在潮周期、季节内以及年际等不同时间尺度下的变化特征。结果表明,在潮周期内,长江口122.3°E以西海域表层悬浮体浓度大潮高于小潮,落潮大于涨潮,高潮大于低潮;在季节尺度内.6—8月表层悬浮体浓度逐渐增加。而122.3°E以东海域,则出现相反的情况;长江口122.3°E以西海域的夏季平均表层悬浮体浓度年际变化明显,主要受长江入海水沙量年际变化的影响。长江口122.3°E以东海域表层悬浮体浓度的年际变化几乎不受长江入海泥沙的影响。风向对悬浮体浓度的扩散具有显著的作用,南风有利于高浓度悬浮体向外海扩散,东风则抑制扩展。     

长江口及其邻近海域悬浮颗粒物浓度和粒径的时空变化特征

长江口是典型的高浊度河口,长江口及其邻近海域悬浮颗粒物（suspended particulate matter,SPM）浓度跨度大,泥沙过程活跃、复杂。2015年7月9-20日（洪季）和2016年3月7-19日（枯季）,使用OBS和LISST分别测定了该区域99个和89个站位的SPM浊度、光衰减系数、总体积浓度、平均粒径和粒径谱等参数;同时通过现场过滤测定了各站位表、中、底3层的SPM质量浓度以及典型站位SPM中颗粒有机碳（particulate organic carbon,POC）的δ13C、颗粒氮（particulate nitrogen,PN）的δ15N以及POC/PN摩尔比值。结果表明,浊度、光衰减系数、总体积浓度等3个参数均与SPM质量浓度显示出了显著的正相关关系。研究区域SPM平均粒径一般表层大于底层、枯季大于洪季;长江淡水端元输出的SPM粒径枯季也明显大于洪季。具有相似粒径谱特征的SPM可以通过测定δ13C和δ15N值来进一步区分其来源和组成。SPM质量浓度和总体积浓度等参数结合还可以计算SPM有效密度,用以了解研究区域SPM的沉降过程。结果表明两个季节SPM有效密度和粒径之间显示出了显著的负相关关系,说明枯季长江输出的SPM由于粒径大、密度小、沉降速度低,加之强烈的垂直混合和口门拦门沙附近的再悬浮,随着环流可能到达研究区域北部的最东端;而洪季长江输出的SPM由于粒径小、密度大、沉降速度高,在口门附近快速沉降。     

辽河口水盐分布的数值研究

采用有限体积方法的海洋数值模式(FVCOM),对辽河口潮汐及盐度进行数值模拟.结果表明:辽河口盐度锋面位于三道沟上游2 km至下游2 km范围内,在2009-05径流条件下高潮和低潮时刻盐度值分别为16～26和10～16;高潮期间河口底层盐度值大于表层,低潮期间盐度垂向变化不明显;三道沟附近高潮时刻盐度值在5,7和8月...     

不同潮时对厦门湾水体中234Th/238U不平衡的影响

厦门湾水体中2 3 4 Th 2 3 8U不平衡的时间序列数据表明 ,无论是溶解态、颗粒态2 3 4 Th还是总2 3 4 Th ,相对于母体2 3 8U均严重亏损 ,呈现出与开阔大洋水明显不同的特征。溶解态、颗粒态2 3 4 Th的停留时间介于 0 .5— 41d之间 ,其中低潮时停留时间比高潮时小 2— 4倍 ,证实近岸海域具有强烈的清除、迁出作用 ,且潮汐变化对海域颗粒动力学特征有重要影响。2 3 4 Th停留时间与总悬浮颗粒物浓度 (TSM)、Chl.a的关系则表明 ,近岸海域元素的清除、迁出作用主要受陆源颗粒物输送的影响 ,与生物活动关系并不密切。此外 ,非稳态与稳态清除模型结果的对比证明 ,稳态模型对于具有强烈清除、迁出作用的近岸海域是适用的     

厦门湾水体中234Th的垂直分布及其时间变异特征

１９９６年 ９～１０月在厦门湾上屿附近海域定点站连续６个航次测定了水柱中溶解态（ＤＴｈ）、颗粒态~(２３４)Ｔｈ（ＰＴｈ）和溶解态~２３８Ｕ,获得了~２３４Ｔｈ的时空分布图象。研究海域水柱中ＤＴｈ、ＰＴｈ和总~２３４Ｔｈ（ＴＴｈ）的放射性比度分别在０．８０～３．９５山／ｍ~３、１,９３～５．６５Ｂｑ／ ｍ~３和 ３．４７～９． １８Ｂｑ／ｍ~３之间,整个水柱中 ＤＴｈ、ＰＴｈ和ＴＴｈ均与~(２３８)Ｕ呈不平衡,其特征是~(２３４)Ｔｈ亏损,且亏损程度明显大于大洋水体。颗粒态~(２３４)Ｔｈ和总悬浮颗粒物（ＴＳＭ）在水体中的分布及其随时间的变化趋势相当一致,非生物过程可能对近岸海域水体中~(２３４)Ｔｈ的分布起着非常重要的作用。     

杭州湾潮汐特征时空变化及原因分析

杭州湾是世界著名的强潮河口湾,一直是研究的热点。基于杭州湾口内外实测潮汐资料,对杭州湾潮汐特征及时空变化进行了系统分析,包括高潮位、低潮位、平均潮位、潮差、涨潮历时以及天文潮变化,同时分析了20世纪80年代以来潮汐特征变化的原因。结果表明:最近50年来,杭州湾年平均高潮位和海平面抬高,潮差增大;澉浦年平均低潮位抬高,涨潮历时缩短,浅海分潮增大;钱塘江河口治江缩窄是造成杭州湾潮汐变化的主要因素;浙江和邻近海域的涉海工程可能是造成浙江沿海海平面上升的主要原因之一。     

胶州湾的潮汐与潮流

胶州湾是我国沿海的一个重要港湾,长期以来对其进行了较多的调查研究工作。大港验潮站自1926年起开始观测(1936-1946年曾中断),目前已积累了44年的长期水位资料。山角底验潮站自1967年开始观测,也积累了16年的水位资料。我们还系统地搜集了我所1958-1959年在薛家岛、东洋嘴、团岛、麦岛、大公岛分别进行的四个月、两个月及半个月的观测资料,以及山东海洋学院1975年在红岛船厂(阴岛)、黄岛客运码头分别进行的三个月及两个月的水位观测资料和团岛湾、后岔湾、大石头等地的潮汐调和常数。此外,我们还搜集了胶州湾及其附近海区共二十三个测站的海流连续观测资料,其中十九个站的资料是由我所在1957-1959年观测的,三个站是1982年“全国海岸带调查”中测得的,另一个站是华东水利学院提供的资料。这些测站,除六个站为一昼夜连续观测外,其余十七个站均为二昼夜以上连续观测(有一个站为十五昼夜连续观测)。观测站位见图1。 我们把搜集到的这些潮汐、潮流资料进行了调和分析,得到了各主要分潮的调和常数及潮汐、潮流特征值。本文以此为基础,结合实测资料,分析了胶州湾潮汐、潮流的基本特征。     

Factors influencing nutrient dynamics in the eutrophic Jiaozhou Bay, North China

We conducted studies of nutrients and water mass movements in a semi-enclosed bay in northern China to understand nutrient dynamics under varying tidal regimes. Four cruises were conducted under varying tidal regimes in Jiaozhou Bay, two at neap tide and one at spring tide in August and one at spring tide in October 2001. In addition to transect surveys, drift experiments and an anchor station were employed to show current and tidal effects. Samples for nutrient evaluation were taken from the five major tributary rivers in March (dry season) and August (flood season) of 2002 to estimate nutrient transport by rivers, and wastewater samples were collected to evaluate nutrients in wastewater discharge. Benthic nutrient fluxes were determined by (1) incubation of sediments with overlying seawater on board the boat and (2) calculated by Fick’s First Law from nutrient pore water profiles. Nutrient concentrations were high in the north, especially the northeast and northwest sectors, reflecting human activities. Jiaozhou Bay was characterized by high nitrogen, but low phosphorus and silica concentrations compared to Chinese coastal seas. Based on nutrient atomic ratios, the limiting elements for phytoplankton growth in Jiaozhou Bay were silica and phosphorus. The fluxes of nutrients between sediment and overlying water varied depending on the specific nutrient, the site and redox conditions. Benthic nutrient fluxes based on sediment incubations were all lower than the estimated diffusive fluxes, implying that the nutrients released from sediment pore waters were probably utilized by benthic microalgal and bottom-water primary production. A preliminary estimate of nutrient budgets demonstrated that riverine and wastewater inputs were greater than atmospheric deposition into Jiaozhou Bay, except that nitrate from wastewater inputs was less than atmospheric deposition. Concentrations of nitrogen and phosphorus increased while silica decreased in the last four decades, similar to other eutrophicated estuaries. The resulting shift in nutrient composition in Jiaozhou Bay affects phytoplankton composition, trophic interactions, and sustainability of living resources.     

Suspended sediment dynamics on a seasonal scale in the Mandovi and Zuari estuaries,central west coast of India

Suspended particulate matter (SPM) collected at regular stations from the Mandovi and Zuari estuaries indicates that the peaks of high SPM coincide with peaks of high rainfall and low salinity and also with peaks of moderate/low rainfall coupled with high salinity during the monsoon. The estuarine turbidity maximum (ETM) is a characteristic feature, it occurs in the channel accompanying spring tide during the monsoon and pre-monsoon, and shifts to the bay on neap tide during post-monsoon. ETM remains at the same position in the Mandovi River, both during the monsoon and pre-monsoon, whereas in Zuari it stretched upstream during monsoon and migrates seaward of the channel during pre-monsoon. The ETM coincides with the freshwater–seawater interface during the monsoon and is formed by the interaction between tidal currents and river flows. The ETM during pre-monsoon is associated with high salinities and is generated by tidal and wind-induced currents. The turbidity maximum on neap tide during post-monsoon may be due to the erosion and resuspension of sediments from the emergent tidal flats and transport of these turbid waters into the bay. Funneling effect of the narrowing bay in the Zuari estuary and associated physical processes effectively enhance the magnitude of the currents and transports sediments to the channel. SPM retention percentage indicates that the estuarine channel is prone to siltation.     

厦门海域分粒级叶绿素a含量的分布特征

据2002年12月至2004年2月间厦门海域6个航次分粒级叶绿素a含量的调 查资料,研究了该海域分粒级浮游植物叶绿素a含量的分布特征及其控制因子．结果 表明:厦门海域叶绿素a含量平均值为5．36mg／m3,各调查月份中,8月份的含量最 高(13．6mg／m3),5月的次之(5．33mg／m3),12、2月的含量较低．叶绿素a含量的水 平分布在冬季时较为均匀;春、夏季在宝珠屿海域出现最高值(33．28mg／m3),九龙江 口外出现次高值(13．84mg／m3)．厦门海域全年以微型浮游植物占优势,小型浮游植 物在夏季高生物量时占比较高(41．O％),微微型浮游植物所占比例较小(年平均值 为9．7％)．冬季低温是浮游植物生长的主要限制因子,春、夏季随着温度升高,营养 盐的缺乏限制了浮游植物的生长．     

Methane sources,sinks and fluxes in a temperate tidal Lagoon: The Arcachon lagoon (SW France)

The Arcachon lagoon is a 156 km² temperate mesotidal lagoon dominated by tidal flats (66% of the surface area). The methane (CH₄) sources, sinks and fluxes were estimated from water and pore water concentrations, from chamber flux measurements at the sediment–air (low tide), sediment–water and water–air (high tide) interfaces, and from potential oxidation and production rate measurements in sediments. CH₄ concentrations in waters were maximal (500–1000 nmol l⁻¹) in river waters and in tidal creeks at low tide, and minimal in the lagoon at high tide (<50 nmol l⁻¹). The major CH₄ sources are continental waters and the tidal pumping of sediment pore waters at low tide. Methanogenesis occurred in the tidal flat sediments, in which pore water concentrations were relatively high (2.5–8.0 μmol l⁻¹). Nevertheless, the sediment was a minor CH₄ source for the water column and the atmosphere because of a high degree of anaerobic and aerobic CH₄ oxidation in sediments. Atmospheric CH₄ fluxes at high and low tide were low compared to freshwater wetlands. Temperate tidal lagoons appear to be very minor contributor of CH₄ to global atmosphere and to open ocean.     

福建沿海文昌鱼的分布及其资源保护对策

采用现场采样方法对福建沿海文昌鱼(Branchiostoma balcheri)的分布和资源状况进行了调查,为文昌鱼的保护提供依据。全省19个海区潮间带均未捕获文昌鱼;12个海区的潮下带浅海定量调查中,仅5个海区采集到文昌鱼。东山湾海区文昌鱼密度最高,为41.67尾/m2,其次是厦门十八线海区,为14.5尾/m2,厦门南线海区和黄厝海区分别为5.39尾/m2和4.71尾/m2,泉州大港海区仅捕到1尾,闽江口3个海区均未捕获。所获文昌鱼年龄大多为1龄,占39.2%,2龄占23.5%,3龄占25.5%,其他(1龄以下、4龄、5龄及以上)占11.8%。与20多年前的历史资料相比,文昌鱼的分布区大为缩小,资源量大为降低,资源已濒临枯竭。必须加大对文昌鱼资源的保护力度,有必要增设文昌鱼自然保护区,并加强对文昌鱼保护区的管理。     

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.