黄海溶解氧垂直分布的最大值

海洋溶解氧垂直分布中的最大值,正如最小值一样,亦为溶解氧垂直分布中的一个突出的现象.对于这一现象,不同的研究者作出了不同的解释.Thompson在太平洋北部及东北部25-50M处观测到氧最大值层,他们认为这一氧最大值层,是与光合带相适应的.对鄂霍次克海中氧的最大值的形成,绘出了一个假设的图,认为夏季氧垂直分布中的最大值,是由于在跃层形成时期,浮游植物光合作用时,大量的氧从上面渗入到稍下的层内,随着增温时该处稳定密度层的形成,垂直交换困难,因而氧即被保持下耒,形成了夏季最大值.Ichiye认为,密度跃层中的氧最大值,是由于氧的涡动扩散,要进行得比热的涡动传导为慢的缘故.     

长江口及其邻近海域溶解氧的分布变化

海水中的溶解氧与水体中动植物的生长有着密切关系(陈国珍,1961)。溶解氧和氧饱和度的资料对估计水体生产力和评价水体的有机污染状况具有重要意义。 本调查海区位于30°20''-32°00′N,124°00′E以西至长江口及其沿岸,地貌和水动力学均较为复杂。长江等水系终年输人淡水,在丰水期几乎影响到整个调査海区;东海沿岸流和合湾暖流的侵入导致调查海区溶解氧的分布变化较为复杂。我们于1985年8,11月和1986年1，5月对该海区进行了包括溶解氧在内的综合调查。共设6个断面50个调查站(图1),分层采样,沿用 Winkler法进行溶解氧测定,结合同期水文、生物调查资料,研究了溶解氧的分布特征。     

An ecological-physical coupled model applied to Station Papa

A vertical one-dimensional ecosystem model was constructed and applied to Station Papa. The model has seven compartments (phytoplankton, nitrate, ammonium, zooplankton, particulate organic matters, dissolved organic matters, dissolved oxygen) and was coupled with a mixed layer model for calculating diffusion coefficient which appears in the governing equations. The mixed layer model was driven by SST, SSS data observed at Station Papa in 1980 and ECMWF wind data for 1980, and the ecosystem model was driven by fixing nitrate concentration in deep layer to an observational value. The phytoplankton maximum in March was reproduced by the model although the maximum in fall-winter could not be reproduced. The model also suggests the importance of studying nitrification. As a whole, the model could reproduce characteristic features at Station Papa such as the summer ammonium maximum at 50 m depth, the summer dissolved oxygen maximum at 70 m depth and the absence of remarkable phytoplankton bloom.     

黄海溶解氧垂直分布最大值的成因

本文对黄海溶解氧垂直分布中最大值的成因进行了探讨．认为：浮游植物春花期光合作用产生的大量氧，是溶解氧垂直分布最大值得以在春季（5月）形成的基础；而良好的温、密跃层的存在是氧最大值得以形成的必要条件，夏季叶绿素最大值层中较强的光合作用，是氧最大值在夏季得以维持甚至增强的主要原因．提出：黄海春、夏季溶解氧垂直分布中的最大值并非主要由冬季保持而来．     

东沙群岛西南冷涡的海水理化特性

东沙群岛西南海区的溶解氧、活性磷酸盐和活性硅酸盐100m层四季的平面等值线出现封闭或半封闭的分布,表明了该海域气旋型涡旋的终年存在,溶解氧饱和度的断面分布也证实了东沙群岛西南海域终年存在下层海水抬升,并表明冷涡轴随深度增加而向东南方向倾斜。温度、盐度、溶解氧.活性磷酸盐在表层都有一均匀层,次表层有一跃层,而深层值则季节变化不大。     

烟台-威海北部海洋牧场底层溶解氧浓度的季节变化研究

基于2021年4~12月山东半岛烟台-威海北部海洋牧场区域4处连续观测站的长期观测数据, 研究了该海域底层溶解氧(dissolved oxygen, DO)浓度的季节变化特征, 并探讨了物理机制。该海域底层DO从春季到夏季逐渐降低, 而从夏季到秋季逐渐升高, 主要受温度控制; 各观测站DO均在8月达到最低值, 受垂向层结增强和底层生物化学耗氧增多的共同影响。底层DO浓度在东西方向差异较小, 而在南北方向上差异明显; 在春季和秋季DO浓度南高北低, 是由于层结较弱, 海水垂向混合向底层提供DO, 且南边水深更浅, DO更容易达到饱和或过饱和状态, 而水深更深处DO仍处于不饱和状态; 夏季DO浓度南边大于北边是季节性层结强度的空间差异所致, 同时南边底层DO浓度下降更快, 使其南北差异在夏季有所减小。在11月中旬, 近岸3个观测站底层DO快速增多, 可能是由于此前的大风过程引起浮游植物繁殖, 晴朗天气促进其光合作用使海水中DO增多, 之后海水层结消失, 海水充分垂向混合使丰富的DO到达底层。     

刘公岛海洋牧场底层海水溶解氧浓度的变化特征

由于缺乏长期观测资料,前人对山东半岛邻近海域海水溶解氧的时间变化和空间分布特征的研究较少。本文基于威海刘公岛海洋牧场于2016年7月20日至2017年3月14日期间,利用生态环境实时在线观测系统获得的底层海水的温度、盐度、水深、溶解氧数据,分析了该牧场海水溶解氧浓度的时间变化特征及其影响因素,并探讨了低氧灾害发生的可能性。结果表明在观测期间,该牧场海水溶解氧浓度以季节变化为主,冬季最大、夏季最小,其中2月份平均值最高,约为10.86mg/L,8月份平均值最低,约为5.91mg/L。同时海水溶解氧浓度也存在显著的小时变化和日变化,且变化幅度于8月份最大、3月份最小。影响海水溶解氧浓度变化的主要因素是海水温度,溶解氧浓度随着温度的季节性变化而变化。夏季,水体分层会使溶解氧浓度发生大幅度的降低,大风过程对于溶解氧浓度也有一定的影响,通过打破夏季的季节性温跃层使水体发生垂向混合从而为海底提供氧气,但大风过程之后的几天会出现溶解氧浓度降低的现象。本次研究发现刘公岛海洋牧场在观测期间不存在低氧现象。     

基于ADCP回声的黑潮-亲潮混合区浮游动物昼夜垂直迁移研究

利用深海潜标所搭载的声学多普勒流速剖面仪(acoustic doppler current profiler,ADCP)得到的后向散射强度Sv,研究了黑潮-亲潮混合区浮游动物的垂向分布、其昼夜垂直迁移(diel vertical migration;DVM)的基本特征、多时间尺度变化及对反气旋式中尺度暖涡的响应.结果表...     

黄河口区及其附近海域溶解氧的分布变化

本文讨论了1984年5月、8月、11月调查的黄河口区溶解氧的分布。黄河口区溶解氧的分布主要受水温的影响,在春季还受硅藻的影响,而夏季受微型浮游植物的影响。 夏季,黄河口门底层水的表观耗氧量高达2.04ml╱L。反映了黄河悬浮物所携带的有机物氧化的结果。     

胶州湾东北部养殖海域夏季营养盐分布特征及其对浮游植物生长的影响

以2000年夏季胶州湾东北部养殖海域(女姑山)的现场调查为基础,结合前3年的调查结果和相关的历史资料,对该海域夏季营养盐含量分布特征及其对浮游植物生长的可能限制因子进行了分析和探讨。研究结果表明,胶州湾东北部典型养殖海域夏季表层水体各种营养盐含量高于胶州湾全湾夏季及全年的平均值,铵氮是总溶解态无机氮的主要组成形态,硝态氮次之。该海域的环境因素适宜浮游植物的生长,相关分析显示:叶绿素a与pH及DO呈显著正相关,与PO4、SiO3、NH4、DIN呈负相关。通过分析营养盐对浮游植物生长的限制因素发现,该海域各种营养盐含量相对较高,无机氮不会成为浮游植物生长的限制因素,磷酸盐有限制的可能性,而浮游植物生长受控于硅酸盐的几率最大。     

The Influence of Physical Factors on the Variation of Phytoplankton and Nutrients in the Bohai Sea

The cycle of the phytoplankton in a coastal water is controlled by the biological processes, solar radiation, water temperature and physical transport processes. A three-dimensional ecosystem dynamic model is adopted in this study to investigate the influence of different physical factors on the variation of phytoplankton and nutrients in the Bohai Sea. The simulation is carried out for the year 1982. The simulated annual cycle of the primary production and nutrients are in reasonable agreement with the observations in the pattern. Vertical mixing can both affect the vertical transportation of nutrients and horizontal distribution of primary production. In winter the vertical distribution of nutrients is homogeneous because of the intensive mixing, while in summer there is a high value of nutrients in the depth about 15 m due to the stratification. The high primary production plague and the weak mixing center is positional correspondence. The production of phytoplankton is sensitive to the photosynthetically active radiation, which is strongly influenced by the transparency. The increase of the transparency can promote the production in spring and autumn significantly, but has little effect on the production in summer. The change of the transparency can both affect the occurrence time and the amplitude of the phytoplankton bloom dramatically. Horizontal advection does not affect the variation trend of the annual cycle of chlorophyll-a, but does affect the relative magnitude of the phytoplankton bloom, especially in summer. Horizontal advection can dramatically alter the horizontal distribution of chlorophyll-a. The maximum concentration of chlorophyll-a without horizontal advection in summer is twice as high than that with advection and the high chlorophyll-a areas locate along the coast. The river discharge only has regional influence on the ecosystem. The Huanghe River with high nitrate concentration influ-ences the annual cycle of nitrogen of the Laizhou Bay significantly.     

千岛湖水温垂直分层的空间分布及其影响因素

湖泊热力分层及热力循环深刻影响深水湖泊生态系统。随着全球气候变暖,湖泊热力过程会发生显著变化。作为深水水库型湖泊,千岛湖的热力过程与水环境的变化紧密相连,为了分析千岛湖水体水温、湖泊热力分层参数(温跃层深度、厚度和强度)的分布,探讨温跃层深度与水温、水体透明度以及水深之间的关系,本文根据2014年7月份与2015年5月份对千岛湖全湖60个采样点的水体理化指标的垂向分布调查数据,计算得到千岛湖热力分层参数,进而分析其时空分布特征及主要影响因素。结果表明,千岛湖水体水温垂直分布呈现正温分布,春夏季全湖范围内均存在不同程度的温度分层现象,温跃层深度、厚度和强度均从上游河口向下游敞水区逐步增大,这种空间变化的趋势在7月份比5月份更显著。水温、透明度和水深是影响温跃层深度的主要因素。夏季湖泊热力分层稳定期温跃层深度与表层水温(0—2m)存在显著负相关关系,与透明度和水深存在正相关关系。     

厦门港叶绿素的时空分布及其与水环境因子关系的多元分析

叶绿素(Chl)是水体初级生产的重要指标,随环境因素变化而波动,因此,周年持续的原位实时监测可以更准确地反映水体初级生产水平及受控因素.作者于2017年全年通过水质自动在线监测对厦门港海域的叶绿素及水温、溶解氧、pH、盐度等水环境因子进行了实时监测分析,并基于多元分析研究了叶绿素含量时空分布与主要水环境因子之间的相关性...     

胶州湾小型底栖生物的丰度和生物量

1995年 5月— 1 996年 1月 ,在胶州湾北部软底水域进行每 2月一次的调查。结果表明 ,小型底栖生物的年平均丰度为 1 .51× 1 0 6ind/m2 ,最高值出现在 95B1和 95B2站 ,分别为 2 .73× 1 0 6 和 2 .75× 1 0 6ind/m2 ,最低值出现在 95B3站 ,数量为 0 .46× 1 0 6ind/m2 。小型底栖生物的年平均生物量为 1 .32 g/m2 (干重 )。皮尔逊相关分析表明 ,小型生物的数量与以碳和氮表示的浮游植物的生物量呈负相关 ,相关系数分别为 - 0 .969和 - 0 .947(P <0 .0 5)。共鉴定出 1 4个小型生物类群。自由生活的海洋线虫占总数量的 86.6% ,底栖桡足类居第 2位 ,占总数量的 5.7%。按生物量 ,海洋线虫 (35.9% )、介形类 (32 .6% )、多毛类 (1 3.7% )和桡足类 (8.3% )共同构成小型动物的优势类群 ,80 %以上的小型生物分布在 0— 2cm以浅表层内。与国内外同类研究结果进行了比较 ,并对小型生物在胶州湾生态系中的作用进行了探讨     

Distribution of dissolved oxygen and causes of maximum concentration in the Bering Sea in July 2010

According to data obtained in the Bering Sea during the 4th Chinese National Arctic Research Expedition, the distribution of dissolved oxygen(DO) was studied, causes of its maximum concentration were discussed, and the relationships between DO and other parameters, such as salinity, temperature, and chlorophyll a were analyzed. The results showed DO concentration ranged from 0.53 to 12.05 mg/L in the Bering Sea basin. The upper waters contained high concentrations and the maximum occurred at the depth range from 20 to 50 m. The DO concentration decreased rapidly when the depth was deeper than 200 m and reached the minimum at the depth range from 500 to 1 000 m, and then increased slowly with the depth increasing but still kept at a low level. On the shelf, the DO concentration ranged from 6.53 to 16.63 mg/L with a mean value of 10.75 mg/L, and showed a characteristic of decreasing from north to south. The DO concentration was higher in the area between the Bering Sea and Lawrence Island and was lower in the southeast and southwest of Lawrence Island at the latitude of 62°N. The formation of maximum DO concentration was concerned with phytoplankton photosynthesis and formation of the themocline. To the south of Sta. B07 in the Bering Sea basin, the oxygen produced by photosynthesis permeated to the deeper water and the themocline made it difficult to exchange vertically, and to the north of Sta. B07, the maximum DO concentration occurred above the themocline due to phytoplankton activities. On the shelf, the oxygen produced by phytoplankton photosynthesis gathered at the bottom of the thermocline and formed the DO maximum concentration. In the Bering Sea basin, the DO and salinity showed a weak negative correlation(r=0.40) when the salinity was lower than 33.1, a significant negative correlation(r=0.92) when the salinity ranged from 33.1 to 33.7, and an irregular reversed parabola(r=0.95) when the salinity was greater than 33.7.     

安邦河湿地浮游植物数量与环境因子相关性研究

2005年7月-2006年5月,对安邦河湿地浮游植物数量及其环境因子监测,运用相关分析和灰关联分析对其浮游植物数量与环境因子关系进行研究.相关分析结果显示,浮游植物数量与水温呈显著正相关(p<0.01);与DIN在春季呈显著正相关(p<0.01),在夏、秋季呈显著负相关(p<0.05,p<0.01);与DIP在各个季节均呈显著正相关(p<0.01,p<0.05);与溶解氧呈正相关,在春季和秋季相关显著(p<0.05,p<0.01),在夏季相关不显著(p>0.05);与透明度呈正相关,但相关均不显著(p>0.05);与pH值呈负相关,且在春季、夏季呈显著相关(p<0.01);灰关联分析结果表明,对安邦河湿地浮游植物数量影响最大的DIP,因此控制外源性的DIP的输入对于维持安邦河湿地生态系统的健康是非常重要的.     

Hypoxia in a pristine stratified estuary (Krka, Adriatic Sea)

The occurrence of hypoxia in October 1988 in the Krka estuary is described, with special reference to the Prokljan Lake. Hypoxia develops near the bottom in autumn in response to the temperature maximum that appears this time of the year. The decomposition rate of naturally present organic matter increases, creating higher biological oxygen demand. As the water column is stratified by salinity and temperature, mixing of seawater near the bottom with oxygen-supersaturated water which resides closer to the surface is very slow. When an extensive marine phytoplankton bloom appears below the halocline in the Prokljan Lake, then, because of the sinking and degradation of phytoplankton near the bottom, the dissolved oxygen concentration decreases further. The hypoxia becomes so severe that it causes massive mortality of benthic macrofauna. The decomposition of the macrofauna further decreases the dissolved oxygen concentration. The hypoxia may persist until an increase in the freshwater inflow occurs, which forces the arrival of colder marine water near the bottom via a compensating flow. In the absence of autumn rains, the hypoxia may be recorded throughout winter.     

渤海无机氮的分布

各种无机氮是浮游植物的基本营养物质，其含量多寡直接影响着海洋初级生产者的数量。在天然海水中，氮含量一般较低，因而在一定程度上它们常是浮游植物的限制因素之一。 渤海水产资源丰富，是我国重要渔场之一，因此对其生原要素的研究实属必要。为配合该水域水产生产农牧化的研究，本文根据多年(1959, 1960, 1983)的资料，通过讨论无机氮含量分布、百分组成及N/P 比值的变化特征，对该水域氮素生物环境作了评价。     

Distribution of marine lipid classes in salty Rogoznica Lake (Croatia)

Lipid classes in a small, eutrophicated salty lake (Rogoznica Lake, middle Adriatic), which is often subject to appeareance of anoxic conditions, were analyzed at the end of winter (March) and in summer (July) 2008. The results are supported with DOC, POC, phytoplankton, temperature, salinity and oxygen data. During both March and July massive, diatom blooms were recorded with maximum values at 5 m depth. Total lipids were found at high concentrations that were similar for the samplings in two months. Total particulate lipids dominated the pool, and showed large variations from 46.37 to 369.88 μg/l, with the highest concentration observed in the bottom anoxic layer in March. The variations for dissolved lipids were smaller and ranged from 44.82 to 124.35 μg/l. Opposite to lipids, DOC values increased 1.5 times between the two samplings, from the value of average 0.95 mg C/l in March to the average value of 1.44 mg/l in July. Conformingly with diatom blooms, POC was found in July at high concentrations (0.28–1.50 mg C/l), contributing to total organic carbon up to 46%. The distribution of organic carbon and lipids showed the tendency of accumulation toward deeper layers. The characterization of individual lipid classes revealed the dominance of phospholipids, indicating that the lipids in the lake mainly originated from the photosynthetically active phytoplankton community, which is sustained by high production of oxygen (oxygen saturation up to 200%). Low contribution of neutral lipids in the particulate fraction points to high availability of nutrients for present phytoplankton community. Lipid breakdown indices were found at significantly higher concentrations in March compared to July. Sea surface microlayer, the hydrophobic boundary, appeared to be generally lipid depleted in comparison to the sub-surface water. Qualitative analysis of sulfolipids revealed the potential of the lake for the occurrence of chemical interaction of sulfur with present organic matter.     

2011年春、夏季黄、东海水团与水文结构分布特征

根据2011年春季(4月)夏季(8月)两个航次调查的CTD温盐资料,获得观测期间黄、东海主要水团特征:(1)夏季黄海冷水团10℃等温线在黄海海域中部30m以深,影响范围西至122°E南至34°N,最低温度为6.2℃,比气候态平均冷水团温度低约2℃;(2)夏季冲淡水以长江口为中心,呈半圆形向外扩展,并无明显NE转向,30.00等盐线在32°N断面上东至124°E,南至29.5°N,扩展范围与往年相比偏西1°左右,而在SE方向较往年有明显延伸扩展。水文结构特征为:(1)春季,温跃层主要在南黄海中部以西,跃层强度仅为0.10—0.40℃/m;密跃层主要在长江口以东,跃层强度0.20—0.30kg/m4;(2)夏季,温跃层强度最高值在长江口东北,跃层强度达到2.41℃/m,上界深度5.5m,厚度2.5m;黄海温跃层强度普遍强于东海,主要是冷水团区域表底显著的温度差异造成;密跃层强度高值区在33°N断面西侧海区,强度达到1.38kg/m4,上界深度5.5m,厚度约为1.5m;沿长江冲淡水舌轴方向的密跃层强度为0.30—0.60kg/m4,自西向东逐渐减弱。