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2003年冬季帕里西维拉海盆区上层水体中尺度涡的温盐特征 总被引：2，自引：2，他引：0
利用2003年冬季"科学一号"考察船在帕里西维拉海盆获得的CTD调查资料,结合同一时间西北太平洋海区的卫星高度计观测结果,分析讨论了该海区上层水体的温盐特征及其受中尺度涡活动的影响等。结果表明:在调查期间,研究区海域曾同时出现冷、暖涡活动过程,其影响深度均大于200m;冷涡活动区位于研究区内136°—138°E之间的海域,沿北东方向延伸;冷涡水体的盐度在100m以浅高于周围水体,在150m以深则低于周围水体;暖涡活动区出现在138.5°—139°E之间,暖涡活动特征在50m以浅水体中表现并不明显,其水体盐度在100m以深起初表现为低盐中心,在150m以深逐渐转化为高盐中心;研究区200m以浅水体可以大致分为三层,80m以浅为高温低盐的表层水,80—140m之间为受中尺度涡影响的温盐性质复杂的混合层水,140—200m之间为低温高盐的次表层水。 相似文献
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生源要素是海洋初级生产的基础，其在海洋环境中的循环受到多种物理、化学和生物过程的影响，对其浓度分布、结构特点及影响因素的认识是理解海洋生态系统动力学的基础。于2019年2月在南海北部神狐海域进行了现场考察和海水样品采集，对海水中的溶解态无机营养盐浓度进行了分析，并结合温度、盐度、叶绿素a(Chl a)、pH和溶解氧(DO)等水文环境参数，研究了神狐海域海水中营养盐浓度与结构的分布特征及影响因素等。在0～30 m的海水中各营养盐浓度均很低，随着深度的增加，营养盐浓度逐渐增大。在水深3 000 m左右处，无机氮、磷酸盐和硅酸盐浓度分别达到了38.02 μmol/L、2.71 μmol/L和149.07 μmol/L。温度、pH和DO与各营养盐浓度均具有显著的相关性，表明环境因素影响着营养盐的生物地球化学过程。此外，在75 m深度，研究区域东北方向的站位营养盐浓度相对较低，并呈现向西南方向逐渐增大的变化趋势，可能与高温、高盐和低营养盐的黑潮水入侵有关。根据端元混合模型计算所得保守混合浓度与实测值的差值显示，在75 m深度硅酸盐和磷酸盐以生物消耗为主，而硝酸盐存在添加。随磷酸盐浓度增加，各站位无机氮浓度呈线性升高，但硅酸盐浓度则以幂函数式升高，表明不同营养盐之间再生速率和再利用效率有所不同。神狐海域的N/P比与Si/N比和Si/P比呈现出截然相反的变化趋势。在0～30 m，N/P比较小而Si/N比和Si/P比较大；在75 m，受不同生物作用影响，N/P比变大，Si/N比和Si/P比变小；在75 m以下N/P比逐渐降低至14.44，而Si/N比和Si/P比则逐渐升高；在1 000 m以下，各营养盐比例均保持稳定。氮异常指数的计算结果显示，神狐海域300 m以上的海水中固氮作用强于反硝化作用，而300 m以下反硝化作用增强。神狐海域营养盐浓度与结构的分布特征表明黑潮入侵和生物活动显著影响了此区域营养盐的生物地球化学过程。 相似文献
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《热带海洋学报》2017,(4)
受夏季西南季风影响,南海西部会形成一支离岸急流,该急流通常与冷涡和暖涡组成偶极结构,共同影响该海域生态环境。本研究利用2014年9月现场和卫星数据,首次结合南海西部急流和冷暖涡过程,分析它们对该海域浮游植物粒径结构的影响。数据显示,表层以微微型浮游植物(0.2~2μm)为主,占总叶绿素a的平均比例为76.7%。在急流区中,微型浮游植物(2~20μm)和小型浮游植物浓度(20~200μm)占总叶绿素a平均比例相对较高,且与总叶绿素浓度呈线性正相关。暖涡区小型浮游植物比例(平均10.3%)高于冷涡区(平均3.6%)。结果表明,物理动力过程是南海西部夏季表层浮游植物粒径结构的主要影响因素。急流和冷暖涡可以提升小型浮游植物的比例,改变表层的粒径结构。急流对沿岸上升流区浮游植物的水平输送是表层小型浮游植物的主要来源。涡旋的辐合、辐散与急流的相互作用,导致各粒径浮游植物在冷涡边缘出现锋面分布,并且提高了暖涡区表层小型浮游植物的比例。冷涡的垂直抽吸作用加强了营养盐供给,也提高了冷涡中心表层小型浮游植物的比例。 相似文献
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2011-09应用高效液相色谱分离技术并结合CHEMTAX软件研究了中国南海西部冷涡和暖涡区浮游植物的群落结构组成.结果表明,南海西部优势类群为定鞭金藻、聚球藻和原绿球藻.中尺度涡影响了总叶绿素a(Chl a)的垂直分布和浮游植物群落组成,暖涡使叶绿素最大层下移,但冷涡并未使叶绿素最大层上移;同时,暖涡区定鞭金藻贡献量减少,原绿球藻和聚球藻贡献量增加,而冷涡区硅藻贡献量增加,聚球藻贡献量减少.中尺度涡并未显著影响南海西部浮游植物优势类群的优势地位,但其对水柱积分生物量的影响不同,暖涡区总叶绿素a显著增加,而冷涡区总叶绿素a无显著变化. 相似文献
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福建省同安湾叶绿素的含量 总被引：5，自引：0，他引：5
根据1998年2月、5月、8月、11月对同安湾叶绿素a含量的调查,分析了同安湾叶绿素a的季节分布,并估算了初级生产力C的含量,调查结果表明春季的叶绿素a含量为全年最高,范围为2.68 μg/L～16.24 μg/L,平均值为7.22 μg/L,初级生产力C平均为4286.4mg/m2.d;夏季叶绿素a含量为1.03μg/L～5.40 μg/L,平均值为.3.34 μg/L;秋季叶绿素a含量为0.36 μg/L～1.50 μg/L,平均值为0.87μg/L,初级生产力C平均为32.84mg/mg.d;冬季叶绿素a含量为1.11μg/L～2.21μg/L,平均值为1.56 μg/L.本文还将此次调查结果与历史资料作了比较. 相似文献
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文章依据2018 年8月、10月及2019年4月、6月庙岛群岛海域4个航次的调查资料,分析该海域不同月份DIN、PO4-P、SiO3-Si的平面分布及限制特征。结果表明：庙岛群岛海域DIN浓度范围为0.82~95.14 μmol/L,平均值为5.27 μmol/L,在2018年8月最高;PO4-P浓度范围为未检出至2.12 μmol/L,平均值为0.19 μmol/L,在2018年10月最高;SiO3-Si浓度范围为0.25~48.93 μmol/L,平均值为5.38 μmol/L,在2018年8月最高;总体而言,庙岛群岛海域夏季营养盐浓度较高,春季营养盐相对匮乏。庙岛群岛海域2018年8月、10月和2019年6月为PO4-P限制,2019年4月为SiO3-Si和PO4-P限制;PO4-P限制使海域初级生产力受到一定限制,对海水养殖业造成一定影响;SiO3-Si浓度低不利于硅藻生长,从而间接助长甲藻繁殖,因而庙岛群岛海域春季易引发赤潮。 相似文献
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热带太平洋西部及赤道暖水区的初级生产力 总被引：1，自引：2，他引：1
描述了对热带太平洋西部(1991年11月WOCE调查)及赤道暖水区(1992年11月至1993年2月的TOGA-COARE调查)的叶绿素a分布和初级生产力(C),及其与理化环境的关系.西部海域叶绿素a平均总量达19.79mg/m2,暖水区为2.168mg/m2;暖水区的潜在初级生产量高于西部海域,量值分别为228mg/(m2·d)和171mg/(m2·d),次表层最大值成为调查海域水体叶绿素a分布的一个明显特点.叶绿素a总量平面分布趋向表明:高生物量主要位于巴士海峡邻近、菲律宾以及伊里安岛的近岸站位,此外,在2°～4°N之间的观测区.低生物量主要位于外洋海域.生物量的分布与不同海域的物理过程变化有关,而海水涌升可能是导致温度、盐度和营养盐分布产生变化,并因而导致高生物量的一个重要的物理过程. 相似文献
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莱州湾及潍河口夏季浮游植物生物量和初级生产力的分布 总被引：9，自引：2，他引：9
于1998年6月黄河断流期在潍河口及其邻近海域进行了水文、化学和生物等专业综合外业调查.对此海区浮游植物叶绿素a浓度、脱镁色素浓度和初级生产力的变化进行了分析.研究结果表明,叶绿素a浓度介于0.089～5.444mg/m3之间,平均值为1.331mg/m3;脱镁色素浓度介于0.176～3.402mg/m3之间,平均值为0.905mg/m3.叶绿素a和脱镁色素浓度高密度区分布在小清河口附近、潍河口内及潍河口以外临近海域.初级生产力介于13.58～301.54mg/(d·m2)之间,平均值为62.49mg/(d·m2).水柱初级生产力高值区分布在小清河口和37.30°N,119.47°E附近.对水文、化学和浮游动物等环境因子与浮游植物生物量和初级生产力的相关性分析表明,整个调查区,浮游植物生物量和初级生产力与海区潮汐、光照、磷酸盐、硅酸盐和微型浮游动物等环境因子密切相关,同氨盐、硝酸盐和亚硝酸盐的作用不明显,其中潍河口内浮游植物的生物量分布同潮汐的关系最为密切.夏季此海域浮游植物生长主要受磷酸盐和硅酸盐的限制.调查海域浮游植物生物量及生产力水平较历史同期有所增加. 相似文献
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南黄海秋季叶绿素a的分布特征与浮游植物的固碳强度 总被引：24，自引：5，他引：19
依据2005年10月中下旬对南黄海的调查结果,系统阐述了2005年秋季南黄海叶绿素a的分布特征,并估算了南黄海和东中国近海初级生产力水平及浮游植物固碳强度,分析了控制其变化的生物地球化学机制.结果表明,南黄海表层叶绿素a含量的变化范围为0.11~2.38 mg/m3,平均浓度为0.66 mg/m3,明显高于50 m层的含量.南黄海表层和次表层叶绿素a分布趋势基本一致,均显现出西北高、东南低的趋势,在近岸海域出现显著的高值带,这主要是由于受到陆源输入和沿岸流带来的高营养盐的影响;中部海域的低值区则主要受控于来自东海低营养盐海流的“冲淡”作用.在垂直分布上,叶绿素a最高值基本出现在次表层,与以往发现的该海域次表层溶解氧最大值一致,这显然与南黄海浮游植物及区域水团特性有关.2005年秋季南黄海初级生产力(C)变化在95~1 634 mg/(m2·d),平均为586 mg/(m2·d),其分布趋势显示了海洋初级生产力与海水磷浓度以及水团、海流的关系.应用初级生产力估算的浮游植物固碳强度的结果表明,我国东部近海浮游植物年总固碳量约为222Mt,约占全球近海浮游植物的年固碳量的2.0%,为我国东部近海通过海-气界面总表观碳汇强度每年1 369万t的16.2倍,在不同的海域,浮游植物固碳量是其通过海-气界面总表观碳汇强度的倍数不同(渤海为3.0倍,黄海为6.7倍,东海为81.6倍). 相似文献
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From January 9 to 17, 1981, detailed observations of the horizontal and vertical structure beneath one of the quasi-permanent semi-stationary mesoscale offshore eddy signatures in the California Current System (CCS) discussed by Bernstein, Breaker and Whritner (1977), Burkov and Pavlova (1980), and Simpson (1982) were made. The vertical sections of temperature and density show the presence of three-layer system. A subsurface warm-core eddy, whose diameter is about 150 km at the 7°C isotherm, is the dominant feature. A warm surface layer, which extends to a depth of 75 m, lies over the eddy. Between the warm surface layer and the subsurface warm-core eddy, there is a cold-core region which extends to a depth of about 200 m. There is a high degree of symmetry about the vertical axis of rotation. Vertical sections of salinity and dissolved oxygen are entirely different from sections of temperature and density. Diagrams of water mass characteristics confirm that the core of the eddy, found between 250–600 m, consists of inshore water from the California Undercurrent (CU). Below about 700 m, local waters from the Deep Poleward Flow (DPF) have been incorporated into the eddy. The observed distributions of properties (T, S, δθ, O2) are inconsistent with a single, local generation process for the eddy system. Radial distributions of angular velocity, normalized gradient velocity and relative vorticity support the use of a Gaussian radial height field as an initial condition in eddy models. Possible reasons why CCS eddies may differ dynamically from Gulf Stream rings are given in the text. At the time the observations were made, the system as a whole was in near geostrophic balance. Local geostrophic balance, however, cannot explain the observed distribution of properties and structure. The observed symmetry in the structure of the eddy system, chemical evidence (Simpson, 1984), biological distributions (Haury, 1984) and satellite images of the CC (Koblinsky, Simpson and Dickey, 1984) suggest that lateral entrainment of warm (oceanic) and cold (coastal) water into the upper two layers of the three-layer system by the subsurface eddy is a likely generation mechanism for the cold-core region. The coastal origin of the frontal structure along the northeastern quadrant and the oceanic origin of the frontal structure along the southwestern quadrant of the eddy system further support lateral entrainment as a generation mechanism for the cold core. This entrainment makes the CCS eddy system different from cold-core rings in the Gulf Stream and rather similar to some warm-core eddies found in the East Australian Current. The presence of CU water in the core of this eddy raises the question of how CU water was transported from the continental slope. Eddy generation mechanisms, other than baroclinic instability of the CC, may be required to explain the distribution, persistence, and core composition of offshore mesoscale eddies in the CCS. There is evidence that barotropic, in addition to baroclinic, processes may be important. 相似文献
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J.J. Simpson 《Progress in Oceanography》1984,13(1):71-93
From January 9 to 17, 1981, detailed physical, chemical and biological measurements were made through the historical surface signature (Berstein, Breaker and Whritner, 1977; Burkov and Pavlova, 1980; Simpson, 1982) of a warm-core eddy in the California Current System. The data show a three-layer system: surface layer to 75 m, intermediate cold-core region to about 200 m, and the physically dominant subsurface warm-core eddy to about 1400 m. The chemical structure simultaneously possesses characteristics of both warm- and cold-core eddies. This structure results from a complex interplay among non-local eddy generation processes at the time the three-layer system was formed and a continuous set of interactions within the three-layer system, both inshore (cold) and offshore (warm) waters of the California Current and coastal and local biological processes (e.g. this California Current System eddy is an isolated structure like some Gulf Stream rings). The dominant biological/chemical process in the euphotic zone is phytoplankton photosynthesis; photosynthetic alteration of the chemical structure below 100 m is much reduced. The effects of heterotrophic activity on the deeper-lying chemical structure, however are not as significant as those of autotrophs on the chemical structure of the euphotic zone. Hence, below 100 m, the distribution and structure of chemical properties is controlled primarily by physical processes. The continuous set of interactions of the three-layer system with coastal and oceanic waters of the California Current make this offshore eddy in the California Current System fundamentally different chemically and biologically from cold-core Gulf Stream rings and rather similar to some of the warm-core eddies found in the East Australian Current. 相似文献
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L.R. Haury 《Progress in Oceanography》1984,13(1):95-111
The distribution of plankton across a warm-core eddy system in the California Current 400 km off Point Conception, California was studied in January 1981. The eddy system, about 150 km in diameter at the 7°C isotherm, was made up of a 75 m thick surface layer, a cold-core region extending from 75 m to about 200 m, and a warm-core eddy below 200 m extending to at least 1450 m. Casts for the vertical distribution of chlorophyll/phaeophytin and integrating zooplankton net tows were taken at 37 stations located about 20 km apart on two orthogonal transects across the eddy system. Vertical distributions of microplankton were determined on one section from the eddy center to beyond the eastern edge. Integrated chlorophyll/phaeophytin values were highest to the north and east of the eddy system; across the system itself, there was only a small increase of values near the center. Asymmetrical distributions of maximum concen Current water was being entrained into the center of the eddy system from the northeast. Dinoflagellates were numerically the most important member of the microplankton, especially in the deep chlorophyll maximum. Zooplankton distributions indicated the intermingling of warm and cool water species throughout at least the upper 200 m of the eddy system. Some cold water species were as abundant inside the system as outside to the north and east; their numbers were much reduced in a band surrounding the system where warm water species were most abundant. The presence of species characteristic of different water types throughout the region of the eddy system provides an indication of the mixing that had occurred since the system originally formed. The biological data, together with the physical and chemical results, indicate the importance of frontal boundary processes and lateral entrainment of surrounding water into the eddy system in determining the character and productivity of such systems. 相似文献
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根据１９８８年夏季台湾海峡海域的调查资料讨论福建北部沿岸和台湾北面海域水化学的区域性特征。结果表明，福建沿岸上升流是西部海域诸化学要素分布的控制因素。台湾北面海域（２５°５０′－２６°４０′Ｎ，１２１°４５′－１２２°３０′Ｅ）水体下层出现局部冷水抬升，福建沿岸和台湾北面海域都具有低溶解氧且不饱和、高营养盐、低温、高盐的特征，溶解氧、诸营养盐与温度、盐度分别有良好的相关关系。 相似文献
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针对海洋中尺度涡对水声传播的影响,利用中尺度涡区的历史水文实测数据提取涡旋强度,空间尺度等中尺度涡特征参数,建立了海洋中尺度涡理论计算模型。运用MMPE水下声场模型仿真试验研究了涡旋性质、强度和位置、声源频率和置放深度对声传播特性的影响。结果表明：暖涡使得会聚区的位置“后退”,会聚区宽度增加;冷涡使得会聚区的位置“前移”,会聚区宽度减小。涡旋的强度越大,“前移”或“回退”的效应越显著。 相似文献
16.
根据2018年南黄海漂浮态浒苔(Ulva prolifera)绿潮规模卫星监测数据以及春、夏季(4月和7月，绿潮前后)水文环境要素和氮营养盐等数据，对2018年绿潮发展规律及不同氮组分在其中的作用进行分析。结果表明:浒苔于4月25日在江苏南通近海首次发现，随后其向北漂移增殖扩展在6月29日达到最大规模，8月中旬消失。绿潮漂移区域集中在122°E以西近海并呈现两个明显的发展阶段:35°N以南江苏近海绿潮快速增殖阶段和35°N以北山东半岛外海域绿潮聚积衰退阶段。各氮营养盐组分受径流输入、冷水团以及生物活动等因素影响，呈现明显的区域和季节特征。不同绿潮阶段受氮营养盐影响不同，绿潮快速增殖阶段，丰富的氮营养盐(总溶解氮(TDN)>20 μmol/L和溶解无机氮(DIN)>20 μmol/L)是浒苔藻快速繁殖生长的物质基础，此阶段为整个绿潮发展提供了主要的氮支撑且以DIN为主要形态。绿潮聚积衰退阶段，较低的可利用氮(DIN<2 μmol/L和尿素(urea-N)<1.5 μmol/L)不利于浒苔藻持续繁殖生长，此阶段内有机氮(如urea-N)在绿潮后期的氮支撑中起到重要作用。 相似文献
17.
Ship and satellite observations taken over the last thirty years show that mesoscale patterns of sea surface temperature (SST) in the California Current System are consistently found throughout the year and usually occur in approximately the same geographical locations. Typically, these patterns are more pronounced in fall/winter than in spring/summer. The temporal and spatial characteristics of these persistent feature were examined with satellite infrared (IR) measurements during winter 1980–1981. In January 1981, a ship surveyed the vertical structure of several physical, chemical, and biological parameters beneath one of these SST features centered near 32°N, 124°W. The surface IR pattern had a length scale of 200 km and a time scale of about 100 days. It disintegrated following the first two storms of the winter season. Motion studies of the pattern in late October indicated an anticyclonic rotation with maximum velocities of 50 cm s?1 at 50 km from the axis of rotation. As a unit, the pattern advected southward with an average speed of 1 cm s?1. Thermal fronts, determined from the satellite imagery, were strongest (0.4°C km?1) along the rim of the pattern and were advected anticyclonically with the pattern; their length scales were 20–30 km in the along-front direction and less than 10 km wide. The hydrographic data revealed a three-layer structure beneath the surface pattern; a 75 m deep surface layer, a cold-core region from 75 to 200 m depth, and a warm-core eddy extending from 250 to 1450 m. The anticyclonic motion of the surface layer was caused by a geostrophic adjustment to the surface dynamic height anomaly produced by the subsurface warm-core eddy. The IR pattern observed from space reflects the horizontal structure of the surface layer and is consistent with a theoretical model of a mean horizontal SST gradient perturbed by a subsurface density anomaly. Ship of opportunity SST observations collected by the National Marine Fisheries are shown to resolve mesoscale patterns. For December 1980, the SST pattern near 32°N, 124°W represented a 2°C warm anomaly compared with the 20-year mean monthly SST pattern. 相似文献
18.
Interaction of an anticyclonic eddy with sea ice in the western Arctic Ocean: an eddy-resolving model study 总被引：1，自引：0，他引：1
The dramatic decline of summer sea ice extent and thickness has been witnessed in the western Arctic Ocean in recent decades, which hasmotivated scientists to search for possible factors driving the sea ice variability. An eddy-resolving, ice-ocean coupled model covering the entire Arctic Ocean is implemented, with focus on the western Arctic Ocean. Special attention is paid to the summer Alaskan coastal current (ACC), which has a high temperature (up to 5℃ ormore) in the upper layer due to the solar radiation over the open water at the lower latitude. Downstream of the ACC after Barrow Point, a surface-intensified anticyclonic eddy is frequently generated and propagate towards the Canada Basin during the summer season when sea ice has retreated away from the coast. Such an eddy has a warm core, and its source is high-temperature ACC water. A typical warm-core eddy is traced. It is trapped just below summer sea ice melt water and has a thickness about 60 m. Temperature in the eddy core reaches 2-3℃, and most water inside the eddy has a temperature over 1℃. With a definition of the eddy boundary, an eddy heat is calculated, which can melt 1 600 km2 of 1mthick sea ice under extreme conditions. 相似文献
19.
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