A comparative analysis of compositional variations in and between marine ferromanganese nodules and crusts in the South Pacific and their environmental controls     

Philomène A. Verlaan Author Vitae  David S. Cronan Author Vitae  Charles L. Morgan Author Vitae 《Progress in Oceanography》2004,63(3):125-158

Regional variation of Mn, Fe, Co, Ni and Cu in ferromanganese oxides (nodules and crusts) in the central south Pacific is related to primary productivity, oxygen minimum layer, and calcium carbonate compensation depth. The largely latitudinal influence of these environmental parameters on nodule and crust composition reflects their predominantly latitudinal variation. Primary productivity is the principal regional environmental control, influencing diagenetic enrichment of these elements in nodules through its effect, mediated by the CCD, on supply and concentration of labile organic matter vs. carbonate remains to the sediments. It influences hydrogenetic enrichment of these elements in nodules and crusts through its effect, mediated by the oxygen minimum layer (mainly in the case of crusts), on their export from surface waters.The elements’ varying susceptibility to being scavenged or organically bound influences the contrasting composition of diagenetic vs. hydrogenetic ferromanganese oxides, which is further influenced by depth. Hydrogenesis is the fundamental process governing nodule and crust formation, superimposed on which is diagenesis under specific circumstances; both are subject to intermittent interruption, diminution and augmentation by changes in environmental parameters. Application of regionally operative environmental controls locally explains local compositional variations and helps refine exploration criteria for economically viable nodules and crusts.  相似文献   

Finite element modeling of net panels using a consistent net element   总被引：3，自引：0，他引：3  

Igor Tsukrov  Oleg Eroshkin  David Fredriksson  M. Robinson Swift  Barbaros Celikkol 《Ocean Engineering》2003,30(2):251-270

A consistent finite element is proposed to model the hydrodynamic response of net panels to environmental loading. This equivalent net element is constructed to reproduce the drag, buoyancy, inertial and elastic forces exerted on the netting by current and waves. To evaluate the accuracy of the proposed finite element modeling, numerical predictions have been compared with the experimental observations and (simplified) analytical results of other authors. This new modeling technique has been applied to evaluate the performance of a tension leg fish cage in the open ocean environment.  相似文献   

长江口北支进入南支净盐通量的观测与计   总被引：3，自引：0，他引：3  

茅志昌  沈焕庭  陈景山 《海洋与湖沼》2004,35(1):30-34

根据 2 0 0 1年 4月 1 0— 1 3日长江口大潮期 5个潮周期 3条测量船的同步连续观测资料 ,计算了长江口北支进入南支的净盐通量为 5 4 5× 1 0 6 t,这一结果为预测长江口南支及青草沙水源地的咸潮入侵强度和开发利用长江口淡水资源提供了重要数据。  相似文献   

胶州湾口内初级生产力的周年定点观测   总被引：10，自引：1，他引：10  

潘友联  郭玉洁  曾呈奎 《海洋与湖沼》1995,26(3):309-316

于１９８３年１１月－１９８５年１１月利用黑白瓶测氧法研究了胶州湾东南部的初级生产力及其与各环境因子的关系。结果表明，调查区内初级生产力的变化范围是０．１０－２．８２ｇ／（ｍ＾２．ｄ）碳，年初级生产量的平均是２０６ｇ／ｍ＾２碳，夏半年（５－１０月）的初级生产量平均占全年生产量的７３．４５％，浮游植物的光合作用对有效太阳辐射能的平均利用率是０．６４％，初级生产力与水温，日太阳辐射能等均呈明显的正相磁，  相似文献   

Bio-optical signatures and biogeochemistry from intense upwelling and relaxation in coastal California     

Raphael M. Kudela  Newell Garfield  Kenneth W. Bruland 《Deep Sea Research Part II: Topical Studies in Oceanography》2006,53(25-26):2999

The NSF-sponsored Coastal Ocean Processes Wind Events and Shelf Transport (WEST) experiment investigates the interplay between wind-driven transport and shelf productivity; while eastern boundary shelves are characterized by high productivity due to upward fluxes of nutrients into the euphotic zone, wind forcing also represents negative physical and biological controls via offshore transport and deep (light-limiting) mixing of primary producers. Although this interaction has been well documented for eastern boundary systems generally and for California specifically, one of the primary goals of WEST was to characterize more fully the interplay between positive and negative effects of wind stress, which result in the consistently elevated biological productivity in these shelf regions. During 3 month-long summer cruises (2000–2002) we observed extremes in upwelling/relaxation, using both in situ instrumentation and remotely sensed data. Relationships between optical and physical properties were examined, with emphasis on biogeochemical implications. During 2000, the WEST region was optically dominated by phytoplankton and covarying constituents. During 2001 and 2002, periods of more intense upwelling favorable winds, we observed a transition to optical properties dominated by detrital and inorganic materials. In all years, the continental shelf break provided a natural boundary between optically distinct shelf and open ocean waters. During 2002, we obtained discrete trace-metal measurements of particulate iron and aluminum; we develop a bio-optical proxy for acetic-acid leachable iron from backscatter and fluorescence, and demonstrate that particulate iron is not well correlated to traditional upwelling proxies such as macronutrients, temperature, and salinity. We conclude that the shelf break between ca. 100 and 200 m water depth serves as a natural break point between coastal and oceanic water masses in this region, and that the elevated biomass and productivity associated with this eastern boundary current regime is dominated by these iron rich, shallow shelf waters.  相似文献   

关于登州浅滩作用的研究   总被引：3，自引：0，他引：3  

武桂秋  孟祥东  夏东兴  崔金瑞 《海洋与湖沼》1997,28(4):419-425

１９９０－１９９３年对蓬莱西庄海岸附近海域进行了水文、水深、地质地貌和泥沙等１３项测量和调查。整理分析实测资料并结合数值计算，首次分析研究了登州浅滩的作用并着论述了浅滩被破坏后袭击岸边的波浪增大，波能增中到５－７倍，沿岸输沙量增中到３－５倍。文中指出西庄海岸侵蚀加剧的主要原因是，登州浅滩被破坏后失去防浪消波作用而造成的。  相似文献   

铁在海洋初级生产过程中的作用   总被引：2，自引：0，他引：2  

朱明远  牟学延  李瑞香 《海洋科学进展》1997,(3)

海洋浮游植物的光合作用固定了占全球将近40×10-2的碳，但对于制约浮游植物生物量和初级生产力的诸多因子却研究较少。近来许多研究表明，不论是在氛盐的高值还是低值水域，铁元素的供应对浮游植物的生物量、生长率、种类组成及初级生产力均会产生影响。一些生理的和分子生物学的指标可用来指示铁对浮游植物的限制．这些指标包括：叶绿素a、光系统Ⅱ光化学反应的量子产率、以及某些特定酶的活性如过氧化氢酶、脂氧合酶、黄素氧还蛋白等。  相似文献   

河北邯郸056038,河北邯郸056038,河北邯郸056038绿化现     

状  绿化树种 《气象学报》2007,(3)

钅?20051010-4)0安徽农业科学Journal of Anhui Agricultural Sciences93+148TU985C038;D049;3;34;C;D;D049_34;C038_3;杨凤云;2911+2966不同来源大白猪生长曲线的比较研究肖炜;云鹏;李光兵;黄国英;路永强;王楚端;北京市畜牧兽医总站,北京市畜牧兽医总站,北京华都种猪繁育公司,北京华都种猪繁育公司,北京市畜牧兽医总站,中国农业大学动物科技学院 北京100107,北京100107,北京101407,北京101407,北京100107,北京100094猪;;生长规律;;生长曲线;;背膘厚对70~190日龄的32头英国大白猪1、7头法国大白猪和11头美国大白猪,每隔15 d测定体重和背膘厚,分析其生长发育规律。结果表明:Logistic、Bertanlanffy和Gompertz模型均可较好拟合3个品系大白猪在生长肥育期的生长曲线(p<0.000 1),但Logistic模型更加适合这3个品系大白猪;英国、法国和美国大白猪生长肥育猪分别在125日龄(体重为71.40 kg)1、43日龄(体重为84.25 kg)1、37日龄(体重为86.85 kg)时,日增重最大,分别为0.860 4、0.897 3和1.063 9 kg/d。英国大白猪、法国大白猪体重达120 kg左右时的背膘厚分别为11.751、6.87 mm,小于William认为的具有良好繁殖性能的22 mm。北京市科技计划  相似文献   

The Energy Balance Experiment EBEX-2000. Part III: Behaviour and quality of the radiation measurements     

W. Kohsiek  C. Liebethal  T. Foken  R. Vogt  S. P. Oncley  Ch. Bernhofer  H. A. R. Debruin 《Boundary-Layer Meteorology》2007,123(1):55-75

An important part of the Energy Balance Experiment (EBEX-2000) was the measurement of the net radiation and its components. Since the terrain, an irrigated cotton field, could not be considered homogeneous, radiation measurements were made at nine sites using a variety of radiation instruments, including pyranometers, pyrgeometers and net radiometers. At several of these sites multiple instruments were employed, which enabled us to compare instruments and assess accuracies. At all sites the outgoing longwave and shortwave radiation and the net radiation were measured, while the incoming radiation was supposed to be uniformly distributed over the field and was therefore measured at three sites only. Net radiation was calculated for all sites from the sum of its four components, and compared with the direct measurement of net radiometers. The main conclusions were: (a) the outgoing shortwave radiation showed differences of up to 30 W m⁻² over the field; the differences were not clearly related to the irrigation events; (b) the outgoing longwave radiation showed differences of up to 50 W m⁻²; the differences increased during the periods of irrigation; (c) the net radiation showed differences of several tens of W m⁻² across the field, rising to 50 W m⁻² or more during the periods of irrigation; (d) the net radiation is preferably to be inferred from its four components, rather than measured directly, and (e) attention should be paid to the characteristics of pyranometers that measure the outgoing radiation, and thus are mounted upside down, while they are commonly calibrated in the upward position. The error in the net radiation at EBEX-2000 is estimated at max (25 W m⁻², 5%) per site during the day and 10 W m⁻² at night. The National Center for Atmospheric Research is supported by the National Science Foundation.  相似文献   

Inhibition of primary production by UV-B radiation in an arctic bay – model calculations     

Sten-Åke Wängberg  Kristin I. M. Andreasson  Kristine Garde  Kim Gustavson  Peter Henriksen  Thomas Reinthaler 《Aquatic Sciences - Research Across Boundaries》2006,68(2):117-128

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