Growth of chum salmon (Oncorhynchus keta) correlated with sea-surface salinity in the North Pacific   总被引：1，自引：0，他引：1  

Morita  Shoko H.; Morita  Kentaro; Sakano  Hiroyuki 《ICES Journal of Marine Science》2001,58(6):1335-1339

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Optical water type discrimination and tuning remote sensing band-ratio algorithms: Application to retrieval of chlorophyll and K_d(490) in the Irish and Celtic Seas     

David McKee  Alex Cunningham  Agnes Dudek 《Estuarine, Coastal and Shelf Science》2007,73(3-4):827-834

This paper assesses the feasibility of applying remote sensing algorithms based on blue/green reflectance ratios to Case 2 waters. Two algorithms from the SeaDAS (NASA) image processing package, OC4v4 for surface chlorophyll concentration, Chl, and K(490) for the attenuation coefficient for downward irradiance at 490 nm, K_d(490), were investigated using an extensive set of observations from the Irish and Celtic Seas. In situ data from a profiling radiometer were used as inputs for the algorithms to avoid uncertainties in atmospheric correction procedures, and direct measurements of Chl and K_d490 and were used for validation purposes. The standard versions of the algorithms performed poorly: OC4v4 generally overestimated Chl (with a very low coefficient of determination), and K(490) progressively underestimated K_d490 for values greater than 0.3 m⁻¹. A two-step procedure for level 2 product generation was therefore devised in which the numerical coefficients of OC4v4 and K(490) were tuned for the two optical water types known to occur most frequently in this region (McKee, D., Cunningham, A., 2006. Identification and characterisation of two optical water types in the Irish Sea from in situ inherent optical properties and seawater constituents. Estuarine, Coastal and Shelf Science 68, 305–316) by statistical regression on a data set of 102 stations from the Irish and Celtic Seas. The water types were distinguished by the magnitude of their normalised water leaving radiance signals at 665 nm, nL_w(665), and appropriate versions of the tuned algorithms applied to each water type. When this procedure was tested on an independent data set of 19 stations from the Bristol Channel, Chl values were recovered with an RMS error of 0.36 mg m⁻³ and K_d(490) values with an RMS error of 0.095 m⁻¹. The identification of water types from water-leaving radiance signals, and the application of band-ratio algorithms tuned for specific water types, may therefore provide a simple means of improving the quality of remote sensing products in optically complex shelf seas.  相似文献   

Experimental Study on Vortex-Induced Vibrations of Submarine Pipeline near Seabed Boundary in Ocean Currents   总被引：2，自引：3，他引：2  

杨兵高福平  吴应湘李东晖 《中国海洋工程》2006,20(1):113-121

1 .IntroductionThe submarine pipeline is a commonfacility widely usedfor offshore oil and gastransport . Whena pipeline is installed on a seabed and not buried,unsupportedspans may exist insomelocations ,es-peciallyinthe uneven zones of the seabed.The spa…  相似文献   

南海海域叶绿素浓度分布特征的卫星遥感分析   总被引：17，自引：5，他引：17  

陈楚群  施平  毛庆文 《热带海洋学报》2001,20(2):66-70,T001

介绍了第二代海洋水色传感器SeaWiFS资料的特点汲其基本处理方法，海水叶绿素浓度提取方法，对南海域表层海水叶绿素浓度分布的时空变化特征及其与营养物质和南海环流的关系进行了初步分析。  相似文献   

海洋环境荷载下输液立管的静、动力特性研究   总被引：1，自引：1，他引：1  

郭海燕  王树青  刘德辅 《中国海洋大学学报(自然科学版)》2001,31(4):605-611

考虑管内流动流体和管外海洋环境荷载共同作用 ,建立海洋立管侧向运动微分方程。用Hermite插值函数离散 ,在微机上编写海洋立管静、动力分析程序 ,通过计算分析研究管内流体对立管侧向变形和应力的作用 ;另外 ,探讨管内流体的流动速度和立管顶端的预张力对立管动力特性的影响。结果表明 ,立管变形和应力均随管内流体流动速度增加而增大 ,同时内流速度的增大会降低立管的固有频率 ,但适当增大立管顶端预张力会抵消内流流速增加引起的固有频率下降。  相似文献   

三次样条函数在海洋水文资料整理中的应用     

郑东 《中国海洋大学学报(自然科学版)》1989,(Z1)

本文引入三次样条函数插值法,并尝试用于海洋资料处理。根据渤海及北黄海部分海洋站的历史资料进行了试验。用SHARP—PC—1211袖珍计算机进行计算,并将资料处理的结果与传统的过程曲线法订正值作了比较。结果表明,二者之间的误差不大,而样条函数拟合更好。作者认为三次样条函数插值法是可行的,在处理海洋资料时间序列中是有效的。在有温跃层的地方,如何应用,本文也给出了必要的说明。  相似文献   

Influence of stratification and irradiance regime on summer phytoplankton composition in coastal and shelf seas of the British Isles   总被引：1，自引：0，他引：1  

K. J. Jones  R. J. Gowen 《Estuarine, Coastal and Shelf Science》1990,30(6)

The effect of interaction between stratification and irradiance regimes on phytoplankton community structure was investigated in three shelf/coastal regions of the British Isles, each of which displayed ranges of vertical stability and light attenuation. Relationships between vertical stability, light penetration and community structure were indicated by the ordination of dominance (assessed using cell volume) of the main phytoplankton phyletic groups—diatoms, dinoflagellates and microflagellates—on a surface defined by a bulk stratification index () and water column depth, scaled by transparency (λh). Diatom- and dinoflagellate-dominated communities occupied distinctly different domains on the - λh surface, diatoms being favoured in well-mixed water columns with high values for λh and dinoflagellates dominating where stratification was strong and λh was low. Microflagellates were not abundant in any of the study areas and showed no clear ordination on the - λh surface. The domain of co-dominance of diatom and dinoflagellates on the - λh surface was narrow with small changes in the irradiance or stratification regime resulting in a switch to diatom or dinoflagellate dominance. It is suggested that loss of non-motile diatom communities in strongly stratified water columns might be a strong selective force in favour of dinoflagel-lates. However, in water columns with intermediate stratification and optical properties, the outcome of competition may be decided by physiological attributes of the two groups with respect to growth in low and fluctuating irradiances.  相似文献   

The combined effect of transport and temperature on distribution and growth of larvae and pelagic juveniles of Arcto-Norwegian cod   总被引：5，自引：0，他引：5  

Vikebo  Frode; Sundby  Svein; Adlandsvik  Bjorn; Fiksen  Oyvind 《ICES Journal of Marine Science》2005,62(7):1375-1386

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Reynolds stress and TKE production in an estuary with a tidal bore   总被引：4，自引：0，他引：4  

J. H. Simpson  N. R. Fisher  P. Wiles 《Estuarine, Coastal and Shelf Science》2004,60(4):619-627

We report new measurements of the turbulent properties of the flow in a tidally energetic estuarine channel of almost uniform cross-section. A high-frequency (1.2 MHz), bottom-mounted Acoustic Doppler Current Profiler (ADCP) has been used to observe the velocity field at a sampling rate of 10 Hz in parallel with measurements of the surface elevation by tide gauges. Our data have been analysed using the Variance Method to determine turbulent kinetic energy (TKE), shear stress and TKE production over the tidal cycle with a time resolution of 60 s. During the highly energetic but brief flood period, when the surface axial velocity reaches 2 m s⁻¹, we observed large values of stress (>2 Pa) and shear production (5 W m⁻³). TKE is also input through the release of energy in the bore itself which results in a brief but intense injection of energy at the bore front with large transient TKE levels (100 J m⁻³). Subsequent input by shear production maintains TKE levels which are generally lower (20 J m⁻³) than the strong peak associated with the bore for the rest of the flood. On the ebb, the flow is relatively tranquil with maximum speeds 0.5 m s⁻¹ and peak TKE production rates of 0.1 W m⁻³.The flow and elevation data have also been used to estimate the energy fluxes into and out of the estuary. Short (1 h), intense energy inputs (8 MW at springs) on the flood flow are largely balanced by longer, less intense seaward energy flow on the ebb. The net energy input is found to be 0.1 MW at springs which is consistent with estimates of upstream dissipation. Peak dissipation in the bore itself may exceed the mean energy input but it is active only for a small fraction of the tidal cycle and its average contribution does not exceed 12% of total dissipation.  相似文献   

太平洋年代际海洋变率研究进展   总被引：10，自引：1，他引：10  

王东晓  谢强  刘赟  刘钦燕  杜岩 《热带海洋学报》2003,22(1):76-83

随着“气候变率与可预报性研究”（CLIVAR计划）的实施，年代际气候变率研究已经成为国际气候研究的一个新热点，由于海洋特别是海洋次表层具有巨大的热损性，海洋环流在年代际气候变率中所起的作用已得到越来越多的重视。但迄今为止，海洋以什么方式参与到年代际气候变化中，海洋次表层在年际和年代际时间尺度上起到什么作用这些与海洋环流有关的问题仍未得到解决，而这些问题的解决将有助于建立一种完备的年代际气候变化机制的理论，文章通过对近10a来国内外在该领域内研究进展的回顾，提出了一个关于太平洋年际变化（如ENSO循环）和年代际变化（如PDO循环）相互作用的猜想，为今后在国内开展相关研究提供了一些设想。  相似文献