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1.
Choi Young-Kwang Seo Seung-Nam Choi Jin-Yong Shi Fengyan Park Kwang-Soon 《海洋学报(英文版)》2019,38(7):36-47
A wave forecasting system using FUNWAVE-TVD which is based on the fully nonlinear Boussinesq equations by Chen(2006) was developed to provide an accurate wave prediction in the Port of Busan, South Korea. This system is linked to the Korea Operational Oceanographic System(KOOS) developed by Park et al.(2015). The computational domain covers a region of 9.6 km×7.0 km with a grid size of 2 m in both directions, which is sufficient to resolve short waves and dominant sea states. The total number of grid points exceeds 16 millions,making the model computational expensive. To provide real-time forecasting, an interpolation method, which is based on pre-calculated results of FUNWAVE-TVD and SWAN forecasting results at the FUNWAVE-TVD offshore boundary, was used. A total of 45 cases were pre-calculated, which took 71 days on 924 computational cores of a Linux cluster system. Wind wave generation and propagation from the deep water were computed using the SWAN in KOOS. SWAN results provided a boundary condition for the FUNWAVE-TVD forecasting system. To verify the model, wave observations were conducted at three locations inside the port in a time period of more than 7 months. A model/model comparison between FUNWAVE-TVD and SWAN was also carried out. It is found that, FUNWAVE-TVD improves the forecasting results significantly compared to SWAN which underestimates wave heights in sheltered areas due to incorrect physical mechanism of wave diffraction, as well as large wave heights caused by wave reflections inside the port. 相似文献
2.
Lakshmi H. Kantha 《Marine Geodesy》2013,36(4):275-297
Progress in tidal science has been rapid in recent years. The advent of precision altimetry has enabled, for the very first time in tidal history, an accurate measurement of tides in most of the global oceans. This has revolutionized our knowledge of tides and tidal processes. Combined with high‐resolution numerical models of tides (and other recent advances in astronomy and geodesy), this increased knowledge is providing valuable assistance in effecting closure on many outstanding problems in this three‐centuries‐old science. For example, we now know the dissipation rate of lunar tides to be 3.17 TW to within 2%. However, there do remain some outstanding issues. While we know the rate at which tidal energy is being dissipated in the global oceans, there is still considerable uncertainty as to the mechanisms, locations, and magnitudes of various tidal energy sinks. Imminent advances in shallow‐water barotropic and deep‐water baroclinic tides hold the prospect of a better understanding of these also. Improved knowledge of oceanic tides and high‐precision satellite measurements of tides are enabling better assessment of some matters of geophysical interest, such as the anelasticity and the length‐of‐day fluctuations of the Earth's mantle. It has been possible to map long‐period lunar tides more accurately and derive their contribution to the Earth's rotation rate fluctuations and its anelasticity at these frequencies. We discuss various aspects related to tides, including tidal dissipation and its consequences, as well as several other topics such as tidal energetics, internal tides, and long‐period tides, where considerable progress has been made in the last decade. Both oceanographic and geophysical implications are mentioned. 相似文献
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《海洋气象学报》2016,(4)
根据海阳1961—2010年气温、降水量、日照、相对湿度等气象资料,应用气候倾向率、Mann-Kendall突变检测法、滑动t检验法,对海阳市气候变化及规律进行了分析。结果表明:历年平均气温、平均最高气温、平均最低气温、极端最低气温在过去的50a间呈显著的上升趋势,历年极端最高气温的上升趋势不显著,年代际变化特征突出;年降水量呈缓慢的减少趋势,变化趋势不显著,年代际间分布不均,变化较大,年降水量减少的原因是夏季和秋季降水减少;日照时数呈显著减少趋势,发生突变的时间点是2004年;年平均相对湿度呈现显著减少趋势,发生突变的时间点是1977年,秋季湿度减少最为明显。 相似文献
4.
Li Yucheng Zhang Ningchuan
Professor Dalian University of Technology Dalian . Lecturere Delian University of Technology Dalian 《中国海洋工程》1994,(1)
- A composite pipeline is defined as a main big pipe composed of one or several small pipes. The flow behaviour around a submarine composite pipeline is more complicated than that around a single submarine pipeline. A series model test of composite pipelines in a wave-current coexisting field was conducted by the authors. Both in-line and lift forces were measured, and the resultant forces were also analyzed. The results of lift forces and resultant forces are reported in this paper. It is found that the lift force coefficients for composite pipelines are well related to the KC number. The lift force coefficients for an irregular wave-current coexisting field are smaller than those for a regular wave-current coexisting field. The frequency of lift force is usually twice the wave frequency or higher. The authors test indicates that the resultant forces are about 10 to 20 percent larger than in-line forces (horizontal forces). The effect of water depth is analyzed. Finally, the relationship between lift f 相似文献
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首次提出并探索了采用单一参数叶绿素a进行赤潮短期预报的原理和技术。该原理主要以叶绿素a大于某一基准值时连续2d是否呈指数增长来判定未来1～3d内是否会发生赤潮。对于任何海区，都仅基于叶绿素a基准值和增长速率下限两个常数即可进行预报操作。 相似文献
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Lian Gan Ni Kan Hu Kai Guo Dawei Prof. Senior Engineer Marine Design Research Institute of China Shanghai Senior Engineer Marine Design Research Institute of China Shanghai Engineer Marine Design Research Institute of China Shanghai 《中国海洋工程》1991,(4)
In this paper, a single-column structure used as well-head platform is studied. The loads of wave and current exerted on the single-column will be greatly reduced, therefore the cost of the structure will be decreased. The advantages of the single-column structure compared with ordinary jacket structure are explained. A dynamic analysis of this type of structure is made and some problems related to dynamic analysis are solved. In order to check the reliability of computation theory and programme, model tests have been carried out. However, as space is limited, the conclusion of tests will be introduced in another paper. Therefore, this type of structure is applicable for proctical engineering. 相似文献
9.
从2009年5月到2010年3月,选择代表月份对白洋淀水体中叶绿素a浓度的时空分布进行了调查并分析了白洋淀的水质特征。结果表明,白洋淀叶绿素a有明显的时空分布规律:夏季(平均含量为41.19mg/m3)>秋季(平均含量为40.42mg/m3)>春季(平均含量为16.95mg/m3)>冬季(平均含量为10.30mg/m3);空间方面,清洁对照点最低(年平均值为10.65mg/m3),养鱼点含量最高(年平均值为42.11mg/m3)。叶绿素a的含量变化范围是4.37～97.45mg/m3,表明白洋淀处于富营养化水平。叶绿素a的含量与其他水质因子呈现一定的相关性:与水温、透明度、总铁、总磷之间有较高的相关性,与CODMn之间相关程度显著,与总氮相关程度较小。 相似文献
10.
《Marine Policy》2017
The phenomenon of maritime clusters has spawned a rich body of scholarly work in the last fifteen years. Yet, the answer to one important question has remained elusive: what is a maritime cluster? This question is important because maritime clusters have rapidly become the focus of economic competitiveness policies promoted by both firms and policymakers. This study reviews research articles published over a 15-year period that investigate maritime clusters and derives three distinct definitions of a maritime cluster from them: an industrial complex, an agglomeration of interlinked industries, and a community-based network. 相似文献
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This paper examines the simplification strategy of retaining only the nonhydrostatic effect of local acceleration in a three-dimensional fully nonhydrostatic model regarding the submesoscale wave phenomenon in the ocean.Elaborate scale analysis of the vertical component of the Reynold-averaged Navier–Stokes(RANS) equation was performed, confirming the rationalization of this simplification. Then, the simplification was implemented in a RANS equation-based nonhydrostatic model NHWAVE(nonhydrostat... 相似文献
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LIU Yong LI Yucheng TENG Bin MA Baolian 《海洋学报(英文版)》2007,26(3):129-141
The reflection of regular and irregular waves from a partially perforated caisson breakwater with a rock-filled core is examined. The present mathematical model is developed by means of the matched eigenfunction method. Numerical results of the present model are compared with the experimental data of different researchers. Numerical examples are given to examine the effect of rock fill on the reflection coefficient. The differences between regular and irregular waves are also investigated by means of theoretical and experimental results. It is found that the minimum reflection coefficient of irregular waves is larger than that of corresponding regular waves, but the contrary is the case for the maximum reflection coefficient. 相似文献
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The study investigates the effect of the salinity gradient on the functional composition, functional diversity and functional redundancy of soft-bottom communities in the south-western Baltic Sea. For this purpose, three different areas were selected and compared using a biological trait approach. Functional diversity was calculated by using Rao's Quadratic Entropy as a measure and functional redundancy by the ratio between functional and species diversity.Despite a high variability due to different other occurring environmental gradients, a clear shift in functional composition was visible using the BTA approach. The changes were most distinct for the traits, longevity and larvae type if the analyses were based on the biomass of the species, whereas abundance-based analyses tend to show less clear results.Along the same gradient, functional diversity and functional redundancy tended to increase if biomass data were used in the analysis. On the other hand no changes could be observed in the functional diversity when the abundance of the species was used.The result of the BTA showed a trend from long-lived and highly specialised species towards short-lived ubiquitous species with decreasing salinity. However, dominance of ubiquitous species in brackish waters seems to buffer the functional loss. Therefore it can be followed that by gaining functional redundancy the robustness of the benthic ecosystem to environmental changes increases. 相似文献
14.
光和温度对叶绿素a和脱镁叶绿酸a降解的影响 总被引：6，自引：0，他引：6
叶绿素a（Chlorophylla）常被用做浮游植物生物量的指标,是海洋常现调查项目内容。叶绿素a并不稳定,它在高温或有光的条件下发生降解,影响了对其浓度的测定。本文研究了温度和光线对纯叶绿素a及其降解产物脱镁叶绿酸a（Phaeopharbidea）降解速度的影响,以期对在提取过程中减少叶绿素a的降解有所帮助。1村料和方法1.1材料叶绿素a：使用Sigma产品（安瓿瓶1mg装）。用90％丙酮溶解,稀释成一定浓度,－20℃黑暗中保存备用。脱镁叶绿酸a：将少许10％盐酸加入叶绿素a即为脱镁叶绿酸a。光照度计：北京师范大学光电仪器厂生产的ST-92型光照度… 相似文献
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The reflection of regular and irregular waves from a partially perforated caisson breakwater with a rock-filled core is examined. The present mathematical model is developed by means of the matched eigenfunction method. Numerical results of the present model are compared with the experimental data of different researchers. Numerical examples are given to examine the effect of rock fill on the reflection coefficient. The differences between regular and irregular waves are also investigated by means of theoretical and experimental results. It is found that the minimum reflection coefficient of irregular waves is larger than that of corresponding regular waves, but the contrary is the case for the maximum reflection coefficient. 相似文献
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《African Journal of Marine Science》2013,35(1):1069-1077
The current fisheries management regime in New Zealand involves a system of quota management within which individual quotas are owned by fishermen and are transferable on an open market. The sum of these individual transferable quotas ITQs for a particular species equates to the total allowable catch TAC for that species. The objectives, implementation and consequences of this system are outlined, and its significance for stock assessment for species included in the ITQ system is discussed. A recent need for a TAC reduction in the deep-water fishery for orange roughy Hoplostethus atlanticus is mentioned in the context of the ITQ system. It is suggested that there is potential for economic benefit to the fishing industry in the Benguela system if an ITQ system were to be introduced locally. 相似文献
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《海洋气象学报》2015,(3)
选取1971—2013年枣庄国家一般气象站逐日最低气温资料,采用线性倾向估计法和异常霜冻指标,分析了枣庄站霜冻的变化趋势和异常发生情况。结果表明:枣庄初霜冻日的线性倾向率约为1.5d/10 a,即约以1.5d/10 a的速度推后;终霜冻日的线性倾向率约为-4.9 d/10 a,即约以4.9 d/10 a的速度提前;无霜冻期的线性倾向率约为6.9d/10 a,即约以6.9d/10a的速度延长。年代际间的变化从20世纪80年代以后也表现为初霜冻开始的日期越来越晚,终霜冻结束的日期越来越早,无霜期表现为逐渐延长的特点。异常霜冻表现为:特早初霜冻和偏早初霜冻各年代均有发生,其中特早初霜冻发生频率为2.3%,偏早初霜冻发生频率为9.3%;特晚终霜冻和偏晚终霜冻主要发生在20世纪70年代,21世纪10年代各有一次,特晚终霜冻发生频率为7%,偏晚终霜冻发生频率为11.6%。 相似文献
19.
The reflection of regular and irregular waves by a partially perforated caisson breakwater on a step bed 总被引：2，自引：0，他引：2
This study examines the reflection of regular and irregular waves from a partially perforated caisson breakwater located on a step bed. The step bed is treated as an idealized rubble mound foundation. Based on the linear potential theory, an analytical solution is developed to calculate the reflection coefficient of the structure subjected to regular waves. The matched eigenfunction expansion method is used for the solution. The regular wave method is also extended to irregular waves using a linear transfer function. The calculated results obtained for limiting cases are exactly the same as corresponding results given by the previous researchers. The present predictions also agree well with experimental data in the published literatures. Numerical experiments are conducted to examine the variations of the reflection coefficient versus its main effect factors, and some interesting results are presented. 相似文献