共查询到20条相似文献，搜索用时 31 毫秒
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D. Shepherd D. Burgess T. Jickells J. Andrews R. Cave R.K. Turner J. Aldridge E.R. Parker E. Young 《Estuarine, Coastal and Shelf Science》2007,73(3-4):355-367
A hydrodynamic model is developed for the Blackwater estuary (UK) and used to estimate nitrate removal by denitrification. Using the model, sediment analysis and estimates of sedimentation rates, we estimate changes in estuarine denitrification and intertidal carbon and nutrient storage and associated value of habitat created under a scenario of extensive managed realignment. We then use this information, together with engineering and land costs, to conduct a cost benefit analysis of the managed realignment. This demonstrates that over a 50–100 year timescale the value of the habitat created and carbon buried is sufficient to make the large scale managed realignment cost effective. The analysis reveals that carbon and nutrient storage plus habitat creation represent major and quantifiable benefits of realignment. The methodology described here can be readily transferred to other coastal systems. 相似文献
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Statistical relations of the run-up height of Tsunami waves to the distance and energy of the source
A statistical analysis of the relation between the run-up height of historical tsunami events and the distance and magnitude of the source was performed on the basis of the known Historical Tsunami Data Base [5]. The sample from the database used for the analysis comprises 5638 run-ups caused by 628 seismic events. This analysis, together with the dimensionality theory, shows that the statistical average of the run-up height is inversely proportional to the distance from the source to a power close to 1/2 (that is characteristic of the cylindrically symmetrical case) and directly proportional to the 3/8 power of the earthquake energy. 相似文献
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A. R. Lupo I. I. Mokhov S. Dostoglou A. R. Kunz J. P. Burkhardt 《Izvestiya Atmospheric and Oceanic Physics》2007,43(1):45-51
It was shown that abrupt changes in the large-scale structure of atmospheric flows may lead to the rapid decay of blocking. Analysis of phase diagrams made it possible to identify when sharp changes occurred in the dynamics of the system. The connection of these changes to the decay of blocking was estimated for three blocking events in the Southern Hemisphere. In addition to phase diagrams, enstrophy was used as a diagnostic tool for the analysis of blocking events. From the results of this analysis, four scenarios for the decay mechanisms were determined: (i) decay with a lack of synoptic-scale support, (ii) decay with an active role for synoptic processes, and (iii–iv) either of these mechanisms in the interaction with an abrupt change in the character of the planetary-scale flow. 相似文献
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Nicolas Mazzella Josiane Molinet Agung Dhamar Syakti Jean-Claude Bertrand Pierre Doumenq 《Marine Chemistry》2007,103(3-4):304-317
This in situ study reports on the relevance of intact phospholipids as new biomarkers and highlights the limits of the classical fatty acid analysis after the hydrolysis of the polar lipid fraction. The analysis of polar lipid fractions revealed significant contributions of marine macrophytes with either non-phospholipid compounds (sulfoquinovosyl diacylglycerol) or with both non-bacterial phospholipid classes (phosphatidylcholine) and non-bacterial phospholipid molecular species (some molecular species of phosphatidylglycerol). The analysis of intact phospholipids showed also the predominance of gram-negative bacteria in sediments whereas the analysis of fatty acids alone cannot confirm such information. Lastly, as regard to the effects of petroleum hydrocarbons on the sedimentary bacterial communities, we observed a higher degree of saturation of the fatty acyl chains of the phospholipids extracted from sediment exposed to a massive and chronic crude oil contamination. Such a result was interpreted as an adaptive response resulting in higher membrane rigidity of the bacterial communities. 相似文献
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Izvestiya, Atmospheric and Oceanic Physics - We have mapped a short-period S-wave attenuation field of in the lithosphere of the Caucasus. We have used a method based on the analysis of the ratio... 相似文献
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Based on monthly mean Simple Ocean Data Assimilation(SODA) products from 1958 to 2007,this study analyzes the seasonal and interannual variability of the North Equatorial Current(NEC) bifurcation latitude and the Indonesian Throughflow(ITF) volume transport. Further,Empirical Mode Decomposition(EMD) method and lag-correlation analysis are employed to reveal the relationships between the NEC bifurcation location,NEC and ITF volume transport and ENSO events. The analysis results of the seasonal variability show that the annual mean location of NEC bifurcation in upper layer occurs at 14.33°N and ITF volume transport has a maximum value in summer,a minimum value in winter and an annual mean transport of 7.75×106 m3/s. The interannual variability analysis indicates that the variability of NEC bifurcation location can be treated as a precursor of El Ni?o. The correlation coefficient between the two reaches the maximum of 0.53 with a time lag of 2 months. The ITF volume transport is positively related with El Ni?o events with a maximum coefficient of 0.60 by 3 months. The NEC bifurcation location is positively correlated with the ITF volume transport with a correlation coefficient of 0.43. 相似文献
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We discuss the results of analysis of published data and field and laboratory investigations aimed at the solution of the
problem of comparabilityof the results of detection of hydrogen sulfide in the Black Sea by spectrophotometric and iodometric
methods. We show that the reproducibility of the results of spectrophotometric analysis is higher than hat of the iodometric
method only in the case where the content of sulfide in a sample is less than 10–30 μMl−1. When larger concentrations are involved, the traditional iodometric analysis proves to be the most precise and reliable
method for the detection of hydrogen sulfide in the Black-Sea waters.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
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A method that can monitor the density of zooplankton at an adequate spatio-temporal resolution is desired in oceanic ecosystem research. To address this need, we have developed a submersible microscope equipped with a noninterlace CCD camera. The target plankton for this microscope includes Copepoda, Ploima, and Ciliata, which are dominant species in the coastal waters around Japan. In addition, the requirements of systems for underwater imaging of zooplankton are discussed. The key issues investigated for their possible influence on system performance are lens selection, camera selection, and method of illumination. Higher order local autocorrelational (HLAC) masks are used to extract features from images. Combining these features with multivariate analysis, which is a two-step feature extraction method, results in a powerful tool for extracting general information from images. In our procedures, a set of these features provides a 33-dimensional vector. To identify and count zooplankton, canonical correlation analysis and discrimination analysis are performed. This allows zooplankton to be counted and classified into taxonomic units. Another canonical correlation analysis was made for the sizing of the plankton. Proof of the principle experiment is obtained with images of both preserved and living Copepoda 相似文献
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A. A. Zelenko R. M. Vil’fand Yu. D. Resnyanskii B. S. Strukov M. D. Tsyrulnikov P. I. Svirenko 《Izvestiya Atmospheric and Oceanic Physics》2016,52(4):443-454
A new version of the ocean data assimilation system (ODAS) developed at the Hydrometcentre of Russia is presented. The assimilation is performed following the sequential scheme analysis–forecast–analysis. The main components of the ODAS are procedures for operational observation data processing, a variational analysis scheme, and an ocean general circulation model used to estimate the first guess fields involved in the analysis. In situ observations of temperature and salinity in the upper 1400-m ocean layer obtained from various observational platforms are used as input data. In the new ODAS version, the horizontal resolution of the assimilating model and of the output products is increased, the previous 2D-Var analysis scheme is replaced by a more general 3D-Var scheme, and a more flexible incremental analysis updating procedure is introduced to correct the model calculations. A reanalysis of the main World Ocean hydrophysical fields over the 2005–2015 period has been performed using the updated ODAS. The reanalysis results are compared with data from independent sources. 相似文献
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渤海南部沿岸水运移及渤黄海水体交换的季节变化 总被引：2，自引：0，他引：2
针对渤海及附近海区的曲折岸线变化以及水文资料时空分布不均匀性的特点,使用四维客观分析LOESS方法得到逐月气候态盐度场。结果表明:渤海南部沿岸水扩展和运移受季风影响显著。冬季沿岸水向渤海湾和莱州湾堆积,形成沿山东半岛龙口海岸东向爬行的水舌,该水舌在蓬莱水域向东扩展;夏季沿岸水向渤海中部冲溢,特别是在黄河口附近,其核心区厚度可达8 m,可扩展到119°30′E处,同时莱州湾内的沿岸水向湾内西部收缩。冬季渤海海峡呈现显著"北进南出"水交换态势;夏季渤海海峡定常流方式的水交换特征不明显。 相似文献
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The problem of recognition of algal genera based on the remote sensing data requires the analysis of the algae biomass’s distribution.
This study provides the analysis of the algae spatial and temporal variations in the Peter the Great Bay. While 116 algal
genera were observed, only a few genera have dominated. Usually, the dominant genus contributed about 60% of the sample’s
biomass (the minimal value is 20% usually) and 4 dominant genera contributed about 90% of the total phytoplankton biomass.
The effective scattering crosssection of the algae in the samples is very changeable and this feature looks promising for
the recognition problem. It was found that the spatial and temporal variations of the algal biomass are significant, but the
percentage characteristics of a few dominant genera are relatively stable with no significant dependence on a region and a
biomass value. The algae’s composition analysis has demonstrated that the same algal genera are propagated in different parts
of the Bay. For a given region and month, the set of algae dominated that constitutes about 90% of the monthly biomass is
rather small (not more than 10 genera usually). Most of the alga genera (∼75%) do not ever reach a mono domination state (more
than 50% of the sample’s biomass). 相似文献
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A Leeway-Trace model was established for the traceability analysis of drifting objects at sea. The model was based on the Leeway model which is a Monte Carlo-based ensemble trajectory model, and a method of realistic traceability analysis was proposed in this study by using virtual spatiotemporal drift trajectory prediction. Here,measured data from a drifting buoy observation experiment in the northern South China Sea in April 2019,combined with surface current data obtained from the finite volu... 相似文献
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Cluster analysis is discussed in the context of its application to map various test areas in the sea. By analysing the correspondence of the identified categories to areas with specific hydrological conditions, an attempt is made to relate the types of fine structure to diverse background conditions. With two test areas mapped, a conclusion is made as to the possible application of cluster analysis to this end.Translated by Vladimir A. Puchkin. 相似文献
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Joon-Sang An 《Marine Georesources & Geotechnology》2013,31(4):517-523
ABSTRACTAn evaluation of the stability of subsea tunnels during operation is very important considering the risks involved with subsea tunnels. Although a large volume of monitoring information can be obtained, back analysis has been performed based on the internal displacement. In this study, the efficiency of an estimation of the safety of an operating subsea tunnel has been improved by implementing the back analysis algorithm based on various monitoring information. The differential evolution algorithm was adopted for back analysis of an operating subsea tunnel. The differential evolution algorithm was improved to accommodate the multiple target variables for back analysis, such as the elastic modulus, cohesion, friction angle of the ground, and the time-dependent elastic modulus of concrete lining. In addition, the elastic modulus of the concrete lining and the properties of reinforced ground can be evaluated with the proposed algorithm using a range of monitoring data, such as the internal displacement and stress acting on the lining. In summary, back analysis with a differential evolution algorithm can be used to evaluate the stability of an operating subsea tunnel. 相似文献
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This paper presents measurements and analysis of fluid velocity within the context of spilling waves. The data have been collected using 2-D Laser Doppler Velocimetry in pre-breaking monochromatic waves generated in a wave tank. The analysis is performed using orthogonal wavelets and, in addition to the classical criterion adopted in applying Taylor's hypothesis, a new algorithm is proposed for the eduction of eddies at different length scales. The contribution of different scale vortices is computed, and phase is resolved. Microvortices (smaller than the breaker height but larger than the dissipative vortices) and mid-size vortices (with length ranging from the breaker height to the wave length) carry out most turbulence energy under wave crest. The phase average vorticity and strain rate is computed at different wave lengths, with the analysis of intermittence. The intermittency factor shows spikes in the wave crest, especially for turbulence in small vortices. 相似文献
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Section 57 of the Royal Decree of July 9, 1976 "relating to safe practice for the production, etc., of submarine petroleum resources," states that "the ministry may require that load-bearing structures shall be provided with instruments." Based on this section, the Norwegian Petroleum Directorate has issued "regulations for the recording and processing of E- and P-data." One aim of these regulations is to be a basis for collection and analysis of data of fixed installations (P-data) as well as data of the environment round the installations (E-data). The continuous recording of the different parameters, as required by the regulations, results in the accumulation of a tremendous amount of data. Further, the data must be verified, organized, and structured for later use in different types of calculations. A special organization and a data bank have been created to undertake the tasks of collecting the data from the installations, creating necessary tools (such as computer routines and programs) for receiving source data, and doing necessary analysis such as spectral analysis, stochastic dynamic behavior analysis, cumulative fatigue analysis, etc., and producing reports. Furthermore, an environmental center for E-data from the Norwegian continental shelf has been created and is being administrated by the Norwegian Meteorological Institute. Original E-data will be made publicly available upon request and data summaries and statistics will be published regularly. This data bank will also contain standard meteorological observations gathered on the continental shelf from ships, semi-submersibles, etc. 相似文献
