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51.
52.
基于POM模式的"blending"同化法,构建了天津港及附近海域分辨率为1'×1'、13个主分潮的精密潮汐模型。构建过程中重点关注水深数据格网化与潮汐模型的精度评估。水深数据格网化过程基于尽量扩大覆盖范围、分辨率与水深数据相匹配以及保持岸线形状基本不变等原则。潮汐数值模拟过程采用分批同化T/P点与验潮站,实现对潮汐模型精度的可靠评估。经估计,在天津港附近的9个主分潮RSS在10cm内。 相似文献
53.
Abstract. In order to evaluate the effect of epibenthic suspension-feeding organisms on nepheloid-layer processes, a novel flow-through 'Benthic Ecosystem Tunnel' was used on sublittoral marine sediment substrate. Our test organism was the ascidian Microcosmus sulcatus . Particle and chlorophyll a reduction were recorded. The correlation of seasonal fluctuations of chlorophyll a concentrations with chlorophyll a reduction by M. sulcatus indicates the potential for Microcosmus to control local phytoplankton input to the subtidal nepheloid layer. However, the relatively low density of Microcosmus at the study site, the nature of the sediment surface and the susceptibility of ascidians to high turbidity ( i.e. , high sedimentation rates of total particular matter (TPM) causing frequent periods of siphon closure and inactivity) makes it unlikely that M. sulcatus is an important element controlling the composition of the nepheloid layer on a large scale. 相似文献
54.
Jiabin Zhou Tieguan Wang Yanping Zhang Ningning Zhong Patricia M. Medeiros Bernd R.T. Simoneit 《Atmospheric Research》2009,93(4):849-861
The solvent-extractable organic compounds of atmospheric PM10 samples, collected over two years beginning in 2003 at urban and suburban sites of Beijing, were characterized using gas chromatography–mass spectrometry (GC–MS). The elemental carbon (EC) contents were determined and ranged from 4.3 to 42 μg m− 3. Organic compounds in total extracts were identified and included unresolved complex mixture (UCM) and series of n-alkanes, n-alkanols, n-alkanoic acids, polycyclic aromatic hydrocarbons (PAHs); saccharides, alkanedioic acids, steroids, and other biomarkers and source tracers. The seasonal variations of their relative abundances are discussed. The abundance order for the major molecular classes in the particulate organic matter (POM) was the following: UCM > saccharides > n-alkanoic acids >n-alkanes > n-alkanols > PAHs > hydroxy-PAHs > other biomarker tracers. Based on the genetic significance of the molecular tracers, the dominant sources of POM are proposed for the two sampling sites. The emissions from fossil fuel use (both coal and petroleum products), biomass combustion, other pyrolysis sources, higher plant wax, and secondary products contribute > 98.0% of the POM mass. The fossil fuel use (average = 65% of POM) is the largest contributor and derives mainly from vehicular traffic. 相似文献
55.
56.
Franois Charles Susanna Lopez-Legentil Antoine Grmare Jean Michel Amouroux Martin Desmalades Gilles Vtion Karine Escoubeyrou 《Continental Shelf Research》2005,25(19-20):2533
Environmental parameters and gross sedimentation rates (GSR) were monitored at a fixed site located in the Bay of Banyuls-sur-Mer (NW Mediterranean), between March 1997 and April 1998, together with the main biochemical characteristics of both sedimenting and sedimented particulate organic matter (POM). Three storms which occurred during this time period resulted in natural sediment resuspension. This is indicated by the corresponding increase in GSR and a decrease in the enzymatically hydrolysable amino acids/totally hydrolysable amino acids ratio (EHAA/THAA), within the sedimenting POM. Only the strongest storm resulted in (1) a transitory increase in fine-grained particles, (2) concomitant increases in organic carbon, carbohydrates, lipids and THAA, and (3) a decrease in the EHAA/THAA ratio in surficial sediments. For most of the assayed parameters, the values recorded after the December 1997 storm corresponded to extremes for the whole period under study. This emphasises the role of storms in controlling the characteristics of sedimented and sedimenting POM.Ten sediment types, with contrasting biochemical characteristics, were selected for experiments; these were based on the results of the monitoring survey and were used during adsorption and absorption experiments involving 14C tetrachlorobiphenyl (TCB). Adsorption rates differed significantly between the sediment types, but did not correlate with any of the assayed biochemical parameters. Absorption efficiency by the mussel Mytilus galloprovincialis also differed between the sediment types; it correlated positively with all the assayed biochemical parameters, except lipids. Comparison between the magnitudes of the increase in GSR, together with the decrease in absorption efficiency during resuspension events, suggests that resuspension tends to enhance the transfer of organic pollutants in the benthic food chain. 相似文献
57.
Nozomi Ytow Motoo Utsumi Humitake Seki 《Aquatic Sciences - Research Across Boundaries》1996,58(2):91-102
Ultraviolet (UV) spectra were measured to characterize the dissolved and particulate organic matter in a bog and to investigate the seasonal fluctuation of this organic matter. The optical density spectra in the UV region of dissolved organic matter (DOM) were proportional to
–4, where is the wavelength of incident light. There was also small absorption on the
–4 spectra. The optical density at a wavelength of 280 nm was proportional to the concentration of dissolved organic carbon (DOC). The spectra and the dependency of optical density on DOC did not vary throughout the investigation period. The UV spectra of acid extractions of particulate organic matter (POM) showed two absorption peaks at the wavelengths of 220 nm and 335 nm. These peaks are well represented by the sum of two Lorentz functions. The ratio of the absorbances,A
280/A
335, was dependent on the nitrogen/carbon ratio of POM and the chlorophyll fraction in particulate organic carbon (POC), and not dependent on POC itself. The dependency of POC absorption at 280 nm varied with this ratio which fluctuated seasonally. 相似文献
58.
海浪混合参数化的渤海、黄海、东海水动力环境数值模拟 总被引:9,自引:2,他引:9
在浪-流耦合的概念下,对Princeton Ocean Model(POM)模式进行改进,增加特征波参数下的海浪混合作用,并把潮流和环流同时模拟,得到了渤海、黄海、东海典型的环流和水文特征,特别是夏季黄海的温跃层现象,夏季长江冲淡水扩展路径以及我国东部海域冬季和夏季典型环流等.研究表明,海浪的作用使海洋上层混合得更均匀,潮流的作用使海洋底层混合得更均匀,二者是温跃层形成的重要原因;考虑潮效应模拟流场,由于潮扩散和潮余流的作用,长江冲淡水路径与实际观测更为符合. 相似文献
59.
SU Jie * WU Huiding ZHANG Yunfei LIU Qinzhen BAI Shan. Key Laboratory of Physical Oceanography of State Education Ministry Marine Environment College OceanUniversity of China Qingdao China. First Institute of Oceanography State Oceanic Administration Qingdao China. National Marine Environment Forecast Center Beijing China 《海洋学报(英文版)》2004,(4)
1 IntroductionAs an important compartment of global cli-mate system, the development and variation ofsea ice directly affect the global atmosphere andocean environment, especially the deep watersformation and circulation. Therefore, it be-comes one of the keys of the global climatestudy to explore the coupling physical processof sea ice to atmosphere and ocean in the cli-mate system and to set up the global coupledairiceocean system. The studies on the in-teraction of iceocean and its coupled… 相似文献
60.
The coupled ice-ocean model for the Bohai Sea is used for simulating the freezing, melting, and variation of ice cover and the heat balance at the sea-ice, air-ice, and air-sea interfaces of the Bohai Sea during the entire winter in 1998~1999 and 2000~2001. The coupled model is forced by real time numerical weather prediction fields. The results show that the thermodynamic effects of atmosphere and ocean are very important for the evolvement of ice in the Bohai Sea, especially in the period of ice freezing and melting. Ocean heat flux plays a key role in the thermodynamic coupling. The simulation also presents the different thermodynamic features in the ice covered region and the marginal ice zone. Ice thickness, heat budget at the interface, and surface sea temperature, etc. between the two representative points are discussed. 相似文献