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131.
预估修正法对河口海岸海洋模式稳定性的提高   总被引:4,自引:0,他引:4  
河口海岸海洋模式时间差分为欧拉前差格式,在涡动粘滞系数较小的情况下,模式存在着弱不稳定性。为提高模式的稳定性,采用预估修正法对模式中科氏力项作半隐式处理。首先在理论上证明了模式稳定性的提高,随后设计一个高分辨率网格,考虑实际岸线和水深、边界通量、密度梯度力和风应力,把模式应用于冬季渤、黄、东海环流的数值模拟,数值试验也证明了模式稳定性的提高。改进后的河口海岸海洋模式较成功地模拟出了冬季渤、黄、东海环流(黑潮、台湾暖流、对马暖流、黄海暖流和沿岸流),与实际观测和研究结果较为一致。  相似文献   
132.
In order to trace their feeding habits, stable carbon and nitrogen isotope ratios (delta15N and delta13C), as well as trace metal concentrations (Zn, Cd, Fe, Cu, Se and Hg) were analysed in the tissues of five commercial shark species from the Celtic Sea: the tope shark Galeorhinus galeus, the black-mouthed catshark Galeus melastomus, the starry smooth hound Mustelus asterias, the spiny dogfish Squalus acanthias and the lesser-spotted dogfish Scyliorhinus canicula. Our results were compared to previously described stomach contents and isotopic composition of potential preys. Isotopic ratio delta15N suggested that tope sharks fed at a higher trophic level (16.7 per thousand in the muscle) than the other species, reflecting its piscivorous diet. The lower values of spiny dogfish (11.6 per thousand in the muscle) might be explained, amongst other things, by either its migratory behaviour or its preference for preys from lower trophic levels. Cd and Hg were correlated with isotopic ratios delta13C and delta15N, and were shown to be diet-related whereas Zn, Fe and Cu seemed much more linked to species-specific metabolism. Although this multidisciplinary approach is revealed as a useful tool for the study of shark ecology, the lack of known trophic fractionation suggests that isotopic data be compared to traditional diet analyses.  相似文献   
133.
于1991-1995年,运用数据库管理系统调用地理信息系统,图象处理信息系统等计算机技术,将我国海域内已查明的1000余种双壳类动物以数据库的形式进行管理,本数据库管理系统由查询,修改、统计、打印和绘图5个子系统构成,子系统之间以层次控制管理为主。为生物学研究和科学管理实现现代化进行探索。  相似文献   
134.
135.
The Arctic Ocean-Nordic Seas thermohaline system   总被引:2,自引:0,他引:2  
  相似文献   
136.
Time-series of remotely sensed distributions of phytoplankton, sea ice, surface temperature, albedo, and clouds were examined to evaluate the variability of environmental conditions and physical forcing affecting phytoplankton in the Beaufort and Chukchi Seas. Large-scale distributions of these parameters were studied for the first time using weekly and monthly composites from April 1998 to September 2002. The basic data set used in this study are phytoplankton pigment concentrations derived from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), ice concentrations obtained from the Special Sensor Microwave Imager (SSM/I) and surface temperature, cloud cover, and albedo derived from the Advanced Very High Resolution Radiometer (AVHRR). Seasonal variation of ice cover was observed to be the dominant environmental factor as the ice-edge blooms followed the retreating marginal ice zones northward. Blooms were most prominent in the southwestern Chukchi Sea, and were especially persistent immediately north of the Bering Strait in nutrient-rich Anadyr Water and in some fronts. Chlorophyll concentrations are shown to increase from a nominal value during the onset of melt in April to a maximum value in mid-spring or summer depending on location. Large interannual variability of ice cover and phytoplankton distributions was observed with the year 1998 being uniquely associated with an early season occurrence of a massive bloom. This is postulated to be caused in part by a rapid response of phytoplankton to an early retreat of the sea-ice cover in the Beaufort Sea region. Correlation analyses showed relatively high negative correlation between chlorophyll and ice concentration with the correlation being highest in May, the correlation coefficient being −0.45. 1998 was also the warmest in the 5 years globally and the sea-ice cover was least extensive in the Beaufort/Chukchi Sea region, partly because of the 1997–1998 El Niño. Strong correlations were noted between ice extent and surface temperature, the correlation coefficient being highest at −0.79 in April, during the onset of the bloom period.  相似文献   
137.
中国海域及邻区某些盆地生油岩的有机地球化学特征   总被引:1,自引:0,他引:1  
本文根据有机地球化学资料,研究和探讨了中国海域及邻区某些盆地生油岩的有机质丰度、可溶有机质的组成特征和不溶有机质的性质。结果表明,绝大多数生油岩有机碳含量大于0.90%,氯仿沥青“A”含量平均值大于600ppm,总烃大于200ppm。母质类型为腐殖—腐泥型和腐泥—腐殖型。  相似文献   
138.
Shelf break systems are highly dynamic environments. However little is known about the influence that benthic interactions and water mass mixing may have on vertical distributions of iron in these systems. Dissolved Fe (< 0.4 μm) concentrations were measured in samples from nine vertical profiles across the upper slope (150–2950 m water depth) at the Atlantic Ocean–Celtic Sea shelf break. Dissolved iron concentrations varied between less than 0.2 and 5.4 nM, and the resulting detailed section showed evidence of a range of processes influencing the Fe distributions. The near sea floor data were interpreted in terms of release and removal processes. The concentrations of dissolved Fe present in near seabed waters were consistent with release of Fe from in situ remineralisation of particulate organic matter at two upper slope stations, and possibly release from pore water upon resuspension on shelf. Lateral transport of dissolved iron was evident from elevated Fe concentrations in an intermediate nepheloid layer and its advection along isopycnals. Surface waters at the shelf break also showed evidence of vertical mixing of deeper iron-rich waters. These waters contained macronutrients that sustained primary productivity in these otherwise nutrient-depleted surface waters. The data also suggest some degree of stabilisation of relatively high concentrations of iron, presumably through ligand association or as colloids. This study supports the view that lateral export of dissolved iron to the interior of the ocean from shelf and coastal zones and may have important implications for the global budget of oceanic iron.  相似文献   
139.
白令海和楚科奇海表层沉积中的有孔虫及其沉积环境   总被引:5,自引:3,他引:5  
通过对白令海和北冰洋楚科奇海39个表层沉积样品中有孔虫的定量分析,发现表层沉积中浮游有孔虫稀少可能与该区表层生产力低、碳酸盐溶解作用较强有关,而底栖有孔虫的分布则主要受表层初级生产力以及与水深相关的碳酸盐溶解作用和水团性质所控制,其中北冰洋楚科奇海陆架区有孔虫以Elphidium spp.组合和Nonionella robusta组合为主,丰度和分异度低,受北冰洋沿岸水团控制;白令海陆坡区有孔虫以Uvigerina peregrina-Globobulimina affinis组合为主,含N.robusta较多,丰度和分异度相对高,受太平洋中层和深层水团控制,但该区碳酸盐溶跃层和补偿深度(CCD)相对浅,约分别位于2000和3800m处.此外,白令海陆坡上部表层沉积中含有北冰洋陆坡区典型深水底栖有孔虫种Stetsonia arctica,说明白令海峡两侧的海区曾有深部水交流.  相似文献   
140.
大洋钻探与中国边缘海沉积地质学   总被引:3,自引:0,他引:3  
石学法 《海洋科学》1996,20(3):47-50
边缘海沉积地质学研究在大洋钻探计划中占据着重要地位,也是我国的优势所在,应该成为我国ODP近期工作的主要内容。本文讨论了与ODP有关的几个中国边缘海沉积地质学问题:古黑潮的演变与陆海相互作用,长江、黄河入海时间及其对海洋沉积作用的影响,冲绳海槽的沉积相和沉积体系,古季风与海平面变化,这些问题的深入研究与解决将会为实现ODP的学术目标,为全球变化研究做出重要贡献。  相似文献   
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