冰心中的气候环境记录与全球变化研究   总被引：1，自引：0，他引：1  

谢树成  殷鸿福 《海洋地质与第四纪地质》1997,17(4):109-113

冰心是高分辨地记录全球变化的主要信息载体之一。本文总结了冰心中提取古气候和古环境信息的系列记录，包括同位素、微量气体、阴阳离子、微粒、生物和有机质等。着重讨论了由这些记录提取的古气候和古环境变化方面的研究进展，并提出了今后的研究重点。  相似文献   

作用于平台桩腿的海冰屈曲破坏冰压力随机过程模型及其参数确定   总被引：2，自引：1，他引：2  

段忠东  欧进萍 《海洋工程》1996,(4)

冰对结构的作用过程是典型的随机过程。本文在冰压力过程为平稳过程的假设下，从渤海海冰对平台桩腿作用的大量实测冰压力数据中，选取了２１条冰屈曲破坏时的冰压力时程曲线，对它们进行谱分析后，得到了单点冰屈曲破坏的压力随机过程的谱密度，并确定了谱参数及其跟环境要素的关系，依据文献［１］中冰压力沿圆柱面的空间分布，建立了绕桩腿的冰压力随机场模型，并得到了作用于桩腿的总冰力随机过程及其谱密度。本文的研究成果为平台结构冰激随机振动和疲劳累积损伤分析提供了荷载基础  相似文献   

The status of geological dredging techniques     

R. B. Kidd  Q. J. Huggett  A. T. S. Ramsay 《Marine Geophysical Researches》1990,12(1-2):131-143

Scientific sea-floor dredging is currently used in marine geology primarily by the hard-rock community interested in the recovery of basement rock samples from the unsedimented deep ocean floor. The technique has generally been eclipsed by ocean drilling for recovery of sedimentary rocks, because of perceived uncertainties in the location of sampling and in the representativeness of recovered material. This contribution reviews dredging equipment currently in use by marine geological institutions and refers to pinger attachments that allow precise information on the behaviour of the dredge to be telemetered back to the ship. We argue that improvements in ship navigation and transponder navigation at the seafloor, when used in conjunction with surface and/or deeply towed sidescan and swathemapping surveys, now allow for considerably less uncertainty on the location of dredge sampling. Refined sorting criteria for dredge hauls are now also available. Recent comparisons of regional sample recovery by ocean drilling and by dredge sampling indicate that the dredge hauls can usefully supplement the drilling data in the construction of sedimentary and tectonic histories of seafloor areas.  相似文献   

Mechanisms controlling the temporal variation of the sea ice edge in the Southern Ocean     

Noriaki Kimura 《Journal of Oceanography》2007,63(4):685-694

This paper examines the mechanism controlling the short time-scale variation of sea ice cover over the Southern Ocean. Sea ice concentration and ice velocity datasets derived from images of the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager (SSM/I) are employed to reveal this mechanism. The contribution of both dynamic and thermodynamic processes to the change in ice edge location is examined by comparing the meridional velocity of ice edge displacement and sea ice drift. In the winter expansion phase, the thermodynamic process of new ice production off the ice edge plays an important role in daily advances of ice cover, whereas daily retreats are mostly due to southward ice drift. On the other hand, both advance and retreat of ice edges in the spring contraction phase are mostly caused by the dynamic process of the ice drift. Based on the above mechanism and the linear relation between the degree of ice production at the ice edge and northward wind speed, the seasonal advance of ice cover can be roughly reproduced using the meridional velocity of ice drift at the ice edge.  相似文献   

北极海冰变化特征分析   总被引：3，自引：0，他引：3  

魏立新  张占海 《海洋预报》2007,24(4):42-48

本文利用NASA的海冰密集度资料(时间为1978年10月～2002年9月,分辨率为1.0×0.25),计算并分析了1978～2002年的北极海冰面积、范围的时间变化趋势以及变化的空间分布。  相似文献   

南极普里兹湾气旋的生消发展   总被引：3，自引：4，他引：3  

解思梅  郝春江  梅山  刘克威  魏立新 《海洋学报》2002,24(6):11-19

利用1989～2000年现场观测的气象资料,特别是自1997年以来在南极考察船上接收的NOAA卫星极轨高分辨的卫星云图,研究了普里兹湾气旋的生消发展;提出了夏季绕极气旋进入普里兹湾内也会发展加强,在湾内东风带里也能生成气旋的新观点,修正了普里兹湾仅是气旋墓地的不全面说法,从而进一步完善了南极西风带绕极气旋和东风带上气旋生消发展的理论;研究了普里兹湾冰-气-海相互作用的机理,解释了气旋发生、发展的物理过程.用整体动力学输送法计算了进入普里兹湾980205号绕极气旋爆发性发展的能量交换,指出气旋在超过冰坝进入冰间湖可以获得巨大的热量,使气旋迅速发展成为具有南极特色的强风暴,风力达12级以上,平均风速为38m/s;瞬时最大风速达100m/s.  相似文献   

黄、渤海沿岸海冰测点代表性浅析     

彭垣 《海岸工程》1994,(4)

通过分析１９８０年以后的海冰资料和卫星云图照片，对黄、渤海沿岸１１个海冰测点的历史变迁进行了评述，浅析了测点的优劣及使用资料时应注意的事项。  相似文献   

中国南极中山锚地勘测     

冯守珍  徐承德 《海洋科学进展》1999,(4)

本文介绍了南极中山锚地的选择条件,勘测实施过程及水文、气象特点,并对测量区域作了分析研究与评价,科学地确定了适合科考船抛锚的锚地,致使“雪龙”船首次在中山锚地抛锚试抛成功,结束了中山站附近海域无锚地的历史。  相似文献   

分形分析方法在海冰趋势预测中的应用   总被引：1，自引：0，他引：1  

高振会  杨建强  费立淑 《海洋通报》2003,22(4):66-69

根据渤海北部1966——2001海冰冰级年际变化的实际资料，利用R／S分析的原理和方法计算了H指数，建立了R(i)/S(i)与i的关系式，对渤海北部海冰趋势进行了预测分析。结果表明，利用分形分析方法进行海冰趋势预测不仅方法简便，而且结论具有客观性，可以将其作为海冰趋势预测中较为有效的一种方法。  相似文献   

Nitrogen forms and decomposition of organic carbon in the southern Bohai Sea core sediments   总被引：5，自引：0，他引：5  

Song Jinming  Ma Hongbo  L&#; Xiaoxia 《海洋学报(英文版)》2002,21(1):125-133

Study on form characteristics of nitrogen in marine sediments is the primary method to research its biogeochemical cycling and nitrogen form characteristics in core sediments can reflect the process and results of early diagenesis in a certain degree. In this paper, Sequential extraction process in natural grain size was used for studying the existent forms of nitrogen in five core sediments of the southern Bohai Sea for the first time. Nitrogen was divided into two parts -transferable and fixed based on whether it could be extracted by the reagent. Distributions and early diagenesis of transferable nitrogen forms in the southern Bohai Sea were researched integratedly. Results indicate that IEF - N and OSF-N are predominant forms in transferable part in the studied core sediments. Contents of different nitrogen forms vary differently with depth, and have different diagenesis process. Decomposition constant of organic nitrogen (ON) and OC are about 15.51 × 10~(-3)a~(-1)and 4.79× 10~(-3)a~(-1) respective  相似文献