GOCE卫星重力探测任务   总被引：1，自引：0，他引：1  

徐新禹  李建成  邹贤才  范春波  禇永海 《大地测量与地球动力学》2006,26(4):49-55

通过分析利用卫星观测技术恢复地球重力场的现状与不足,论述了实施GOCE任务———地球重力场和稳态海洋环流实验的必要性;并阐述了GOCE任务的发展历史及现状、基本特点、组成部分、重力梯度测量原理、数据处理过程、误差特性,以及该任务在固体地球物理学、大地测量学、海洋学、冰河学等地球物理相关科学领域中的应用。  相似文献   

A further investigation of the decadal variation of ENSO characteristics with instability analysis     

孟祥凤  吴徳星  林霄沛  兰健 《大气科学进展》2006,23(1):156-164

Based on instability theory and some former studies, the Simple Ocean Data Assimilation （SODA） data are analyzed to further study the difference between the propagation of the ENSO-related oceanic anomaly in the off-equatorial North Pacific Ocean before and after 1976. The investigation shows that after 1976 in the off-equatorial North Pacific Ocean, there is a larger area where the necessary conditions for baroclinic and/or barotropic instability are satisfied, which may help oceanic anomaly signals propagating in the form of Rossby waves to absorb energy from the mean currents so that they can grow and intensify. The baroclinic energy conversion rate in the North Pacific after 1976 is much higher than before 1976, which indicates that the baroclinic instability has intensified since 1976. Prom another perspective, the instability analysis gives an explanation of the phenomena that the ENSO-related oceanic anomaly signal in the North Pacific has intensified since 1976.  相似文献   

北太平洋冬季环境背景场分析及优选航线     

黄彬  张增海  孙明华 《气象科技》2008,36(5):622-626

根据船舶气象导航的原理以及影响航线设计的各种因素,通过对北太平洋冬季大气和海洋环境背景的特征分析,指出船舶在设计航线时,应根据气候状况、海洋环境、天气形势分析结合中短期预报充分利用有利的风、浪、流等天气和海洋条件优选航线,不仅可以规避恶劣天气、确保航行安全,而且大大节约海运时间、降低航运成本.  相似文献   

青藏高原东北缘早古生代造山系中前寒武纪微陆块的再认识——兼谈原特提斯洋的起源   总被引：1，自引：0，他引：1  

张建新  路增龙  毛小红  滕霞  周桂生  武亚威  郭祺 《岩石学报》2021,37(1):74-94

在青藏高原东北缘的祁连-阿尔金-昆仑早古生代造山系中,夹杂有一些前寒武纪大陆块体,这些地块的组成、性质和演化既蕴含有超大陆聚散的重要信息,也对原特提斯体系的洋陆格局、造山类型和造山机制有重要启示意义.本文综合近年来这些前寒武纪微陆块的研究进展,结合我们所获得的新的研究资料,梳理了这些前寒武纪微陆块变质基底的岩石组成、构...  相似文献   

西北太平洋温带气旋爆发性发展的热力-动力学分析   总被引：8，自引：4，他引：4  

黄立文  仪清菊  秦曾灏  宇如聪 《气象学报》1999,57(5):581-592

利用天气、位涡分析和导出的Lagrangian型广义Z－O发展方程的诊断分析,考查了两个西北太平洋温带气旋爆发件发展的主要强迫机制和热力一动力空;司结构。结果表明,热力强迫对爆发性气旋发展起主要控制作用,当反映大气斜乐性的Laplacian温度平流、积云对流和湍流加热为主的热力强迫共同作用使地转相对涡度急剧增长时,气旋便出现了爆发性发展,其中积二尺度的对流加热贡献更大。Laplacian绝热冷却、大气向海洋的感热输送和摩擦效应起阻滞发展的作用,也是控制气旋衰亡的主要过程。爆发性发展启动同子因例而异,涡度平流、Laplacian温度平流和Laplacian大尺度加热均可成为主要启动因子。垂直积分平均分布和垂直结构考查进一步佐证了诊断分析的结果,并揭示了气旋爆发性发展过程中一些重要的热力-动力学分布特征。  相似文献   

论厦门海洋经济的持续发展   总被引：1，自引：1，他引：0  

杨圣云  周秋麟  郭允谋 《台湾海峡》1999,18(3):347-354

本文回顾了厦门海洋经济发展的历史,评述厦门海洋经济发展的现状和趋势,认为厦门已经形成了沿海城市经济、已经具有相当完备的海洋经济体系,但传统产业依然占据较大的比重,新兴产业还处于起步阶段,未来产业基本空白,城市经济的发展与海洋资源的利用结合不够紧密。海洋资源的开发利用尚为粗放式,科技进步的贡献率在海洋增长中不够大。海洋经济未走上开发和保护相结合的可持续发展道路。在发展重点海洋产业中,必须树立“科技兴  相似文献   

东太平洋海盆430柱沉积物特征与地层     

沈华悌 《海洋学研究》1999,17(3):1-8

对东太平洋海盆 ４３０ 柱沉积物的组分、古生物、结构构造以及古地磁、铀系等进行研究后, 将沉积物进行分类、命名与分层, 并确定其年代。研究表明, 本柱由下至上的沉积物分别为含沸石粘土、深海粘土、硅质粘土和钙质粘土。该柱中存在 ４ 个沉积间断, 其中在 ３２５ ｃｍ附近层位有一厚约 １０ ｃｍ 的多金属结核层,此界面为中中新世至晚上新世的沉积间断,它在 Ｃ Ｃ区内普遍存在, 持续时间长, 分布范围广。反映此时南极底层流十分强盛, 对东太平洋 Ｃ Ｃ 区的沉积作用和多金属结核形成与发育产生重要的影响。  相似文献   

Development of northwest Pacific guyots: General results from Ocean Drilling Program legs 143 and 144   总被引：1，自引：0，他引：1  

Peter Flood 《Island Arc》1999,8(1):92-98

Results of the Ocean Drilling Program legs 143 and 144, which investigated the nature and origin of seven guyots in the northwest Pacific Ocean, document a history of prolonged volcanism (128–84 Ma), followed by subsidence, accumulation of shallow-water carbonates, emersion following a sea-level fall, then continued subsidence, and drowning. Generally, the life span of a guyot is of the order of 5–20 million years. The stratigraphic sequence in each guyot consists of 3–10 m-thick, shoaling-upward cycles, which display a 100-Ka periodicity perhaps related to sea-level fluctuations. The drilling results indicate that the demise of the shallow-water carbonate platforms is related to either a temporal (110–100 Ma) event or paleolatitude location (0–10°S) involving nutrient-rich water not conducive to production of calcium carbonate by shallow-water organisms. Following emergence and erosion, re-submergence occurred during a rise of sea-level. However, the rate of sediment accumulation was unable to keep pace with the rate of sea-level rise and the guyots drowned. Subsidence continued as the lithospheric plate cooled. The majority of guyots are now at ~ 1500 m below sea-level. Plate movements over the past 100 million years have carried the guyots from ~ 14°S to their current location in the northwest Pacific. Guyots are flat-topped submerged volcanic islands capped by thick sequences of shallow-water carbonates. The flat-top morphology is constructional, not related to wave planation as originally thought and reported in most textbooks.  相似文献   

西太平洋富钴结壳元素组合特征及其地质意义   总被引：10，自引：0，他引：10  

何高文  薛婷  孙晓明  张学华  朱克超  王生伟 《矿物岩石地球化学通报》2005,24(2):125-129

海山富钴结壳是一种重要的海底固体矿产。对西太平洋海山的56个结壳样品进行了23种化学组分分析,并利用R型聚类分析和R型因子分析,分别提取四组元素组合和四个主因子。综合特征表明．富钴结壳在形成过程中,经历了一次强度较大的锰矿物相成矿作用,Co、Ni等元素的富集与此有关;铁矿物相的成矿作用强度较小,但表现出多期次的特点;锰、铁矿物是不同成矿作用的产物;结壳形成过程中,可能遭受了二次磷酸盐化作用,结壳中磷酸盐矿物的形成对铁矿物相的形成可能有抑制作用。  相似文献   

High‐order adaptive optical system for Big Bear Solar Observatory     

L.V. Didkovsky  C. Denker  P.R. Goode  H. Wang  T.R. Rimmele 《Astronomische Nachrichten》2003,324(4):297-298

A high‐order Adaptive Optical (AO) system for the 65 cm vacuum telescope of the Big Bear Solar Observatory (BBSO) is presented. The Coudé‐exit of the telescope has been modified to accommodate the AO system and two imaging magnetograph systems for visible‐light and near infrared (NIR) observations. A small elliptical tip/tilt mirror directs the light into an optical laboratory on the observatory's 2^nd floor just below the observing floor. A deformable mirror (DM) with 77 mm diameter is located on an optical table where it serves two wave‐front sensors (WFS), a correlation tracker (CT) and Shack‐Hartman (SH) sensor for the high‐order AO system, and the scientific channels with the imaging magnetographs. The two‐axis tip/tilt platform has a resonance frequency around 3.3 kHz and tilt range of about 2 mrad, which corresponds to about 25″ in the sky. Based on 32 × 32 pixel images, the CT detects image displacements between a reference frame and real‐time frames at a rate of 2 kHz. High‐order wave‐front aberrations are detected in the SH WFS channel from slope measurements derived from 76 sub‐apertures, which are recorded with 1,280 × 1,024 pixel Complex Metal Oxide Semiconductor (CMOS) camera manufactured by Photobit camera. In the 4 × 4 pixel binning mode, the data acquisition rate of the CMOS device is more than 2 kHz. Both visible‐light and NIR imaging magnetographs use Fabry‐Pérot etalons in telecentric configurations for two‐dimensional spectro‐polarimetry. The optical design of the AO system allows using small aperture prefilters, such as interference or Lyot filters, and 70 mm diameter Fabry‐Pérot etalons covering a field‐of‐view (FOV) of about 180″ × 180″.  相似文献