东海黑潮表层盐度分布特征及其影响因素     

任惠茹  康建成  李卫江  安琰  张建平  王甜甜 《热带海洋学报》2011,(5)

利用美国国家海洋大气管理局2007年发布的全球海域温、盐数据库资料,美国地球物理数据中心2006年发布的海底地形数据库资料以及日本海洋科学与技术机构2003年发布的1997—2002年东海地区月平均降水量资料,研究东海黑潮表层盐度的月季分布特征,并分析其影响因素。结果表明,东海黑潮表层盐度存在明显的月季变化特征。总体而言,12月至次年3月表层盐度高,6—9月表层盐度低,4、5月和10、11月为过渡阶段;表层盐度高值分布在东海黑潮主段靠近东边界一侧;6—9月入口段的表层盐度高于出口段的表层盐度,其他月份入口段的表层盐度低于出口段的表层盐度。东海黑潮表层盐度主要受表层温度、降水、径流的影响。冬、春、秋季的表层盐度分布在黑潮主段靠近陆架一侧区域受表层温度影响大;降水对东海黑潮表层盐度产生局部小范围的影响,时间主要集中在1月和6—8月份,区域分布在低纬25°N以南和30°N附近。长江冲淡水夏季对东海黑潮表层盐度的影响大于其他季节对东海黑潮表层盐度的影响,7月长江径流量达到最大值时,对应的黑潮扇形区的盐度最低。  相似文献   

Historic catches,abundance, and decline of Atlantic salmon Salmo salar in the River Elbe     

Christian Wolter 《Aquatic Sciences - Research Across Boundaries》2015,77(3):367-380

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辽宁沿海早、中期全新世海进中的一次海退事件探讨          下载免费PDF全文

方晶  武亚芳  李瑞武  周江  康玲玲  柴锐  马楠 《地学前缘》2009,16(2):396

通过分别对辽东半岛东侧大洋河平原中部的D65孔岩心做连续的硅藻分析,以及对辽东半岛西侧的长兴岛八岔沟古泻湖平原B3孔、下辽河平原的机械钻孔X33及手动钻孔X11和X21等钻孔岩心做连续的粘土混浊水电导率测定,得到各岩心的硅藻图谱/或粘土混浊水电导率图谱。显示出在这些海岸平原均有厚度在6m以上的海相层存在。表明全新世海侵时海水达到并长期占据这些海岸平原。同时还显示在这些海相地层的5～7m深处,普遍存在一层陆相或海陆交互相地层,通过对各地点已有的14C年代数据分析,推测这层陆相层或海陆交互相地层应该形成于全新世海面上升的早全新世—中全新世时期。表明全新世海进期当中,辽宁沿海普遍存在一次海退地质事件。从下辽河平原样品的14C测年数据,推测这次海退时期大致在9300～8000aB.P.(校正年)。  相似文献   

Midale油田奥陶系白云岩储层格架与油藏特征     

蒲仁海  卿海若 《沉积学报》2004,22(2):234-243

综合三维地震、钻井、岩心和薄片资料分析了该油藏的储层展布格架、油藏构造及演化、油藏类型和控制因素等。在钻井剖面对比图上依据密度和中子测井,将白云岩储层可划分为4个小层。第1、2小层由于位于圈闭构造的较高部位因而通常含油。第3、4小层可能由于在某处与第1、2小层连通,虽然也具低幅度构造和更大的厚度及孔隙度,但多为水层;又因其容易侧向尖灭,故有可能形成地层圈闭。三维地震解释和正演模型均表明,当第1、2小层较厚时,常对应于强振幅和高频反射;当第3、4小层较厚且4个小层并存时会在原储层反射位置下方多出一个波峰同相轴,而且第3、4小层的尖灭通常伴随着该同相轴的终止。这一点有助于寻找与第3、4小层上倾尖灭有关的圈闭。Midale油藏的空间分布受局部低幅度构造和储层小层发育状况的双重控制。油藏驱动机制可能为边水和底水两种类型的结合。根据地震剖面上的地层关系和由三维地震资料所做的古构造演化图来看,油藏低幅度构造的形成与后期地层在前寒武基岩古隆起上的披覆及该隆起在后期多次不整合发生期间的重新活动有关。圈闭雏形形成于早志留到中泥盆世,最终定型于晚白垩世。区域构造演化和油气运移研究表明,有利的油气聚集带位于某些靠近油源区的古鼻隆的东北翼。  相似文献   

A continuum representation of fracture networks. Part II: application to the Äspö Hard Rock laboratory     

Urban Svensson   《Journal of Hydrology》2001,250(1-4):187-205

A method to represent fracture networks in a continuum model is evaluated by an application to the Äspö Hard Rock Laboratory (HRL). The basic approach of the method is to first generate a fracture network, based on data from field measurements and then represent the network as grid cell conductivities, using a staggered grid arrangement. It is argued that the resulting conductivity fields capture the correlation and anisotropy structures, as well as the mean conductivity, of the rock in a realistic way. The main objective is to evaluate if the suggested method can be used in an application to a real site. The objective is formulated in three questions: ‘Can the method utilize available field data?’, ‘Can the generated fields be calibrated and conditioned?’ and ‘Are realistic distributions of pressure, flow and density obtained?’. From the application to the Äspö HRL, it is concluded that the hydraulic conductivity fields, generated by the suggested method, can utilize field data and be calibrated. It is also demonstrated that realistic distributions of pressure, flow and density can be simulated.  相似文献   

Photogrammetric Digitising Systems     

F. Urban 《The Photogrammetric Record》1981,10(58):510-510

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Erwiderung zur Diskussion Pavillon     

H. Urban 《Mineralium Deposita》1969,4(4):412-414

Ohne Zusammenfassung  相似文献   

Drought 2002 in Colorado: An Unprecedented Drought or a Routine Drought?   总被引：1，自引：0，他引：1  

Roger A. Pielke Sr.  Nolan Doesken  Odilia Bliss  Tara Green  Clara Chaffin  Jose D. Salas  Connie A. Woodhouse  Jeffrey J. Lukas  Klaus Wolter 《Pure and Applied Geophysics》2005,162(8-9):1455-1479

The 2002 drought in Colorado was reported by the media and by public figures, and even by a national drought-monitoring agency, as an exceptionally severe drought. In this paper we examine evidence for this claim. Our study shows that, while the impacts of water shortages were exceptional everywhere, the observed precipitation deficit was less than extreme over a good fraction of the state. A likely explanation of this discrepancy is the imbalance between water supply and water demand over time. For a given level of water supply, water shortages become intensified as water demands increase over time. The sobering conclusion is that Colorado is more vulnerable to drought today than under similar precipitation deficits in the past.  相似文献   

Note on dispersion in an ocean surface Ekman layer due to variable wind forcing     

Dr. Lars Rahm  Dr. Urban Svensson 《Ocean Dynamics》1993,45(1):43-54

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The sensitivity of some high-latitude boreal forests to climatic parameters   总被引：1，自引：0，他引：1  

Gordon B. Bonan  Herman H. Shugart  Dean L. Urban 《Climatic change》1990,16(1):9-29

A gap model of environmental processes and vegetation patterns in boreal forests was used to examine the sensitivity of permafrost and permafrostfree forests in interior Alaska to air temperature and precipitation changes. These analyses indicated that in the uplands of interior Alaska, the effect of climatic warming on the ecology of boreal forests may not be so much a direct response to increased air temperature as it may be a response to the increased potential evapotranspiration demands that will accompany climatic warmings. On poorlydrained north slopes with permafrost, the drier forest floor reduced the flux of heat into the soil profile. This was offset by increased fire severity, which by removing greater amounts of the forest floor increased the depth of soil thawing and converted the cold black spruce forests to warmer mixed hardwood-spruce forests. On well-drained south slopes, the increased potential water loss reduced available soil moisture, converting these mesic sites to dry aspen forests, or if too dry to steppe-like vegetation. Increases in precipitation offset the effects of increased potential evapotranspiration demands and mitigated these forest changes.  相似文献