首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   151篇
  国内免费   16篇
  完全免费   22篇
  海洋学   189篇
  2018年   4篇
  2017年   13篇
  2016年   10篇
  2015年   9篇
  2014年   5篇
  2013年   5篇
  2012年   9篇
  2011年   12篇
  2010年   16篇
  2009年   16篇
  2008年   19篇
  2007年   19篇
  2006年   16篇
  2005年   14篇
  2004年   2篇
  2003年   3篇
  2002年   3篇
  2001年   2篇
  1999年   1篇
  1998年   2篇
  1997年   2篇
  1994年   2篇
  1993年   1篇
  1992年   3篇
  1991年   1篇
排序方式: 共有189条查询结果,搜索用时 46 毫秒
1.
2.
对黄、东海水母暴发机理的新认知   总被引:4,自引:4,他引:2  
孙松 《海洋与湖沼》2012,43(3):406-410
基于大量实验结果和大规模海上考察和综合分析,从基础生物学和生态学的角度,对中国近海水母暴发的机理提出一种新的理论模式:水母生活史中的大部分时间以水螅体的形式生活在海底;水母种群的暴发是水螅体对环境变异的一种应激反应,是为了逃避动荡环境、扩大分布范围、寻求新的生存空间,为种群繁衍需求更多的机会的一种生存策略。导致水母种群暴发的关键过程是海洋底层温度的变动和饵料数量的变化,全球气候变化和富营养化是中国近海水母暴发的最重要诱发因素。水母暴发是全球变化下海洋生态系统演变的一种综合体现。  相似文献
3.
渤、黄海冬季海冰对大气环流及气候变化的响应   总被引:3,自引:3,他引:0  
受全球气候变暖影响,渤、黄海冬季气候呈明显的变暖趋势。在1951-2010年共60年中,后30年较前30年,气温升高了1.6℃,升幅异常显著。与此相对应,渤、黄海冬季海冰的冰级下降了0.6级。渤、黄海冰情持续偏轻与全球气候变暖趋势相当一致。冬季渤、黄海气温异常是对全球大气环流变化的响应,直接受同期东亚大气环流制约。研究表明,渤海海冰和大气环流的关系是清楚的,这对预测渤、黄海海冰具有重要意义。  相似文献
4.
福建沿海全新世高温期的气候与海面变化   总被引:3,自引:3,他引:1  
王绍鸿  吴学忠 《台湾海峡》1992,11(4):345-352
本文综合分析了福建沿海全新世高温期的孢粉资料和海平面变化资料,建立了气温和海平面变化曲线.结果表明,8ka,B.P.前为气温和海平面上升期,8ka,B.P.以来为高温期和高海平面期,海平面升降与气温升降几乎同步.  相似文献
5.
6.
7.
The regime shift of the 1920s and 1930s in the North Atlantic   总被引:3,自引:3,他引:6  
During the 1920s and 1930s, there was a dramatic warming of the northern North Atlantic Ocean. Warmer-than-normal sea temperatures, reduced sea ice conditions and enhanced Atlantic inflow in northern regions continued through to the 1950s and 1960s, with the timing of the decline to colder temperatures varying with location. Ecosystem changes associated with the warm period included a general northward movement of fish. Boreal species of fish such as cod, haddock and herring expanded farther north while colder-water species such as capelin and polar cod retreated northward. The maximum recorded movement involved cod, which spread approximately 1200 km northward along West Greenland. Migration patterns of “warmer water” species also changed with earlier arrivals and later departures. New spawning sites were observed farther north for several species or stocks while for others the relative contribution from northern spawning sites increased. Some southern species of fish that were unknown in northern areas prior to the warming event became occasional, and in some cases, frequent visitors. Higher recruitment and growth led to increased biomass of important commercial species such as cod and herring in many regions of the northern North Atlantic. Benthos associated with Atlantic waters spread northward off Western Svalbard and eastward into the eastern Barents Sea. Based on increased phytoplankton and zooplankton production in several areas, it is argued that bottom-up processes were the primary cause of these changes. The warming in the 1920s and 1930s is considered to constitute the most significant regime shift experienced in the North Atlantic in the 20th century.  相似文献
8.
地球系统模式FIO-ESM对北极海冰的模拟和预估   总被引:2,自引:2,他引:0  
评估了地球系统模式FIO-ESM(First Institute of Oceanography-Earth System Model)基于CMIP5(Coupled Model Intercomparison Project Phase 5)的历史实验对北极海冰的模拟能力,分析了该模式基于CMIP5未来情景实验在不同典型浓度路径(RCPs,Representative Concentration Pathways)下对北极海冰的预估情况。通过与卫星观测的海冰覆盖范围资料相比,该模式能够很好地模拟出多年平均海冰覆盖范围的季节变化特征,模拟的气候态月平均海冰覆盖范围均在卫星观测值±15%范围以内。FIO-ESM能够较好地模拟1979-2005年期间北极海冰的衰减趋势,模拟衰减速度为每年减少2.24×104 km2,但仍小于观测衰减速度(每年减少4.72×104 km2)。特别值得注意的是:不同于其他模式所预估的海冰一直衰减,FIO-ESM对21世纪北极海冰预估在不同情景下呈现不同的变化趋势,在RCP2.6和RCP4.5情景下,北极海冰总体呈增加趋势,在RCP6情景下,北极海冰基本维持不变,而在RCP8.5情景下,北极海冰呈现继续衰减趋势。  相似文献
9.
Between 2003 and 2006, a severe drought occurred throughout the Mondego River catchment's area, inducing lower freshwater flows into the estuary. As a consequence, both 2004 and 2005 were considered as extreme drought events. From June 2003 to June 2006, the fish assemblage of the Mondego Estuary was sampled monthly in five stations during the night, using a 2 m beam trawl. Fish abundance was standardized as the number of individuals per 1000 m2 per season and the assemblage was analyzed based on ecological guilds: estuarine residents, marine juveniles, marine adventitious, freshwater, catadromous and marine species that use the estuary as a nursery area. A total of 42 species belonging to 23 families were identified, with estuarine residents and nursery species dominating the fish community. Variations in the fish community were assessed using non-metric MDS, being defined as three distinct periods: summer and autumn 2003, 2004/2005 and winter and summer 2006. The main drought-induced effects detected were the depletion of freshwater species and an increase in marine adventitious in 2004/2005, due to an extended intrusion of seawater inside the estuary and a significant reduction in abundance during the driest period of estuarine resident species. Nevertheless, from the management point of view, it could be stated that although some variations occurred due to environmental stress, the main core of the Mondego Estuary fish community remained relatively unchanged.  相似文献
10.
The marine ecosystem located off the coast of central and northern Peru has stood as the “world’s champion” producer, by far, of exploitable fish biomass, generally yielding more than 20 times the tonnage of fishery landings produced by other comparable regional large marine ecosystems of the world’s oceans that operate under similar dynamic contexts and are characterized by comparable, or even greater, basic primary production. Two potentially contributing aspects are discussed from a framework of interregional comparative pattern recognition: (1) the advantageous low-latitude situation that combines strong upwelling-based nutrient enrichment with low wind-induced turbulence generation and relatively extended mean “residence times” within the favorable upwelling-conditioned near-coastal habitat and (2) the cyclic “re-setting” of the system by ENSO perturbations that may tend to interrupt malignant growth of adverse self-amplifying feedback loops within the nonlinear biological dynamics of the ecosystem.There is a developing scientific consensus that one of the more probable consequences of impending global climate changes will be a general slowing of the equatorial Pacific Walker Circulation and a consequent weakening of the Pacific trade wind system. Since the upwelling-favorable winds off Peru tend to flow directly into the Pacific southeast trade winds, a question arises as to the likely effect on the upwelling-producing winds that power the productivity of the regional coastal ecosystems of the Peru–Humboldt Current zone. It is argued that the effects will in fact be decoupled to the extent that upwelling-favorable winds will actually tend to increase off Peru. Data demonstrative of this decoupling are presented. A tendency for less intense El Niño episodes in the future is also suggested. These conclusions provide a framework for posing certain imponderables as to the future character of the Peruvian marine ecosystem and of the fisheries it supports.  相似文献
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号