Triple diagram method for the prediction of wave height and period   总被引：1，自引：0，他引：1  

Mehmet zger  Zekai en 《Ocean Engineering》2007,34(7):1060-1068

Many formulations have been developed so far to predict the wave height and period from fetch length and wind blowing duration for a constant wind speed. This study aimed to predict wave parameters from fetch length and meteorological factors by using triple diagram methodology based on Kriging principles. Proposed model results were compared with Joint North Sea Wave Project (JONSWAP) model which is used so commonly in the ocean and coastal engineering studies. For the implementation of the methodology hourly wave and wind data were obtained from a buoy located in Lake Ontario. Numerical and graphical comparisons demonstrated that the proposed method outperforms the classical formulation.  相似文献   

东亚冬夏季风对热带印度洋秋季海温异常的响应   总被引：5，自引：0，他引：5  

李东辉  谭言科  张瑰  叶志敏 《热带海洋学报》2006,25(4):6-13

利用多年的Reynolds月平均海表温度资料和NCEP/NCAR全球大气再分析资料,分析了热带印度洋秋季海表温度距平(SSTA)与后期东亚冬夏季风强度变化的关系。结果表明,热带印度洋秋季SSTA的主要模态是全区一致(USB)型和偶极子(IOD)型,USB型模态主要代表热带印度洋秋季SSTA的长期变化趋势,而IOD型模态主要反映热带印度洋秋季SSTA的年际变化。热带印度洋秋季海温气候变率中既存在着明显的ENSO信号,也有独立于ENSO的变率特征,独立于ENSO的热带印度洋秋季SSTA变化的主要模态仍是USB型和IOD型。前期秋季USB模态与东亚冬季风及东亚副热带夏季风之间为负相关关系;与前期正(负)IOD模态相对应,南海夏季风强度偏弱(强),而东亚副热带夏季风强度偏强(弱)。USB型和IOD型模态对后期东亚冬、夏季风强度变化的影响是独立于ENSO的,但ENSO起到了调节二者相关显著程度的作用。  相似文献   

北极海冰减少的气候效应研究   总被引：2，自引：0，他引：2  

魏立新  张海影 《海洋预报》2005,22(Z1):56-61

本文采用了OSU两层大气环流模式对特定的北极海冰进行数值模拟,研究北极海冰减少的气候效应.试验中海温一律取为气候平均值,北极海冰作为外强迫源影响大气,大气响应完全是环流内部调整的结果.本文对北极海冰减少后的大气环流特征进行了分析,特别是与中国的气温和降水之间的关系.  相似文献   

Effects of winds,tides and storm surges on ocean surface waves in the Sea of Japan     

ZHAO Wei  TIAN Jiwei  LI Peiliang  HOU Yijun 《海洋学报(英文版)》2007,26(3):9-21

Ocean surface waves are strongly forced by high wind conditions associated with winter storms in the Sea of Japan. They are also modulated by tides and storm surges. The effects of the variability in surface wind forcing, tides and storm surges on the waves are investigated using a wave model, a high-resolution atmospheric mesoscale model and a hydrodynamic ocean circulation model. Five month-long wave model simulations are inducted to examine the sensitivity of ocean waves to various wind forcing fields, tides and storm surges during January 1997. Compared with observed mean wave parameters, results indicate that the high frequency variability in the surface wind filed has very great effect on wave simulation. Tides and storm surges have a significant impact on the waves in nearshores of the Tsushima-kaihyō, but not for other regions in the Sea of Japan. High spatial and temporal resolution and good quality surface wind products will be crucial for the prediction of surface waves in the JES and other marginal seas, especially near the coastal regions.  相似文献   

A probability distribution for depth-limited extreme wave heights in a sea state     

Fernando J. Mndez  Sonia Castanedo 《Coastal Engineering》2007,54(12):878-882

A model for the depth-limited distribution of the highest wave in a sea state is presented. The distribution for the extreme wave height is based on a probability density function (pdf) for depth-limited wave height distribution for individual waves [Méndez, F.J., Losada, I.J., Medina, R. 2004. Transformation model of wave height distribution. Coastal Eng, Vol. 50, 97:115.] and considers the correlation between consecutive waves. The model is validated using field data showing a good representation of the extreme wave heights in the surf zone. Some important statistical wave heights are parameterized obtaining useful expressions that can be used in further calculations.  相似文献   

The impact of the M₂ internal tide on data-assimilative model estimates of the surface tide     

E.D. Zaron  G.D. Egbert   《Ocean Modelling》2007,18(3-4):210-216

We use a synthetic data experiment to assess the accuracy of ocean tides estimated from satellite altimetry data, with emphasis on the impact of the phase-locked internal tide, which has a surface expression of several centimeters near its sites of genesis. Previous tidal estimates have regarded this signal as a random measurement error; however, it is deterministic and not scale-separated from the barotropic (surface) tide around complex bathymetric features. The synthetic data experiments show that the internal tide has a negligible impact on the barotropic tidal fields inferred under these circumstances, and the barotropic dissipation (a quadratic functional of the tidal fields) is in good agreement with the energetics of the three-dimensional regional primitive equations model which is the source of the synthetic data.  相似文献   

利用卫星测高技术监测厄尔尼诺和拉尼娜现象   总被引：2，自引：0，他引：2  

赵小阳  李建成  王正涛  金涛勇 《海洋测绘》2007,27(1):41-44

利用美国宇航局和法国空间局联合公布的T／P数据（1993-2000年）和Jason-1数据（2002—2006年），由共线法计算了热带太平洋地区海平面高度的变化。根据T／P和Jason-1数据计算的海面月变化异常图，分别研究了和分析了1997-1998年的厄尔尼诺和拉尼娜现象、2002-2003年厄尔尼诺现象的变化发展过程。  相似文献   

中国东海2万年来海平面变化分析   总被引：4，自引：0，他引：4  

辛立国  李广雪  李西双  马妍妍 《中国海洋大学学报(自然科学版)》2006,36(5):699-704,698

拟通过中国东海相对海平面与全球海平面对比分析，来获得东海构造沉降数据。但在对比分析的过程中发现，断裂作用对中国东海150m以深海域相对海平面的变化有重要影响。这种作用使东海150m以深海底至少下降了30m，这是我国学者先前误认为中国东海末次冰盛期最低海面位置位于现今海面下150～160m一带的主要原因。在此基础上，进一步对水与冰川重力均衡、沉积物压实和构造沉降作用进行了探讨。结果认为重力均衡不足、沉积物压实作用微弱，构造沉降是造成东海相对海平面与全球海面之间差异的又一重要原因。同时发现东海构造沉降随水深呈规律性变化。断裂作用的表现结果所赋予的更深层次的思考与认识是，在17kaB．P．以前，中国东海水深150～160m一带是1个相对隆起带，其存在对陆架区圈闭和捕获中国大陆古水系和沉积物具有重要意义。  相似文献   

Crustal Thinning of the Northern Continental Margin of the South China Sea   总被引：2，自引：0，他引：2  

Ching-Hui Tsai  Shu-Kun Hsu  Yi-Ching Yeh  Chao-Shing Lee  Kanyuan Xia 《Marine Geophysical Researches》2004,25(1-2):63-78

Magnetic data suggest that the distribution of the oceanic crust in the northern South China Sea (SCS) may extend to about 21 °N and 118.5 °E. To examine the crustal features of the corresponding continent–ocean transition zone, we have studied the crustal structures of the northern continental margin of the SCS. We have also performed gravity modeling by using a simple four-layer crustal model to understand the geometry of the Moho surface and the crustal thicknesses beneath this transition zone. In general, we can distinguish the crustal structures of the study area into the continental crust, the thinned continental crust, and the oceanic crust. However, some volcanic intrusions or extrusions exist. Our results indicate the existence of oceanic crust in the northernmost SCS as observed by magnetic data. Accordingly, we have moved the continent–ocean boundary (COB) in the northeastern SCS from about 19 °N and 119.5 °E to 21 °N and 118.5 °E. Morphologically, the new COB is located along the base of the continental slope. The southeastward thinning of the continental crust in the study area is prominent. The average value of crustal thinning factor of the thinned continental crust zone is about 1.3–1.5. In the study region, the Moho depths generally vary from ca. 28 km to ca. 12 km and the crustal thicknesses vary from ca. 24 km to ca. 6 km; a regional maximum exists around the Dongsha Island. Our gravity modeling has shown that the oceanic crust in the northern SCS is slightly thicker than normal oceanic crust. This situation could be ascribed to the post-spreading volcanism or underplating in this region.  相似文献   

气候变化中海洋和冰冻圈的变化、影响及风险     

王慧  刘秋林  李文善  潘嵩  李琰  王爱梅  徐浩  吕江华 《海洋通报》2020,39(2):143-151

本文系统梳理了IPCC 《气候变化中的海洋和冰冻圈特别报告》(SROCC)的主要结论,并对主要观点进行了解读。报告主要关注全球变暖背景下高山、极地、海洋和沿海地区现在和未来的变化及其对人类和生态系统的影响,以及实现气候适应发展路径的方案。在全球变暖背景下,冰冻圈大面积萎缩,冰川冰盖质量损失,积雪减少,北极海冰范围和厚度减小,多年冻土升温,全球海洋持续增温,1993年以来,海洋变暖和吸热速度增加了一倍以上。同时,海洋表面酸化加剧,海洋含氧量减少。全球平均海平面呈加速上升趋势,2006—2015年全球海平面上升速率为3.6 mm/yr,是1901—1990年的2.5倍,但存在区域差异。高山、极地和海洋的生态系统的物种组成、分布和服务功能均发生变化,并对人类社会产生了显著负面影响。极端海洋气候事件发生频率增多,强度加大。1982年以来,全球范围内海洋热浪的发生频率增加了一倍,且范围更广,持续时间更长。海平面持续上升加剧了洪涝、海水入侵、海岸侵蚀等海岸带灾害,并影响沿海生态系统。海洋及冰冻圈的变化及其影响在未来一定时期仍将持续,应对这些影响而面临的挑战,应加强基于生态系统的适应和可再生能源管理,强化海岸带地区的海平面上升综合应对,打造积极有效、可持续和具有韧性的气候变化应对方案。  相似文献