Numerical Study of the Upper-Layer Circulation in the South China Sea   总被引：7，自引：0，他引：7  

Ching-Sheng Chern  Joe Wang 《Journal of Oceanography》2003,59(1):11-24

Upper-layer circulation in the South China Sea has been investigated using a three-dimensional primitive equation eddy-resolving model. The model domain covers the region from 99° to 122°E and from 3° to 23°N. The model is forced by the monthly averaged European Centre for Medium-Range Weather Forecasts (ECMWF) model winds and the climatological monthly sea surface temperature data from National Oceanographic Data Center (NODC). Inflow and outflow through the Taiwan Strait and the Sunda shelf are prescribed monthly from the Wyrtki estimates. Inflow of the Kuroshio branch current in the Luzon Strait is assumed to have a constant volume transport of 12 Sv (1 Sv = 10⁶ m³/s), and the outflow from the open boundary to the east of Taiwan is adjusted to ensure the net volume transport through all open boundaries is zero at any instant. The model reveals that a cyclonic circulation exists all year round in the northern South China Sea. During the winter time this cyclonic eddy is located off the northwest of Luzon, coinciding with the region of positive wind stress curl in this season. This cyclonic eddy moves northward in spring due to the weakening of the northeast winds. The cyclonic circulation becomes weak and stays in the continental slope region in the northern South China Sea in the summer period. The southwest wind can raise the water level along the west coast of Luzon, but there is no anticyclonic circulation in the northern South China Sea. After the onset of the northeast monsoon winds in fall, the cyclonic eddy moves back to the region off the west coast of Luzon. In the southern South China Sea and off the Vietnam coast, the model predicts a similar flow structure as in the previous related studies. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Long-term hydrographic variation in the Skagerrak based on the section Torungen-Hirtshals     

Danielssen  Didrik S.; Svendsen  Einar; Ostrowski  Marek 《ICES Journal of Marine Science》1996,53(6):917-925

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复合酶制剂对中国对虾消化率的影响   总被引：3，自引：0，他引：3  

仲军  王键鹏 《海洋科学》1995,19(1):57-59

添加复合酶制剂，可以提高对虾内源酶的活性，增强肝胰脏的消化作用。 对虾饲料中添加１％。复合酶制剂可使对虾总消化率和蛋白质消化率分别提高 ４．８１％和２．４６％。  相似文献   

等密度面P矢量方法在南海环流诊断研究中的应用   总被引：1，自引：0，他引：1  

王桂华  许建平 《海洋学报》2002,24(1):124-128

海流的直接测量困难而又昂贵,而采用一些数学模式间接获取流场信息也有其局限性,比如初始场、边界条件和黏性参数的确定存在较大的人为性和不确定性等问题.然而,随着海上现场观测资料的增多,近年来利用温盐资料诊断环流的研究工作也越来越多,例如采用β螺旋方法[1]、P矢量方法[2]和改进逆模式方法[3]等等;这些诊断研究成果,在一定程度上弥补了海洋环流研究中,由于海流观测资料不足而带来的缺陷.在众多诊断环流计算方法中,近年来用得较多的是P矢量方法[2,4,5],1).  相似文献   

最近6.5～2.2 Ma黄土高原粉尘通量变化及其指示的东亚冬季风演化和亚洲干旱化   总被引：13，自引：0，他引：13  

曹军骥  张小曳  安芷生  郑洪波 《海洋地质与第四纪地质》2003,23(3):97-101

黄土高原红粘土沉积与北太平洋885/886孔深海沉积记录的亚洲粉尘沉积通量对比显示,海陆风尘记录万年尺度的变化趋势一致,指示了6．5Ma以来亚洲内陆干旱化和冬季风环流变化的历史：6．5MaRP粉尘源区出现一定程度的干旱化,粉尘通量增加,为红粘土的形成提供了物质基础;5．2～3．6MaBP源区气候较为湿润,冬季风环流偏弱,导致粉尘通量大幅下降;3．6～2．6MaBP。由于青藏高原加速隆升,导致源区气候迅速干旱,冬季风环流发展,粉尘通量急剧增加。但海陆粉尘通量变化也存在差异,显示出区域及半球或全球尺度上粉尘输送方式的不同。  相似文献   

Hydrography of the East Shetland Basin in relation to decadal North Sea variability   总被引：2，自引：0，他引：2  

Turrell  W. R.; Slesser  G.; Payne  R.; Adams  R. D.; Gillibrand  P. A. 《ICES Journal of Marine Science》1996,53(6):899-916

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Study on short-range numerical forecasting of ocean current in the East China Sea Ⅱ. Three-dimensional diagnostic model and its application in the Bohai Sea     

Zhao Jinping  Shi Maochong 《海洋学报(英文版)》1994,13(2):173-188

Ｓｔｕｄｙｏｎｓｈｏｒｔ－ｒａｎｇｅｎｕｍｅｒｉｃａｌｆｏｒｅｃａｓｔｉｎｇｏｆｏｃｅａｎｃｕｒｒｅｎｔｉｎｔｈｅＥａｓｔＣｈｉｎａＳｅａ—ＩＩ．Ｔｈｒｅｅ－ｄｉｍｅｎｓｉｏｎａｌｄｉａｇｎｏｓｔｉｃｍｏｄｅｌａｎｄｉｔｓａｐｐｌｉｃａｔｉｏｎｉｎｔ...  相似文献   

Path Transition of the Kuroshio Due to Mesoscale Eddies: A Two-Layer, Wind-Driven Experiment   总被引：1，自引：0，他引：1  

Kazunori Akitomo  Masao Kurogi 《Journal of Oceanography》2001,57(6):735-741

We have executed numerical experiments using a two-layer, wind-driven ocean model with simplified coastal geometry and bottom topography to investigate the possibility of the Kuroshio path transition due to mesoscale eddies. A straight path easily changes into a meandering path due to the eddy action. For this transition, an anticyclonic eddy is preferable to a cyclonic one when imposed in the beginning region of the Kuroshio (east of Taiwan). When imposed southeast of Kyushu, on the other hand, a cyclonic eddy is more effective than an anticyclonic one. The reverse transition, from a meandering to a straight path, did not occur at all in this experiment. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Numerical Modeling of Suspended Sediment Transport in the Gulf of Kachchh Including Kandla Creek, West Coast of India     

P. C. Sinha  G. K. Jena  A. D. Rao  Indu Jain 《Marine Geodesy》2006,29(1):49-63

A depth-averaged numerical model has been developed to study tidal circulation and suspended sediment transport in the Gulf of Kachchh including Kandla creek, west coast of India. The resolution of the model is taken as 750 m × 750 m, which is found to be adequate for the gulf region. However, this resolution could not produce the realistic circulation pattern and suspended sediment concentration in the Kandla creek region. There is a major seaport at Kandla which serves as the sea gate to northwest India. Therefore, a 2-D fine resolution (75 m × 75 m) model for Kandla creek has been developed and coupled with the coarser gulf model to compute the flow features in the creek region. The model dynamics and basic formulation remain the same for both the gulf model and the creek model. The models are barotropic, based on shallow water equations, and neglect horizontal diffusion and wind stress terms in the momentum equations. The models are fully nonlinear and use a semiexplicit finite difference scheme to solve mass, momentum, and advection-diffusion equations in a horizontal plane. The tide in the gulf is represented in the model by the semidiurnal M₂ constituent mainly. In this study, no fresh water discharge conditions have been considered so the results are appropriate for the dry season. Numerical experiments are carried out to study the circulation and suspended sediment concentrations in the gulf and the creek regions. The computed results are validated with the available observations.  相似文献   

Combined tidal velocity and duration asymmetries as a determinant of water transport and residual flow in Paranaguá Bay estuary     

A. Mantovanelli  E. Marone  E. T. da Silva  L. F. Lautert  M. S. Klingenfuss  V. P. Prata  Jr.  M. A. Noernberg  B. A. Knoppers  R. J. Angulo 《Estuarine, Coastal and Shelf Science》2004,59(4):523-537

Net transports of water, salt and suspended particulate matter (SPM) for a cross-section in front of the Paranaguá Harbour (Paranaguá Bay, Brazil) are presented for eight distinct tidal cycles. Data include measurements over single spring and neap tidal cycles, during both wet and dry seasons. The main drive forces of circulation and SPM dynamics are identified. Advective transport dominated under moderate to high vertical salinity stratification and weak currents, while mixing processes dominated under well-mixed conditions generated by high currents and low freshwater input. Under partially mixed conditions, both advective and mixing processes were important. The tide-induced residual circulation dictated the magnitude and direction of residual currents and net transports of water and salt, but not of SPM transport. The SPM dynamics was intrinsically related to cyclical processes of erosion, resuspension and deposition driven by tidal currents. The turbulent mixing intensity conditioned the vertical mixing of SPM. Resuspension and vertical mixing were conspicuous in spring cycles, while the horizontal advection preponderated in the neaps. Lags between maximum currents and SPM peak concentrations occurred, with more pronounced hysteresis during ebb periods.  相似文献