东海北部的一个气旋型涡旋

东海北部是几个流系交汇的地方，东有黄海暖流向西北流人黄海，西有所谓黄海沿岸流南下，南有黑潮北上余脉；另外，在夏季，上层还有长江冲淡水的影响(见图1)。因此，这里的水文状况相当复杂，曾引起了不少中外学者的注意。井上尚文根据1969年11月在该海区投放的海底漂流器资料分析的结果表明，济州岛西南海域的底层流，在秋、冬两季为一范围相当大的反时针水平环流。胡敦欣等进一步指出，夏季在大约以31°30’N，125°30''E为中心，尺度为100-200km 的范围内存在着一个气旋型涡旋；阐明了这一涡旋形成的动力原因(黄海暖流、黄海沿岸流和黑潮北上余脉之间的相互作用)和热力学因子(黄海冷水的南伸)；对这一海区海底圆形软泥沉积的形成机制作了简要的说明，并依此推测这一涡旋的常年存在。近几年来，我们又作过多次专题性调查，取得了较好的资料。本文旨在进一步论证这一涡旋的常年存在，阐明其多年变化，探讨引起这种变化的原因，并讨论几个有关的问题。     

船上海气之间湍流通量的观测研究

用６个加速度计组阵系统来监测船体姿态和运动，校正船上观测到的风湍流资料，然后用涡动相关技术计算海气之间动量，热量和水汽通量，结果表明，本观测系统可精确地消除船体运动对风湍流的影响，并获得精确的海气湍流通量。     

渤、黄、东海海流和潮汐共同作用下的悬浮物输运、沉积及其季节变化

渤、黄、东海是一个水动力状况相当复杂的半封闭宽陆架海,本海区悬浮颗粒物含量高,季节变化明显,影响范围广,是世界上悬浮物含量最高的海域之一。对于该海域悬浮物的输运沉积过程、分布规律以及底质分布等中外学者均进行过比较深入的研究(秦蕴珊,1963;Honjo et al.,1974;Milliman et al.,1985,1986;秦蕴珊等,1987,1989;杨作升等,1992;Li et al.,1997;孙效功等,2000;雷坤等,2001)。然而,以往的研究大都基于实际海洋调查资料,由于受实测资料在时间和空间覆盖范围上的限制,很难从整体上把握渤、黄、东海陆架区悬浮物输运的时间和空间变化规律。数值模拟的方法能很好地克服上述局限,已有学者从不同角度对渤、黄、东海的某些海域的悬浮物进行了模拟研究。     

A THEORETICAL SOLUTION FOR THE THERMOHALINE CIRCULATION IN THE SOUTHERN YELLOW SEA

Application of the thermocline equations in the thermocline areas and the boundary layer and the asymptotic matching techniques in each boundary in order to satisfy the surface and bottom conditions yielded a theoretical 2- D solution of the vertical thermohaline circulation of the Southern Yellow Sea in summer when the quasi-statically varying seasonal thermocline (density layer) is the background density structure , the deviations from which cause the secondary vertical circulation . The results show that the thermocline can be considered as an internal boundary or a barrier to the vertical heat advection so that in the central areas of the Southern Yellow Sea or the center of the Yellow Sea Cold Water Mass(YCWM)> the downwelling in the upper layer and upwelling in the lower or bottom layer form a double cell vertical circulation . The solution is similar to Hu's conceptual model ( 1986) in the central areas of the YCWM and is consistent with observed temperature . salinity and dissolved oxygen distri     

A time-dependent baroclinic model on NEC bifurcation

As it is well-known, the North Equatorial Current (NEC) bifurcates into the Kuroshio flowing northward and the equatorward Mindanao Current, which is well depicted by Munk’s theory in 1950 in terms of its climatology. However, Munk’s theory is unable to tell the NEC bifurcation variability with time. In the present paper, a time-dependent baroclinic model forced by wind, in which temporal and baroclinic terms are added to Munk’s equation, is proposed to examine the seasonal variability of the NEC bifurcation latitude. An analytical solution is obtained, with which the seasonal variability can be well described: NEC bifurcation reaches its northernmost position in December and its southernmost position in June with a range of about 1° in latitude, consistent with previous results with observations. The present solution will degenerate to Munk’s one in the case of steady and barotropic state.     

Effect of low-frequency Rossby wave on thermal structure of the upper southwestern tropical Indian Ocean

We investigate the influence of low-frequency Rossby waves on the thermal structure of the upper southwestern tropical Indian Ocean (SWTIO) using Argo profiles, satellite altimetric data, sea surface temperature, wind field data and the theory of linear vertical normal mode decomposition. Our results show that the SWTIO is generally dominated by the first baroclinic mode motion. As strong downwelling Rossby waves reach the SWTIO, the contribution of the second baroclinic mode motion in this region can be increased mainly because of the reduction in the vertical stratification of the upper layer above thermocline, and the enhancement in the vertical stratification of the lower layer under thermocline also contributes to it. The vertical displacement of each isothermal is enlarged and the thermal structure of the upper level is modulated, which is indicative of strong vertical mixing. However, the cold Rossby waves increase the vertical stratification of the upper level, restricting the variability related to the second baroclinic mode. On the other hand, during decaying phase of warm Rossby waves, Ekman upwelling and advection processes associated with the surface cyclonic wind circulation can restrain the downwelling processes, carrying the relatively colder water to the near-surface, which results in an out-of-phase phenomenon between sea surface temperature anomaly (SSTA) and sea surface height anomaly (SSHA) in the SWTIO.     

历史水文观测数据反演的热带太平洋西边界流多年代变化趋势

大尺度海洋环流是海洋能量再分配的基本物理过程之一,研究西太平洋海洋环流在全球气候变暖背景下的多年代变化趋势对理解和预测未来西太平洋气候变化具有重要意义.本文利用最新发布的世界大洋数据集(WOA18)的年代平均水文观测时间序列,计算了1955～2017年间热带西太平洋北赤道流、北赤道逆流、棉兰老流、源地黑潮和新几内亚沿岸...     

137°经向断面温、盐度的年际变异

系统地分析了１３７°Ｅ断面温、盐度的多年变化,主要结果为：（１）１３７°Ｅ断面１００ｍ层温度,在低纬度海域于某些年份出现异常低温,此现象可能与厄尔尼诺事件有关;指出棉兰老冷涡的存在是造成该断面于６°～８°Ｎ附近出现低温的主要原因．（２）厄尔尼诺期间,冬季１３７°Ｅ断面上２８℃等温线所在纬度小于其多年平均值．（３）冬季１３７°Ｅ断面上次表层高盐水可划分为强型、次强型、中等型和弱型４种类型．     

热带印度洋Rossby波的基本特征

<正>海洋斜压长Rossby波在海洋动力学中占据重要地位,是物理海洋学研究的一个重要任务。它维持并影响大洋西边界流,是海盆内能量传播的主要机制,是海洋对大气驱动的主要响应现象(Pedlosky,1979;Gill,1982)。20世纪70年代以来,XBT资料的积累使人们能够从水文资料中,特别是次表层海温的变化中发现大尺度Rossby波的存在依据(White,1977;Kessler,1990),且集中在     

黄海夏季近岸海区环流的初步分析及其与风速的关系

2008年夏季,青岛近海海域浒苔大规模暴发,引起人们对黄海夏季近海环流的特别关注。该文通过分析江苏外海一个观测站点上的近26 d的夏季海流观测资料,发现这里存在一支流向比较稳定的北向流,垂向平均流速约3.4 cm/s,最大流速8 cm/s。研究表明,该北向流的变化主要受局地风场控制,南北向的流动与南北向风速的大小关系密切。