南海北部环流观测研究

发布时间：2018-05-23 11:42

本文选题：南海 + 潮流和余流　；参考：《大连海洋大学》2014年硕士论文

【摘要】：本文基于南海北部走航ADCP(Acoustic Doppler Current Profile)观测资料，重点对琼州海峡的潮余流的分布特征和余流形成的动力机制，以及南海西边界流、暖流和中尺度涡的结构特征和水团属性进行研究和探讨。 2013年春季，为了研究琼州海峡的潮流共进行了33个断面的走航ADCP观测，并第一次使用改进潮汐调和分析法估算横穿海峡方向断面的潮流和余流分布。针对本研究，通过模拟实验证实改进潮汐调和分析法的可信性，其可以很好控制解中误差的大小和偏差范围。潮流椭圆主轴的方向均平行于海峡的走向，且全日潮在5个分潮（O1，K1，M2，S2和MSF）中起主导作用， O1，K1，，M2，S2和MSF分潮振幅的断面平均值比率为1.00:0.74:0.34:0.51:0.52。沿整个断面的余流均为西向，通过断面余流流速平均值和流量分别为19.3±2.4cm s-1和-0.182±0.0220Sv (Sv=106m3s-1)。动力分析表明，潮流活动比平均流场以及涡的活动更加起主导作用，且潮流的“调整”过程和海峡东西两入口的水位差是琼州海峡西向余流的主要驱动力。南海北部海流观测研究结果表明，陆架上方的表层西边界流东北和西南季风下的最大流速（流量）范围分别为26.9-67.0cm s-（10.74-9.70Sv）和20.3-61.0cm s-（10.45-13.29Sv），平均流幅和厚度分别为140km和210m。陆坡附近的南海暖流呈带状结构，东北和西南季风下最大流速（流量）范围分别为6.1-29.0cm s-1（0.14-2.44Sv）和12.3-31.2cms-1（1.10-5.68Sv），平均流幅和厚度分别为45km和700m。南海暖流大致沿着500-1000m等深线流向东北，但流动过程中有时会在114°E附近出现向南偏转的迹象。东北和西南季风环境下均抓拍到西边界流和中尺度涡相互扰动的过程，并获得完整的垂向流速结构。东北季风下的反气旋涡半径约180km，垂向深度超过800m，而西南季风下气旋涡的半径约135km，垂向深度约780m，强度略小于东北季风下的涡旋。东北季风下还抓拍到同一断面短时间内暖流和西边界流的结构变化过程。在越南半岛东部，15°N，110°E附近成功观测到有暖流通过,此位置是迄今为止所有报道中的最西侧。通过本文的研究可以对琼州海峡的潮余流以及南海北部的暖流、西边界流和中尺度涡取得有价值的认识。
[Abstract]:Based on the ADCP(Acoustic Doppler Current Profile) observations of the northern South China Sea, this paper focuses on the distribution characteristics of the tidal residual currents in the Qiongzhou Strait and the dynamic mechanism of the formation of the residual currents, as well as the western boundary currents in the South China Sea. The structure characteristics and water mass properties of warm current and mesoscale vortex are studied and discussed. In spring 2013, a total of 33 cross-section ADCP observations were carried out to study the tidal current in Qiongzhou Strait, and the improved tidal harmonic analysis method was used for the first time to estimate the distribution of tidal currents and residual currents across the channel. In this study, the credibility of the improved tidal harmonic analysis method is proved by simulation experiments, which can well control the magnitude of the error and the range of deviation in the solution. The direction of the main axis of the tidal current ellipse is parallel to the trend of the Strait, and the diurnal tide plays a leading role in the five tidal components: O1K1K1M2O2 and MSF). The cross section average ratio of the O1K1M2OS2 and MSF tidal amplitude is 1.00: 0.74: 0.34: 0.51V0.52. The residual flow along the whole section is westward, and the mean velocity and flow rate of the residual flow through the section are 19.3 卤2.4cm s-1 and -0.182 卤0.0220Sv respectively. The dynamic analysis shows that the tidal current plays a more dominant role than the average flow field and the vortex activity, and the "adjustment" process of the tidal current and the water level difference between the east and west entrance of the strait are the main driving forces of the westward residual current in the Qiongzhou Strait. The results of current observation in the northern South China Sea indicate that the maximum velocity (discharge) ranges of the surface west boundary current under the northeast and southwest monsoon above the continental shelf are 26.9-67.0cm s -N 10.74-9.70 Sv) and 20.3-61.0cm s -N 10.45-13.29 Sv, respectively, and the average current amplitude and thickness are 140km and 210 m, respectively. The warm currents in the South China Sea near the continental slope have a zonal structure. The maximum velocity (discharge) ranges from 6.1-29.0cm s-1 ~ 0.14-2.44 Sv under the northeast and southwest monsoon, respectively, and 12.3-31.2cms-1 ~ (-1) ~ 1.10-5.68 Sv ~ (-1). The average flow amplitude and thickness are 45km and 700m respectively. The warm current in the South China Sea flows roughly along the 500-1000m isobath to the northeast, but sometimes there are signs of a southward deflection near 114 掳E. The process of disturbance between the western boundary flow and mesoscale vortex was captured in the northeast and southwest monsoon environments, and a complete vertical velocity structure was obtained. The reverse vortex radius is about 180 km and the vertical depth is more than 800 m under the northeast monsoon, while the radius of the vortex is about 135 km and the vertical depth is about 780 m under the southwest monsoon, which is slightly less than that of the vortex under the northeast monsoon. The structural changes of the warm current and the western boundary current in the same section were also captured under the northeast monsoon. A warm current was observed in the eastern part of the Vietnamese Peninsula near 15 掳Nu 110 掳E. this position is the westernmost of all reports so far. Through the research in this paper, we can get a valuable understanding of the tidal residual current in Qiongzhou Strait and the warm current, western boundary current and mesoscale vortex in the northern part of the South China Sea.
【学位授予单位】：大连海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P714.1

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