【作者】 连展；

【导师】 魏泽勋；

【作者基本信息】 国家海洋局第一海洋研究所 ， 物理海洋学， 2008， 硕士

【摘要】 为了研究中国近海环流及其与外海大洋环流之间的相互作用,本文基于MITgcm建立了一个变网格全球大洋环流模式。模式在南海和渤、黄、东海及日本海为高分辨率(1/6°),在全球其他区域为低分辨率(2°)。与TOPEX/POSEIDON卫星高度计资料和黑潮的测流资料比较表明,模拟结果与观测结果符合良好。利用模拟结果计算了通过中国近海各开边界的体积、热、盐输运量的各月和全年平均值。所得结果与已有的基于观测所得的体积输运估计值有良好的一致性。东海黑潮的体积和热盐输运值分别为23.27Sv,1.96PW和805.49Gg/s。其中西表岛至冲绳水道的输运量只占总量的2.6%。结果显示南海为太平洋-印度洋贯穿流的重要通道。热平衡计算表明,大气从渤、黄、东海获得净热通量,其值为0.02PW,南海地区则是海洋从大气中吸收热量,值约为0.03PW。利用模拟结果研究了渤、黄、东海的环流结构及其季节变化。黑潮得到了较好的再现。黑潮主要通过台湾至西表岛水道进入东海,在吐噶喇海峡流出东海。其流量具有明显的季节变化,夏季最大,冬季最小。台湾-对马-津轻暖流系统得到了良好的再现。台湾暖流主要来源于台湾海峡海流和黑潮入侵,并具有季节变化。其中台湾海峡来水在其中占据了主要地位。对马暖流存在三个来源,分别为台湾暖流、济州岛西侧黄海水和黑潮。它们的贡献随季节变化各有不同。台湾暖流所占部分在冬、秋季贡献较弱,且主要集中在次表层,在夏季较强。济州岛西侧黄海水部分则在冬季最强,夏季较不明显。黄海夏季环流的模拟结果与观测有一定出入,说明如何将MITgcm模式更好的利用在黄海环流的模拟中还需进一步的探索。基于模拟结果讨论了南海的环流结构及其季节变化。结果表明:全年均有太平洋水通过吕宋海峡进入南海,夏季表层的入侵较弱。南海北部附近全年都存在气旋式流圈。夏季南海南部反气旋式流圈、越南离岸流和冬季的南海南部气旋流圈都得到了很好的再现。垂直结构上,中层环流与上层环流结构并不相同,甚至出现相反的情况。更多还原

【Abstract】 A variable-grid global ocean circulation model is established based on MITgcm to study the ocean circulation of the China adjacent seas and its seasonal variation. The horizontal resolution of the model is fine (1/6°) in the South China(SCS),East China Seas, and Japan/East Sea, and coarse(2°) in the rest part of the world ocean.The model-produced monthly mean transport stream functions and the anomalies of the sea surface heights .Comparison to the TOPEX/Poseidon data shows that the model-produced monthly sea surface height anomalies are in good agreement with altimeter measurement. This shows the correctness of the result of the model.Based on the model result, the monthly and annual mean freshwater, heat and salt transports through the open boundaries of the Bohai Sea, Yellow Sea, East and South China Seas are calculated. The model results are in fairly good agreement with the existing estimates based on measurements. The computation shows that the volume, heat and salt transports of the Kuroshio in the East China are 23.35Sv, 1.96PW and 805.49Gg/s. Only about 2.6% of those transports pass through the passage between Iriomote and Okinawa. The result indicates that the South China Sea is an important pathway of the Pacific to Indian Ocean throughflow. The calculation of heat balance indicates that the atmosphere gains net heat flux from the Baohai, Yellow and East China Seas with a rate 0.02PW while the South China Sea absorbs net heat flux from the sun and atmosphere with a rate of 0.03PW.Based on the model results, the circulation of Bohai, Yellow and East China Seas and their seasonal variation are studied. Kuroshio is reproduced reasonable well. Kuroshio mainly intrudes the East China Sea through the Taiwan-Iriomote passage and flows out through the Tokara Strait. The transports are strongest in summer and weakest in autumn. Tanwan-Tsushima Warm Current System is well reproduced. The water of Taiwan Warm Current is mainly from the Taiwan Strait and Kuroshio with significant seasonal variability, the water from Taiwan Warm Current is more important. The water of Tsushima Warm Current has three sources, their contribution is seasonal variable. The part of Taiwan Strait is weak in winter and autumn and the strongest in summer. There are some deviations between the model and the observation, it show that the model doesn’t work very well in the Yellow Sea and there are something we should improve.Based on the model results, the circulation of South China Seas and their seasonal variation are studied.It shows that the Kuroshio can enter the South China Sea all the year, which is wearker in summer. The anticyclone eddies in the south of South China Sea in summer, the Vietnamese Offshore Current and the cyclone eddies in winter are reproduced very well. The circulation in the upper layer is different from the circulation in the middle layer and the bottom layer.更多还原