【作者】 魏泽勋；

【导师】 方国洪；

【作者基本信息】 中国科学院研究生院（海洋研究所） ， 物理海洋学， 2004， 博士

【摘要】 基于GFDL的MOM2建立了一个全球变网格大洋环流数值模式来研究中国近海环流及其季节变化。模式在南海和渤、黄、东海以及日本海为高分辨率（1/6(），在全球其它区域为粗分辨率（3(）。利用模式结果计算了通过南海和东海开边界的体积、热、盐输运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一致性。结果显示，通过南海加入印尼贯穿流的体积、热、盐输运值为5.3Sv, 0.57PW和184Ggs-1，约占印尼贯穿流的1/4，表明南海是太平洋到印度洋贯穿流的重要通道之一。东海的黑潮输运值各为25.6Sv, 2.32PW和894Ggs-1，其中不到1/4的流量通过西表岛与冲绳岛之间的水道。热平衡计算表明，南海从太阳和大气获得净热通量，其值为0.08PW；而大气则从渤黄东海获得净热通量，其值为0.05PW。利用模式模拟结果和海平面气压分布获得了渤、黄、东、南海平均海面高度（海面地形）分布。结果表明，我国1985国家高程基准在全球平均海面之上24.7cm, 中国沿岸海面南高北低。与由大地水准测量得出的沿岸28个验潮站平均海面高度相比较，标准偏差为4.8cm，拟合系数达95.3%，通过线性回归订正，标准偏差可减至4.5cm, 表明模式结果已达到实际应用要求的准确度。依据模式结果给出了我国近海1/6(分辨率的平均海面高度值，由此并可将大陆与岛屿高程相联系，给出台湾、东沙、西沙和南沙的平均海面高度。给出模拟所得南海月平均以及年平均的海面高度和流函数分布以及等密面环流。与TOPEX/POSEIDON资料比较表明，所得海面高度距平与观测十分一致。基于这些结果，讨论了南海的环流结构。结果表明：对于表层海水来说，黑潮在冬、春和秋季均通过吕宋海峡入侵南海，夏季则表层没有入侵。但对于整海水层而言，全年均有海水从太平洋通过吕宋海峡进入南海。这一差异表明，在夏季，<WP=4>太平洋的海水是在次表层和中层入侵南海的。南海北部陆坡附近全年受气旋式环流控制。夏季的南海南部反气旋流圈、越南东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。南海海面高度和海面高度距平之间的差异明显。表明，在利用卫星高度计资料研究南海的上层环流时，长期平均海面高度的空间分布有重要意义。由等密面环流结果可以看出，次表层和中层环流具有明显的季节变化。全年均有次表层水通过吕宋海峡进入南海，并且冬季强夏季弱。中层环流最显著的特征就是与上层环流结构明显不同并几乎相反。夏季吕宋海峡中层水为西向运动，也即流入南海。深层环流较弱，季节变化不如次表层和中层明显，冬季和秋季流速大，其中又以冬季为最强；夏季和春季流速小，春季最小。研究了东中国海环流。黑潮得到较好的再现。黑潮在台湾以东海域的入流，夏季最强，冬季最弱；在吐噶喇海峡的出流则是夏季最强，秋季最弱。太平洋的海水通过西表岛-冲绳和冲绳-奄美大岛之间与东海黑潮有交换。通过西表岛-冲绳为入流。冲绳-奄美大岛之间的入流，一般发生在表层，冬、秋季强且明显，春、夏季甚至为出流（流出东海）；从26.5m层开始四季基本均为流出东海。黑潮深层存在南向逆流。台湾-对马-津轻暖流系统得到良好模拟。台湾暖流的水主要由台湾海峡和黑潮入侵水共同贡献，各个季节各有差异。但下层水则不管哪个季节，主要都来自台湾东北方向黑潮的次表层水。对马暖流的三个来源，黑潮分支一直是主要的来源。台湾暖流的贡献则冬、秋季较弱，且主要在次表层以下有贡献；夏季最强。济州岛西北面黄海水的贡献在也是冬、秋季较弱，春、夏季较强。冬季的黄、渤海环流系统得到很好再现，但夏季黄海环流模拟结果与实际差距较大。说明，如何利用MOM模式模拟黄东海夏季环流还需作进一步的探索。更多还原

【Abstract】 A variable-grid global ocean circulation model whose horizontal resolution is fine (1/6() in the South China Sea (SCS), East China Seas and Japan/East Sea, and coarse (3() in the rest part of the world ocean, was established based on GFDL’s MOM2 to study the ocean circulation of the China adjacent sea and its seasonal variation.Base on the model results, the monthly and annual mean freshwater, heat and salt transports through the open boundaries of the South and East China Seas are reported. The model results are in fairly good agreement with the existing estimates based on measurements. The computation shows that the flows passing through the South China Sea contribute volume, heat and salt transports of 5.3 Sv, 0.57 PW and 184Ggs-1, respectively (about 1/4), to the Indonesian Throughflow, indicating that the South China Sea is an important pathway of the Pacific to Indian Ocean throughflow. The volume, heat and salt transports of the Kuroshio in the East China Sea are 25.6Sv, 2.32 PW and 894Ggs-1, respectively. Less than 1/4 of those transports pass through the passage between Iriomote and Okinawa. The calculation of heat balance indicates that the South China Sea absorbs net heat flux from the sun and atmosphere with a rate of 0.08 PW, while the atmosphere gains net heat flux from the Baohai, Yellow and East China Seas with a rate of 0.05 PW. <WP=6>The mean sea surface heights (sea surface dynamic topography) of the South China, East China, Yellow and Bohai Seas are derived from the model results and surface air pressure. The result shows that the China 1985 National Altitude Datum is 24.7cm above the mean sea surface height of the world ocean. The mean sea surface in the coastal ocean adjacent to China is higher in the south than in the north. Comparison of the model results with the geodetic leveling measurements at 28 coastal tidal stations shows a standard deviation of 4.8cm and a fitting coefficient of 95.3%. After correction through linear regression, the standard deviation is reduced to 4.5cm. This indicates that the accuracy of model results is sufficient for practical application. Based on the model results, the mean sea surface heights for the study area with a resolution of 1/6 degree are given. This result also links the mean sea levels at islands with those on the mainland coast and gives the mean sea surface heights at tidal stations in Taiwan, Dongsha, Xisha and Nansha relative to the China 1985 National Altitude Datum.The model-produced monthly and annual mean transport stream functions and sea surface heights(SSH) and their anomalies，and isopycnal-surface circulation of the SCS are reported. Comparison to the TOPEX/Poseidon data shows that the model-produced monthly sea surface height anomalies (SSHA) are in good agreement with altimeter measurements. Based on the results, the circulation of the SCS is discussed. In the surface layer, the western Philippine Sea water intrudes the SCS through the Luzon Strait in autumn, winter and spring, but not in summer. However, as far as the whole water column is concerned, the water intrudes into the SCS through the Luzon Strait all the year round. This indicates that, in summer the water still intrudes into the SCS in the subsurface and intermediate layers. The area near the northern continental slope of the SCS is dominated by a cyclonic circulation all the year round. The SCS Southern Anticyclonic Gyre, SE Vietnam Off-Shore Current in summertime and SCS Southern Cyclonic Gyre in wintertime are reproduced reasonably well. The difference between the <WP=7>monthly averaged SSH and SSHA is significant, indicating the importance of the mean SSH in the SCS circulation. Based on the model-produced isopycnal-surface circulation, subsurface and intermediate circulations have remarkable seasonal variations. Subsurface water intrudes the SCS through Luzon Strait all the year round, with the strongest intrusion in winter and the weakest in summer. Intermediate circulation patterns significantly differ from the upper layer circulation. In summer, intermediate更多还原