| 摘要: |
| 采用CTD、多参数环境监测系统-YSI等仪器设备, 于2000年8月在长江口外海区对长江冲淡水结构、羽状锋等进行了现场观测。2000年8月长江冲淡水出口门后, 朝东北偏北流动, 而当年8月为长江径流量偏小的月份。通过动力分析指出了近口门段长江冲淡水分布类型与径流量的关系。长江冲淡水主流在近口门附近朝东北偏北扩展后, 在科氏力作用下朝东南扩展, 在转向区域为沿水下河谷北上的高盐台湾暖流水。高盐的台湾暖流水和长江冲淡水混合, 生成口外羽状锋, 强度大, 阻挡了长江冲淡水向东扩展, 并使冲淡水在当年径流量偏小情况下朝东北偏北运动。部分台湾暖流水在中下层能穿越长江口外而向北流动。羽状锋主要存在于长江口外122.6°E附近的15m水层之上。在浙江沿岸、长江口外水下低谷西侧、吕泗近岸存在着上升流现象。
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| 关键词: 长江冲淡水,羽状锋,上升流,台湾暖流,现场观测 |
| DOI：10.11693/hyhz200303003003 |
| 分类号: |
| 基金项目:国家重点基础研究发展规划项目(973),G1999043803号、高等学校优秀青年教师教育和科研奖励基金项目,国家自然科学基金项目,49876002号 |
附件 |
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| OBSERVATION OF THE DILUTED WATER AND PLUME FRONT OFF THE CHANGJIANG RIVER ESTUARY DURING AUGUST 2000 |
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ZHU Jian-Rong1, DING Ping-Xing1, HU Dun-Xin2
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1.State Key Laboratory of Estuarine and Coastal Research;2.Institute of Oceanology, The Chinese Academy of Sciences
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| Abstract: |
| Using CTD, Multi-paramete rEnvironmental Monitoring Systems-YSI and other instruments, observations of the diluted water and plume front off the Changjiang River estuary were undertaken during August 2000.The main axis of the Changjiang diluted water expands towards the northeast-north after it leaves the mouth (the river discharge in August 2000 is smaller than the long-term average). Based upon dynamic analysis, the relationship between the pattern of expansion of the Changjiang diluted water and river discharge is obtained. The Changjiang diluted water expands to southeastward after the main axis northeast-northward expands near the Changjiang River estuary.There exists more saline water of the Taiwan Warm Current flowing northward along the sub-aqueous river valley near the area where the Changjiang diluted water changes its direction. Mixing of the saline water of the Taiwan Warm Current and the Changjiang diluted water generates a plume front which is strong and blocks eastward expanding of the diluted water and makes it move to northeast-northward, in response to smaller river discharge in August 2000. A part of the Taiwan Warm Current can flow across the area off the Changjiang River estuary, towards the north in the middle and lower layers. The plume front is mainly located near 122.6°E, in the upper 15m layer.Upwelling is present along the Zhejiang coast, west of the submarine river valley and Lusi coast.
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| Key words: Changjiang diluted water, Plume front, Upwelling, Taiwan Warm, Current field observation |
