浙江近海夏季流场特征分析  

Current conditions in summer in the Zhejiangoffshore

作　　者：李鹏[1] 王思荐 李延刚[1] 秦渭华[1] 

机构地区：[1]国家海洋局东海预报中心,上海200081

出　　处：《海洋学研究》2014年第3期16-25,共10页Journal of Marine Sciences

基　　金：国家海洋局东海青年海洋科学基金项目资助(201210);我国近海海洋综合调查与评价项目资助(908-01-ST05)

摘　　要：为了揭示浙江近岸流场特征及沿程变化规律,于2006年和2009年夏季在浙江岸外3个固定点利用ADCP潜标进行了多个潮周期分层海流流速、流向观测.研究结果表明：（1）浙江沿岸流在中北部海域（A和B站位）为旋转流,流向呈顺时针方向旋转,在南部（C站位）涨潮流方向基本为北向,落潮方向为东偏北向;各站位海流在垂向上流向较一致.（2）3个站位垂线平均流速相近（44.4～51.1cm/s）,但平均流速的垂向分布差异明显;各站的最大流速均大于110 cm/s,且均出现在大潮涨急时刻.（3）观测期间,A（北部）、B（中北部）和C（南部）站位平均余流的大小分别为21.9,12.3和22.3cm/s;受长江冲淡水影响,A和B站位中上层余流为西南向,从中层向底层流向呈逆时针方向偏转,下层流向呈东南向,可能为台湾暖流牵引所致,C站位余流流向在垂向较为一致,均为东北向,主要受季风影响.（4）夏季浙江沿岸流在沿浙江沿岸北上的过程中,在浙江中部（B和C站位中间）逐渐向东偏转（可能受台湾暖流的牵引）,流经海域水深变大.（5）在夏季长江径流量偏小时段,浙江中北部近岸海域也存在向南的沿岸流（同冬季）,其范围从长江口以南一直至浙江中北部.浙江近岸海流受季风、长江冲淡水和台湾暖流共同制约,但各区域的主要受控因素不同.To research the current character, variation and pattern in vertical profile, current speed and direction were observed using ADCP at 3 fixed sites along the Zhejiang offshore in summer of 2006 and 2009. The results showed that. （1） In central and north of Zhejiang offshore （A and B sites）, the current was rotating flow and it rotated in clockwise direction. In the south area（C site）, the flood tidal current was north,while it was north by east in ebb period. In vertical profile, the current direction was unanimous. （2） The vertical average speed was similar in the three observation sites （44. 4~51. 1 cm/s）, but significant difference presented in average speed of vertical profile. The biggest speeds in the three sites were all bigger than 110 cm/s, which all occurred in the flood period in spring tide. （3） During observation period, the average residual flow speed at A, B and C site was 21.9, 12.3 and 22.3 cm/s, respectively. Influenced by the Yangtze diluted water, at A and B sites the residual current directions in the upper layers were southwest. From the middle to the bottom layers the residual currents were veering in counter clockwise direction with the southeast direction in lower layers, which may be caused by the Taiwan Warm Current traction. At C site residual current flow was more consistent in vertical, which was mainly affected by the northeast monsoon. （4）In summer, along the Zhejiang offshore from south to north, the current direction turned to east gradually at central area （between B and C site）. （5）During the low water discharge of Yangtze, the south costal current existed in the central and north of Zhejiang offshore. The current adjacent to Zhejiang was controlling by monsoon, the Yangtze diluted water and the Taiwan Warm Current together, but the role of them varied significant spatially.

关 键 词：流场 夏季 沿程变化 浙江近海 

分 类 号：P731.2[天文地球—海洋科学]