| 摘要: |
| 根据浙江中部近海2018年4月—2018年10月的近岸锚系流速观测数据和同步的风速风向数据，结合锚系点周边水域全潮大、中、小潮水文观测资料，进而分析了该海域水流的变化特征。锚系点余流主要沿着与等深线平行的方向（东北-西南向），余流散点图的主轴方向为25.5°（东北偏北向），沿着主轴方向的余流与垂直于主轴方向的余流标准差分别为0.12 m/s和0.02 m/s。余流北分量和风速北分量具有良好的相关性，两者月平均时间序列的相关系数达到了0.96，逐时整点时间序列的相关系数为0.69。锚系点余流具有13.37 d和28.49 d的周期性变化特征，该周期与大、小潮的更替周期非常接近。小潮期间，潮流的强度相对较弱，余流对风的响应较为显著，余流和风的相关性较好，两者相关系数为0.72；而在大潮期间，潮差较大且潮流流速较强，余流和风的相关性相对较差，两者相关系数为0.30。本研究，得到了锚系点及其周边水域的流速分布特征，初步获悉天文潮和风场等的非线性作用对研究区域潮流和余流的影响，可以为浙江中部沿岸海洋开发和环境保护提供动力学方面的依据。 |
| 关键词: 浙江中部近海 沿岸流 风生流 天文潮 余流周期变化 |
| DOI：10.11759/hykx20190423001 |
| 分类号:P731 |
| 基金项目:浙江省自然科学基金项目（LQ19D060007） |
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| Coastal current and its response to wind and spring—Neap cycles in the middle Zhejiang coastal area |
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HU Feng-tao, TAO Yu
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Zhejiang Ocean Surveying and Mapping Technology Co., Ltd., Hangzhou 310052, China
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| Abstract: |
| The flow characteristics of the western part of the East China Sea were examined using the velocity data obtained from a mooring site on the 15 m isobath and wind vector data, both of which were recorded over a seven-month period (April-October, 2018), and hydrological measurements from the spring, middle, and neap tides in the waters around the mooring site. Subtidal currents at the mooring site flowed mainly along the northeast-southwest direction and were parallel to the isobath; the major axis of the current variance ellipse was along the NNE direction at an angle of 25.5°; and the major and minor axes of the current variance ellipse were 0.12 and 0.02 m/s, respectively. The northerly flow and wind components were well correlated, and the correlation coefficients of their monthly means and hourly values reached 0.96 and 0.69, respectively. The subtidal flow at the mooring site varied periodically at 13.37 and 28.49 days, which were very close to the length of the spring-neap cycle. The tidal ranges of the neap tides were smaller than those of the spring tides. The subtidal flow and the winds were positively correlated, with a coefficient of 0.72. During the spring tides, the tidal ranges and currents were larger and stronger, respectively; however, a weaker relationship existed between the subtidal flow and wind, with a correlation coefficient of 0.30. In this paper, the velocity distribution characteristics of the anchoring point and its surrounding waters are determined and the influence of the nonlinear effects of astronomical tide and wind field on the tidal and residual currents is preliminarily discussed. The results can provide a dynamic basis for marine development and environmental protection in the middle Zhejiang coastal area. |
| Key words: middle Zhejiang coastal area coastal current wind-driven current astronomical tide periodic variation of residual current |
