本文利用2009年6月至11月期间的ADCP海流资料,研究了獐子岛附近一个固定观测点处的时间平均流及潮流特征。结果表明,该海区的平均流大致沿等深线方向,从黄海流向渤海,整个观测期间纬向平均流大于经向平均流,经向1m宽度范围内的纬向净水体输运量为0.67m^3/s,而纬向1m宽度内的经向净水体输运量为0.16m^3/s;垂向上可以15m和47m为节点分为三层,15m大致为温跃层深度,而47m以下为底摩擦影响显著的范围。夏季的温盐层化结构对于余流的垂直分布存在显著影响。潮流调和分析表明,该海区的潮汐类型为正规半日潮,M2和K1分潮在整个深度范围内的平均振幅分别为27.9cm/s和9.2cm/s,半日潮流由表及底均为旋转流,而全日潮流更趋向于往复流。在垂向上,各个分潮的潮流椭圆均随深度发生小幅度的旋转,半日潮流椭圆随深度逆时针旋转,倾角变化小于30°,全日潮流椭圆随深度顺时针旋转,倾角变化小于40°。潮流在近底层受到底摩擦的影响十分显著,其中全日潮流受到底摩擦的影响较半日潮流大。本次观测是进一步研究北黄海区域潮流、近惯性流动与水体交换输运的直接参考,其结果加深了对该区域流场特性的认识和理解。
Several analysis methods are adopted in this paper to study direct continuous current measurements in the northern Yellow Sea during the year of 2009, including power spectrum analysis, harmonic analysis and Empirical Orthogonal Function(EOF) analysis. The results show that the average flow in the station area is roughly southwestern along the 50 m isobaths, and the zonal mean flow is greater than the meridional mean flow over the whole observation period, with the zonal and meridional water transport being 0.67m^3/s and 0.16m^3/s, respectively. The thermohaline stratification in summer has significant effects on the vertical distribution of residual current. The tide harmonic analysis shows that the tidal type of this area is regular semi-diurnal tide, and the average amplitudes of M2 and K1 are 27.9cm/s and 9.2cm/s, respectively. Semi-diurnal tide systems are rotary tidal current and diurnal tide systems are inclined to reciprocate. Semi-diurnal ellipses vary anticlockwise with depth increasing with inclination change less than 30°, and diurnal ellipses vary clockwise with inclination change less than 40°. Bottom friction influences dramatically, and it affects diurnal tide more than semi-diurnal tide to larger depth scope. This observation is a direct reference to the further study of tidal flow, inertial flow and water exchange in the northern Yellow Sea, and the current results deepen the understanding of current field characteristics.