南海北部陆架坡折带潮流和低频流特征分析

发布时间：2018-03-06 22:02

本文选题：南海北部　切入点：潮流　出处：《海洋与湖沼》2017年02期 　论文类型：期刊论文

【摘要】：利用旋转谱分析、调和分析和低通滤波的方法,对1987年8月至1988年1月南海北部东沙附近陆架坡折带处定点海流观测资料进行分析,研究了该区域定常余流、潮流和低频流的特征。各观测层次定常余流基本为西向流,垂向呈现较强的正压性。潮流以日分潮和半日分潮为主,呈顺时针方向旋转,全日潮流椭圆长轴普遍大于半日潮流,冬季K1分潮振幅在近底层明显增大,海流在中间层存在明显的惯性振荡。从能量角度分析,剩余流占海流总能量比例较大,定常余流能量主要存在于沿岸线方向,而垂直于岸线方向的能量主要由潮流和剩余流构成。低频流存在显著的季节变化,1988年1月呈现明显的顺时针旋转形态。冬季海表面风应力与次表层低频流有较强的相关性。结合OFES(Ocean General Circulation Model for the Earth Simulator)模拟结果,利用动量平衡分析的方法探究了动量方程中各项对低频流的贡献以及1988年1月次表层出现北向流的动力机制。冬季低频流具有较强的地转流特征,垂向分布受海水层化影响;东北风松弛和反气旋涡的联合作用是次表层出现偏北向流动的主要原因。
[Abstract]:Using the rotating spectrum analysis, harmonic analysis method and low pass filtering, from August 1987 to January 1988 in the northern South China Sea east sand near the shelf break zone at the point of current observation data analysis, to study the regional unsteady characteristic of tidal and residual current, low frequency current. The observed level of steady flow for more than west to flow. The vertical positive pressure. Strong trend in the diurnal and semidiurnal, clockwise rotation, diurnal trend of the major axis of the ellipse is generally greater than the semidiurnal tidal current, winter K1 tidal amplitude in the near bottom layer increases obviously and the current existence of inertial oscillation obviously in the middle layer. From the perspective of energy conservation, the remaining flow accounted for a larger proportion of total energy current, constant residual current energy mainly exists in the direction of the coast line, which is perpendicular to the shoreline direction of energy is mainly composed of tidal current and residual current. The low frequency current is of obvious seasonal variation is obvious, January 1988 Clockwise form. Winter sea surface wind stress and subsurface flow frequency. There is a strong correlation with OFES (Ocean General Circulation Model for the Earth Simulator) simulation results, using the method of momentum balance analysis on the momentum equation of the low frequency current and the contribution of January 1988 appeared on the surface of north to the power flow mechanism winter. Low frequency flow has strong geostrophic flow characteristics, vertical distribution by seawater layer effect; the combined effect of the northeast wind relaxation and anticyclonic eddies are appeared on the surface of north to the flow of the main reasons.

【作者单位】：中国海洋大学海洋与大气学院;中国海洋大学物理海洋教育部重点实验室;国家海洋局北海海洋工程勘察研究院;
【基金】：国家自然科学基金项目,41606005号,41430963号中国博士后科学基金面上资助项目,2015M582133号
【分类号】：P731.2

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