Observing eddy dye patches induced by shear instabilities in the surf zone on a plane beach  

作　　者：Chunping Ren Nannan Fu Chong Yu Yuchuan Bai Kezhao Fang 

机构地区：[1]State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China [2]College of Water Resource Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China [3]State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China

出　　处：《Acta Oceanologica Sinica》2024年第3期15-29,共15页海洋学报（英文版）

基　　金：The open foundation of the State Key Laboratory of Hydraulic Engineering Simulation and Safety under contract No.HESS-2006;the Shanxi Province Science Foundation under contract No.202103021224116;the research project supported by Shanxi Scholarship Council of China under contract No.2023-067.

摘　　要：The effects of surf zone eddy generated by alongshore currents on the deformation and transport of dye are still poorly understood,and related tracer release experiments are lacking.Therefore,a tracer release laboratory experiment was conducted under monochromatic,unidirectional incident waves with a large incident angle(30°)on a plane beach with a 1:100 slope in a large wave basin.A charge-coupled device suspended above the basin recorded the dye patch image.The evolution of eddy dye patch was observed and the transport and diffusion were analyzed based on the collected images.Subsequently,a linear instability numerical model was adopted to calculate the perturbation velocity field at the initial stage.The observation and image processing results show that surf zone eddy patches occurred and were separated from the original dye patches.Our numerical analysis results demonstrate that the structure of the perturbation velocity field is consistent with the experimental observations,and that the ejection of eddy patches shoreward or offshore may be ascribed to the double vortex.

关 键 词：surf zone tracer release experiment evolution of eddy patch shear instability of alongshore currents 

分 类 号：P714[天文地球—海洋科学]