Both large amplitude depression and elevation internal solitary waves （ISWs） were observed on the continental shelf of the northwest South China Sea （SCS） during the Wenchang Intemal Wave Experiment. In this study...Both large amplitude depression and elevation internal solitary waves （ISWs） were observed on the continental shelf of the northwest South China Sea （SCS） during the Wenchang Intemal Wave Experiment. In this study, we investigate the characteristics of depression and elevation ISWs based on comparisons between observational results and internal wave theories. It is suggested that the large amplitude depression wave is better represented by the extended Korteweg-de Vries （EKdV） theory than by the KdV model, whereas the large amplitude elevation wave is in better agreement with the KdV equation than with the EKdV theory. Wave-induced forces on a supposed small-diameter cylindrical pile by depression and elevation waves are also estimated using the internal wave theory and Morison formula. The wave-induced force by elevation ISWs is rarely reported in the literature. It is found that the force induced by the elevation wave differs significantly fi＇om that by the depression wave, and the elevation wave generally produces greater force on the pile in the lower water column than the depression wave. These results show that ISWs in the study area can present a serious threat to ocean engineering structures, and should not be ignored in the design of oil platforms and ocean operations.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.41106017,41030855)the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX1-YW-12)+1 种基金the Natural Science Foundation of Jiangsu Province of China(No.BK2011396)the National High Technology Research and Development Program of China(863program)(No.2008AA09A401)
文摘Both large amplitude depression and elevation internal solitary waves （ISWs） were observed on the continental shelf of the northwest South China Sea （SCS） during the Wenchang Intemal Wave Experiment. In this study, we investigate the characteristics of depression and elevation ISWs based on comparisons between observational results and internal wave theories. It is suggested that the large amplitude depression wave is better represented by the extended Korteweg-de Vries （EKdV） theory than by the KdV model, whereas the large amplitude elevation wave is in better agreement with the KdV equation than with the EKdV theory. Wave-induced forces on a supposed small-diameter cylindrical pile by depression and elevation waves are also estimated using the internal wave theory and Morison formula. The wave-induced force by elevation ISWs is rarely reported in the literature. It is found that the force induced by the elevation wave differs significantly fi＇om that by the depression wave, and the elevation wave generally produces greater force on the pile in the lower water column than the depression wave. These results show that ISWs in the study area can present a serious threat to ocean engineering structures, and should not be ignored in the design of oil platforms and ocean operations.
