Edge Waves Induced by an Atmospheric Pressure Disturbance Moving at an Oblique Angle to Coastline

Abstract

Edge waves can be generated by atmospheric disturbances travelling approximately parallel to the coastline, which has been analytically and numerically studied by several researchers. Wave amplitude sometimes can be largely amplified by Greenspan resonance, posing a risk to coastal areas. This study focuses on the effect of the angle between the trajectory of atmospheric disturbance and the coastline. A set of numerical experiments based on nonlinear shallow water equations are conducted to investigate the wave induced by an atmospheric pressure disturbance moving at an oblique angle across a slope beach. The main concern is whether notable edge wave packets can be generated or not. And the maximum water elevation near the coastline is also considered. Associating with the analytical solution by Greenspan for disturbances travelling parallel to the coastline, some dominant factors that affect the generation and evolution process of edge waves are discussed firstly. The wave evolution caused by pressure disturbance moving at different angles is shown. And then the angle between the trajectory of atmospheric disturbance and the coastline is further discussed. It is shown that the angle is an important factor to the appearance of notable edge waves and the maximum water elevation near the coastline. The highest water elevation is induced by the pressure disturbance moving from sea to land with a small angle to the coastline.