Harbor oscillation induced by atmospheric pressure disturbances moving in different directions

Abstract

ABSTRACT A number of observations and theoretical researches have proved that fast moving atmospheric pressure disturbances can excite large tsunami-like water waves in the coastal regions. The oscillation can become more intense inside harbors or bays due to multi-resonant mechanisms. This study mainly focuses on the impact of the disturbance heading direction on water oscillations inside a harbor. A series of cases have been numerically investigated to reveal the significance of the heading direction and the influence of other characteristic parameters. Results show that the harbor oscillation is very sensitive to the disturbance heading direction. The water response is rather intense when the disturbance moves along the coastline. In this situation, notable edge wave trains are excited nearshore and may induce significant resonance if the edge wave frequency is close to one of the eigen frequencies of the harbor. Generally, the response intensity drops with the increase in the angle between the disturbance trajectory and coastline. Meanwhile, the disturbances moving landward usually generate larger water oscillations than the seaward situations. It should be noticed that the most threatening water elevation appears when the disturbance skims over the harbor with a small angle to the coastline landward.