Characteristics of Storm Surge Events Along the North‐East Atlantic Coasts

Abstract

AbstractStorm surges are often characterized in terms of magnitude, duration and frequency. Here, we propose a novel statistical method to help characterize the full dynamics of storm surge events. The method, called ECHAR, is based on techniques already successfully applied in astrophysics. Analysis of 20 tide gauges in the North‐East Atlantic consistently reveals that storm surge events display two distinctive components, a slow‐time background Gaussian structure and a fast‐time Laplace structure. Each of these structures can be reduced to its duration and amplitude. For large events, occurring 5 times per winter, the slow‐time structure lasts around 16 days, varying from 9 days in the South to 45 days in the North (Baltic Sea), with almost the same amplitude at all the stations (around 0.17 m). The fast‐time structure lasts around 1.7 days at all the stations, but its amplitude greatly varies, from 0.1 m in the South to 1.6 m in the North Sea. The wind stress contributes mostly to the fast‐time component of the storm surge event, whereas the atmospheric pressure contributes to both components. The proposed ECHAR method, helping to characterize extreme events, can be applied anywhere else in the global ocean, for example, where tropical storm surges occur.