Evaluation of the sea state near Jeddah based on recent observations and model results

This paper presents the analysis of recent wave measurements and results of the application of a wave model in the Red Sea with a focus on the coastal waters of Jeddah in Saudi Arabia. Waves are simulated using Simulating Waves Nearshore within the Delft3D modelling package. Wind fields from the global model of the German Meteorological Service are used to drive the wave model. The model is extensively calibrated and verified with the measured data and satellite altimeters. The influence of the formulation of the wave growth by wind on the model results in the nearshore and offshore zones of Jeddah is investigated. It is also shown that the model reproduces well the refraction occurring over the sharp bathymetric variations in the bay of Jeddah. The analysis of the waves in this bay reveals periodic patterns, on both short and longer time-scales. The wave climate follows a seasonality that is characterized by an increase in the wave action in May and a decrease in November. This longer-term trend is superimposed by a distinct diurnal variation. It is also found that waves near Jeddah that are generated from northern winds are shorter and smaller than waves generated under westerly wind conditions.