Wind and wave climate southeastern of the Mediterranean Sea based on a high-resolution SWAN model

Abstract

Wave and wind data collected over a long time are critical for coastal engineering projects, oceanography, and climate change studies in the coastal zone. Only a few investigations using actual in situ measured data were conducted in the southeastern basin of the Mediterranean along the Egyptian coast. This study aims to develop an accurate wind-wave hindcast SWAN model in Southeastern Mediterranean basin along the Egyptian coast. Three years of in situ measured wind data at Damietta, Egypt, are used to identify the appropriate wind source for the Southeastern Mediterranean Sea from the available ERA-5 and CFSR wind data. The developed SWAN wind-wave model results are calibrated with six-month directional buoy measurements taken at Idku station along the Egyptian coast. Four different sets of exponential wind-wave growth and Whitecapping dissipation coefficients were examined. Grid resolution and time step are tested to obtain the optimal model settings. The results show that ERA5 wind source is more suitable in Southeastern Mediterranean compared to CFSR wind dataset. The degree of agreement between ERA5 wind data and Damietta observations ranges from 0.87 to 0.9. Komen formula in exponential wind wave growth and Janssen in Whitecapping dissipation with Cds = 2.75, are recommended for Southeastern Mediterranean with grid resolution of 0.05° and a 30-minute temporal resolution. Regarding the validation process, it was held at Idku and Damietta buoys for 2 years each. An average index of agreement is 0.93 and 0.67, SI is 0.334 % and 0.18 % and RMSE is 0.22 m and 1.34 s for both the significant wave height and peak wave period, respectively. The calibrated SWAN Model is used to predict wave climate in this region for 30 years from 1990 to 2019.