2017 Volume 73 Issue 2 Pages I_157-I_162
In order to estimate the wave climate in a specific region for different purposes such as climate change impact assessment, wave energy assessment, etc., it is important to consider the long-term variations in the range of 10-100 years. Since a specified amount of error in wind modeling (as forcing for numerical wave model) results in a greater amount of error in the wave modeling, two globally available wave analysis data, i.e., ERA-Interim and JRA-55 were considered to discuss about their performance in the study area, where the lack of sufficient wave data exists. The results showed that JRA-55 wave field yields more accurate results than ERA-Interim waves. The regional wave downscaling was carried out using SWAN and two approaches were considered; the local model with locally wind generated wave conditions in lateral boundaries in which, the southern boundary of the computational domain was considered around the Equator, and nested model with a smaller domain, in which, the boundary conditions are given by global model of WW3. The regional downscaling results show that the local model underestimates the wave heights comparing to the measurements and the tuning the physical parameters is required. In order to evaluate the results in the spatial domain, the monthly mean significant wave heights were compared to the satellite monthly mean data by the altimeter. The results showed that the monthly variations by the nested model give reasonable agreement with the satellite data. It can be concluded that the nested model from WW3 to SWAN represents accurate results both in the domain (spatial distribution), and in comparison with high temporal resolution wave data.