Sensitivity Analysis of WRF Model to Physical Parameterization for the Characterization of Coastal and Offshore Wind Patterns in Caspian Sea region

Abstract Reliable estimations of wind speed and direction over water bodies are required for scientific and engineering applications. The optimum model parameters are varying for different locations and conditions. In the present study, the Weather Research & Forecasting Model (WRF) was employed to assess different parametrization for the Caspian Sea region for warm and cold periods. All simulations were performed for 9 different configurations for parameters related to the boundary layer. Model evaluation was performed using synoptic stations data, offshore buoy data and ASCAT remote sensing data for two representative 10-day intervals on behalf of winter and summer periods. In the southern coasts of the South Caspian Sea (SCS), the MRF planetary boundary layer (PBL) scheme performed best during winter, while TEMF PBL scheme excelled in summer. The MRF PBL remains a suitable choice for year-round wind pattern simulation, except for the eastern Caspian Sea. In the eastern coasts, winter wind simulation performed well across configurations, but summer results were less favorable, with MYNN and ACM2 PBL schemes preferred for this season. In the western coast, YSU PBL stood out in winter, while MYJ PBL, was recommended for both cold and warm seasons. At the buoy station, MYNN excelled in winter, while MYJ PBL scheme performed best in summer, making it the preferred choice for year-round wind pattern simulation. The comparison with ASCAT data confirmed better model statistics during winter. The results also showed that model simulations were more accurate at offshore buoy location than at coastal stations for all configurations.