An accurate estimation of the near-surface wind field over the sea is a prerequisite for many engineering and scientific activities in the offshore and coastal areas. As an example, the proper assessment of the wind waves as the most important factor in the design of coastal and offshore structures is highly depended on the accurate estimation of the wind fields. Ocean circulation, morphological processes, coastal management, design and operability of the ports and pollution transport studies are some other activities that directly or indirectly require appropriate knowledge about surface wind field. Therefore, accessibility of the accurate wind data is a major challenge of academic and industrial society.
The main purpose of this study is to simulate the Wind field over the Persian Gulf using WRF meso-scale model and to investigate its effective parameters. This study is a part of a comprehensive project named monitoring and modeling studies of Khuzestan province coastal areas. In this regard, ARW Dynamical core of WRF version 8-3 was used that has been developed by NOAA. Two nested computational domain was defined over Persian Gulf and the neighborhood coastal areas. The coarse domain included 0.3 degree resolution grids and the fine one included 0.1 degree resolution grid. It was found that using ECMWF Era Interim data as the initial and boundary condition of WRF model leads to better results rather than those of FNL data. In Addition, USGS, MODIS and Gtopo30 data sets were employed as static and terrestrial data including Albedo, green fraction, soil humidity, soil temperature, landuse and etc. It was revealed that selection of the appropriate boundary and initial condition and location of the computational domain have significant effect on the simulation of the surface wind field over the Persian Gulf. In order to validate WRF performance in surface wind field simulation over Persian Gulf, the model outputs were compared with different measurements including buoys, synoptic and satellite observations.
The assessment of WRF outputs depicts that WRF model can accurately simulate both stormy and calm winds also during cold and warm seasons that are affected by different atmospheric conditions and global circulations. To quantitatively compare, error Indices represent acceptable performance of WRF model in wind simulation over study area. For example, wind speed correlation coefficient at Bushehr Buoy and AbuDhaby International Airport synoptic stations are 0.82 and 0.78 respectively, while Root Mean Square Error for these stations are 1.60 and 1.56 m/s, respectively. The Bias Parameter for these stations are -0.54 and -0.88, respectively. The Outputs of the WRF model will be used in other hydrodynamic models for simulating waves, currents etc.