Validation of a 10-meter wind in simulating a dust event in northwestern Iran mountains (October 28–31, 2017)

This study evaluates the performance of the WRF-Chem model in simulating near-surface winds in Northwest Iran, a region prone to dust events due to its high mountains and diverse structures. Using data from October 28 to 31, 2017, the study first examines dust conditions through visibility and satellite images. The model’s accuracy in simulating 10-meter wind speed and direction in three nested with the MYJ and YSU boundary layer schemes is then assessed against observational data. Results indicate that the primary source of dust on October 29 was desert areas in Iraq and northern Saudi Arabia, with the dust mass transported to Northwest Iran. The study observes the highest intensity and duration of the dust moving from southwest to northeast within the area. The WRF-Chem model shows good performance in simulating wind speed and direction, with the MYJ scheme performing better than YSU in a selected dust case in northern west of Iran. The study also highlights that while improving resolution enhances station altitude values, it alone does not significantly improve model results. In this case, the utilization of a two-way ANOVA revealed that the boundary layer affects the accuracy of 10-meter wind speed estimation at different stations. These findings underscore the importance of considering boundary layer schemes and mountain characteristics in improving the accuracy of models simulating wind patterns in mountainous regions. The WRF-Chem model adequately simulates wind direction in this region, especially when the dominant wind direction at a station falls within a specific geographical dominant sector.