Day-night redistribution of air pollutants induced by onshore wind farm clusters in winter

Wind power has emerged as a prominent source of renewable energy, eliciting mounting apprehensions regarding its potential atmospheric ramifications. In this study, we employed the mesoscale Weather Research and Forecasting and Community Multiscale Air Quality modeling system, coupled with wind farm parameterization, to explore the effects of wind farm clusters on the diurnal variation of meteorological elements and air pollutants distributions at Zhangbei County in China. The results show that the extraction of wind power from the airflow has a greater impact on the atmosphere at night than during the day. At night, the atmosphere is relatively stable, wind farm clusters cause significant speed deficit, warming, and evaporation, making the atmospheric particulates sink into the lifted atmospheric flow mass and leading to an increase in the PM_2.5 concentration of 1.31 μg/m³. During the daytime, the clusters increase the planetary boundary layer, facilitating the vertical diffusion of pollutants, and a decrease in PM_2.5 of approximately 0.55 μg/m³ is still observed, though the diffusion weakened by the unstable atmosphere. Importantly, wind farm clusters redistribute air pollutants. The pollutant concentration in the wind farm's dense area decreases during the day and increases at night, while its spatial variation is negligible. It provides a feasible method to evaluate the environmental effects and a practical dataset for the diurnal redistribution of air pollutants caused by wind farms.