Sensitivity of simulated wind power under diverse spatial scales and multiple terrains using the weather research and forecasting model

Abstract

During the process of grid refinement and downscaling in the Weather Research and Forecasting (WRF) model, the horizontal grid resolution inevitably enters the realm of uncertainty known as the Terra Incognita. Within this region, conventional mesoscale Planetary Boundary Layer schemes fail to achieve the desired optimized outcomes following grid refinement. This study conducted a series of sensitivity analyses to explore the performance of the WRF model in simulating wind speed and direction at different spatial scales under various conditions. By comparing 10 min mean values for flat and complex terrains and then evaluating the performance of the model using statistical scoring. The results indicate that for wind resource assessment, the mesoscale boundary exceeds the height of the atmospheric boundary layer during the simulation period. For flat terrains, nesting is not recommended. Instead, nesting into Terra Incognita and microscale is preferred for complex terrains. The model demonstrates overall accuracy in wind direction estimation but tends to underestimate wind speed. Notably, the accuracy of simulations at 70 m above ground is higher than that at 10 m. The assessment of wind speed and direction exhibits distinct patterns across various wind speed ranges, wind direction, and atmospheric stabilities.