Simulating Impacts of Real-World Wind Farms on Land Surface Temperature Using WRF Model. Part I: Validation with MODIS Observations

This study compares the simulated impacts of real-world wind farms on land surface temperature (LST) using the Weather Research and Forecasting Model (WRF) driven by realistic initial and boundary conditions with satellite observations from Moderate Resolution Imaging Spectroradiometer (MODIS). Simulations are performed over west-central Texas for the month of July throughout seven years (2003-2004 and 2010-2014). Two groups of experiments are conducted: 1) direct validations of WRF-simulated LST changes between the pre-turbine period (2003-2004) and the post-turbine period (2010-2014) against the MODIS observations; 2) a sensitivity test of LST to the current wind turbine parameterization by examining the LST difference with and without the presence of wind turbines for the post-turbine period. For each group, two types of initialization strategy (continuous and three-day reinitialized) are considered. Overall, WRF is generally capable of reproducing the observed spatiotemporal variability of the background LST and turbine-induced nighttime warming in both groups of experiments with both types of initialization. The estimated areal mean wind farm impact on LST from WRF (0.30-0.37℃) is consistent but slightly smaller than that from MODIS (0.39 ℃). These results indicate that WRF has great potentials for assessing real-world wind farm impacts at regional scales. However, the current wind turbine parameterization tends to induce a far downwind (40 km) cooling effect over the wind farm wake region at nighttime, which has not been confirmed by previous observational, satellite and modeling studies.