Examining the Effectiveness of Doppler Lidar-Based Observation Nudging in WRF Simulation for Wind Field: A Case Study over Osaka, Japan

This study attempts to improve the accuracy of wind field simulations in the Weather Research and Forecasting (WRF) model by incorporating Doppler lidar-based wind observations over the Osaka region of Japan. To achieve this, a Doppler lidar was deployed in Osaka city, and multi-layer wind measurements were obtained for one month (August 2022). These measurements were then assimilated into the WRF model using the observation nudging technique. Two simulations were conducted: one with nudging disabled, and the other with nudging enabled with data assimilation, while keeping all other configurations constant. The results were evaluated by comparing the simulations with the lidar observation at the lidar location where the wind data were nudged during the simulation, as well as with the AMeDAS station observations at other locations far from the lidar. The results indicated that not only the wind field, but other weather variables such as temperature, were better captured in the simulation using lidar-based nudging compared to the simulation without nudging.