STUDY ON OFFSHORE WIND SPEED ESTIMATION USING DIRECTIONAL IDEALIZED WRF-LES

Abstract

 This study proposes a new method for offshore and upper wind speed estimations in a coastal area: The method is based on 16-secotor steady-state wind simulations using the mesoscale model WRF with the LES mode and in-situ wind measurement data available near the coastline. The study area is the coastal area of Hazaki, Kamisu-shi, Ibaraki Prefecture, and the accuracy of the method was validated with measurements from a buoy and a vertical Doppler LiDAR. As a result, it was found that the proposed method can estimate wind speed with a similar accuracy to those reported in previous studies with WRF. On the other hand, it was also found that this method exhibits underestimation tendencies for the horizontal gradient and vertical shear of wind speed, especially when wind blows from the land sector. The result also indicated that the estimation accuracy of this method can be improved by conducting additional simulations for each stability class and by re-examining the dynamical processes and parameters over land surface.