Improving the surface layer scaling of wind speeds in a highly urbanized city based on long-term high-resolution wind LiDAR network

Traditional surface layer scaling law of the wind profiles usually extends up to the top of the surface layer, occupying the lowest ∼10% of the atmospheric boundary layer (ABL). Such scaling based on the Monin-Obukhov (M-O) similarity theory performs satisfactorily in the logarithmic layer, however, it deviates from the true values when turbulence predominates in the overlaying mixed layer. In addition, large discrepancies are observed in extremely stable atmospheric stabilities according to our locally obtained long-term wind profiles. In the proposed study, we aim to deliver a revised scaling that is more accurate under extremely stable conditions and whose applicability can be extended to the upper boundary layer, while the local urban morphology can also be taken into account. Aided by the densely deployed high-resolution wind LiDAR units continuously operating in Hong Kong from 2020 to the present, we will first examine the performance of traditional scaling at various sites featuring drastically different roughness. Subsequently, we propose a novel parameterization that takes the local urban morphology into account in the crucial length scale which considers 1): the collective effects of vortices generated by buildings of heterogeneous heights, and 2): the effective height in which vortices can develop from the ground as a result of buildings occupying a proportion of volume. Ultimately, we will present the difference between the traditional and the newly proposed scaling in mesoscale simulations.