LAUSR

Abstract A high-resolution urban canopy parameters (UCPs) dataset for the Pearl River Delta (PRD) was used in a regional model to quantify its impact on meteorological parameters and ozone (O3) concentration. This dataset (PRD_UCPs), with inhomogeneous building morphological parameters (BMPs), is a feasibility test and quality evaluation of the World Urban Database and Access Portal Tools (WUDAPT). We found that the effect of PRD_UCPs on heat fluxes (HF) was significant, with a reduction of 11 W m−2 in the sensible heat flux and an increase of 7.6 W m−2 in the latent heat flux. A decrease in temperature (0.8 °C) and an increase in relative humidity (4.9%) was related to this repartition of HF. The diurnal cycle of HF was delayed by an hour by PRD_UCPs, which was also seen in other meteorological parameters. This dataset also contributed to lower wind speeds, thereby leading to an enhancement in NOx levels. The reduction in O3 concentration (−3.5 μg.m−3) could be explained by the reduction in surface radiation flux. This work highlighted the impact of using UCPs to represent the inhomogeneous urban surface, and the importance of using advanced urban databases in order to aid policy development.