Quantifying the impacts of high-resolution urban information on the urban thermal environment

It is particularly relevant for the Weather Research and Forecasting (WRF) model coupled with the single-layer urban canopy model (SLUCM). Thus, we develop high-resolution LULC, AH, and UCP data sets for Nanjing, a megacity in China, and conduct a series of numerical experiments with WRF/SLUCM to evaluate the impacts of urban parameters on the urban thermal environment.

Model simulations with LULC scenarios have good agreement with the observed 2-m temperature (T-2) with a correlation coefficient of around 0.85, and present strong spatial homogeneity due to the more realistic representation of urban categories. The LULC change directly decreases the surface wind speed and increases (decreases) the sensible (latent) heat flux (Q(sH) (Q(LH))) in urban areas during the daytime; meanwhile increases Q(sH) and releases ground heat storage (Q(GH)) during the nighttime, resulting in urban warming by 0.91 degrees C in urban areas, compared with the control simulation (CTL) that does not take into account urban surfaces.